app/vmselect/prometheus: set start arg in /api/v1/series to the minimum allowed time by default as Prometheus does

Fixes https://github.com/VictoriaMetrics/VictoriaMetrics/issues/91

.travis.yml

@@ -0,0 +1,22 @@
+language: go
+
+go:
+  - 1.12.x
+
+install: make
+
+env:
+  - GO111MODULE=on
+
+before_install:
+  - GO111MODULE=off go get -v golang.org/x/lint/golint
+  - GO111MODULE=off go get -u github.com/kisielk/errcheck
+
+script:
+  - make check_all
+  - git diff --exit-code
+  - make test_full
+  - make victoria-metrics
+
+after_success:
+  - bash <(curl -s https://codecov.io/bash)

Makefile

@@ -19,16 +19,20 @@ include deployment/*/Makefile
 clean:
 	rm -rf bin/*
 
+publish: publish-victoria-metrics
+
+package: package-victoria-metrics
+
 release: victoria-metrics-prod
 	cd bin && tar czf victoria-metrics-$(PKG_TAG).tar.gz victoria-metrics-prod
 
 fmt:
-	go fmt $(PKG_PREFIX)/lib/...
-	go fmt $(PKG_PREFIX)/app/...
+	GO111MODULE=on gofmt -l -w -s ./lib
+	GO111MODULE=on gofmt -l -w -s ./app
 
 vet:
-	go vet $(PKG_PREFIX)/lib/...
-	go vet $(PKG_PREFIX)/app/...
+	GO111MODULE=on go vet -mod=vendor ./lib/...
+	GO111MODULE=on go vet -mod=vendor ./app/...
 
 lint: install-golint
 	golint lib/...
@@ -46,19 +50,34 @@ errcheck: install-errcheck
 install-errcheck:
 	which errcheck || GO111MODULE=off go get -u github.com/kisielk/errcheck
 
+check_all: fmt vet lint errcheck golangci-lint
+
 test:
-	go test $(PKG_PREFIX)/lib/...
+	GO111MODULE=on go test -mod=vendor ./lib/...
+	GO111MODULE=on go test -mod=vendor ./app/...
+
+test_full:
+	GO111MODULE=on go test -tags=integration -mod=vendor -coverprofile=coverage.txt -covermode=atomic ./lib/... ./app/...
 
 benchmark:
-	go test -bench=. $(PKG_PREFIX)/lib/...
+	GO111MODULE=on go test -mod=vendor -bench=. ./lib/...
+	GO111MODULE=on go test -mod=vendor -bench=. ./app/...
 
 vendor-update:
-	go get -u
-	go mod tidy
-	go mod vendor
+	GO111MODULE=on go get -u ./lib/...
+	GO111MODULE=on go get -u ./app/...
+	GO111MODULE=on go mod tidy
+	GO111MODULE=on go mod vendor
 
 quicktemplate-gen: install-qtc
 	qtc
 
 install-qtc:
 	which qtc || GO111MODULE=off go get -u github.com/valyala/quicktemplate/qtc
+
+
+golangci-lint: install-golangci-lint
+	golangci-lint run --exclude '(SA4003|SA1019):' -D errcheck
+
+install-golangci-lint:
+	which golangci-lint || GO111MODULE=off go get -u github.com/golangci/golangci-lint/cmd/golangci-lint

README.md

@@ -1,12 +1,16 @@
-<img  text-align="center" alt="Victoria Metrics" src="logo.png">
+[![Latest Release](https://img.shields.io/github/release/VictoriaMetrics/VictoriaMetrics.svg?style=flat-square)](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/latest)
+[![GitHub license](https://img.shields.io/github/license/VictoriaMetrics/VictoriaMetrics.svg)](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/LICENSE)
+[![Go Report](https://goreportcard.com/badge/github.com/VictoriaMetrics/VictoriaMetrics)](https://goreportcard.com/report/github.com/VictoriaMetrics/VictoriaMetrics)
+[![Build Status](https://travis-ci.org/VictoriaMetrics/VictoriaMetrics.svg?branch=master)](https://travis-ci.org/VictoriaMetrics/VictoriaMetrics)
+[![codecov](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics/branch/master/graph/badge.svg)](https://codecov.io/gh/VictoriaMetrics/VictoriaMetrics)
+
+<img alt="Victoria Metrics" src="logo.png">
 
 ## Single-node VictoriaMetrics
 
-[![Latest Release](https://img.shields.io/github/release/VictoriaMetrics/VictoriaMetrics.svg?style=flat-square)](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/latest)
-
-VictoriaMetrics is a long-term remote storage for Prometheus.
+VictoriaMetrics is fast, cost-effective and scalable time series database. It can be used as a long-term remote storage for Prometheus.
 It is available in [binary releases](https://github.com/VictoriaMetrics/VictoriaMetrics/releases),
-[docker images](https://hub.docker.com/r/valyala/victoria-metrics/) and
+[docker images](https://hub.docker.com/r/victoriametrics/victoria-metrics/) and
 in [source code](https://github.com/VictoriaMetrics/VictoriaMetrics).
 
 Cluster version is available [here](https://github.com/VictoriaMetrics/VictoriaMetrics/tree/cluster).
@@ -16,6 +20,7 @@ Cluster version is available [here](https://github.com/VictoriaMetrics/VictoriaM
 
 * Supports [Prometheus querying API](https://prometheus.io/docs/prometheus/latest/querying/api/), so it can be used as Prometheus drop-in replacement in Grafana.
   Additionally, VictoriaMetrics extends PromQL with opt-in [useful features](https://github.com/VictoriaMetrics/VictoriaMetrics/wiki/ExtendedPromQL).
+* Global query view. Multiple Prometheus instances may write data into VictoriaMetrics. Later this data may be used in a single query.
 * High performance and good scalability for both [inserts](https://medium.com/@valyala/high-cardinality-tsdb-benchmarks-victoriametrics-vs-timescaledb-vs-influxdb-13e6ee64dd6b)
   and [selects](https://medium.com/@valyala/when-size-matters-benchmarking-victoriametrics-vs-timescale-and-influxdb-6035811952d4).
   [Outperforms InfluxDB and TimescaleDB by up to 20x](https://medium.com/@valyala/measuring-vertical-scalability-for-time-series-databases-in-google-cloud-92550d78d8ae).
@@ -24,7 +29,8 @@ Cluster version is available [here](https://github.com/VictoriaMetrics/VictoriaM
   may be crammed into a limited storage comparing to TimescaleDB.
 * Optimized for storage with high-latency IO and low iops (HDD and network storage in AWS, Google Cloud, Microsoft Azure, etc). See [graphs from these benchmarks](https://medium.com/@valyala/high-cardinality-tsdb-benchmarks-victoriametrics-vs-timescaledb-vs-influxdb-13e6ee64dd6b).
 * A single-node VictoriaMetrics may substitute moderately sized clusters built with competing solutions such as Thanos, Uber M3, Cortex, InfluxDB or TimescaleDB.
-  See [vertical scalability benchmarks](https://medium.com/@valyala/measuring-vertical-scalability-for-time-series-databases-in-google-cloud-92550d78d8ae).
+  See [vertical scalability benchmarks](https://medium.com/@valyala/measuring-vertical-scalability-for-time-series-databases-in-google-cloud-92550d78d8ae)
+  and [comparing Thanos to VictoriaMetrics cluster](https://medium.com/@valyala/comparing-thanos-to-victoriametrics-cluster-b193bea1683).
 * Easy operation:
   * VictoriaMetrics consists of a single executable without external dependencies.
   * All the configuration is done via explicit command-line flags with reasonable defaults.
@@ -37,7 +43,7 @@ Cluster version is available [here](https://github.com/VictoriaMetrics/VictoriaM
   * [Graphite plaintext protocol](https://graphite.readthedocs.io/en/latest/feeding-carbon.html) with [tags](https://graphite.readthedocs.io/en/latest/tags.html#carbon)
     if `-graphiteListenAddr` is set.
   * [OpenTSDB put message](http://opentsdb.net/docs/build/html/api_telnet/put.html) if `-opentsdbListenAddr` is set.
-* Ideally works with big amounts of time series data from IoT sensors, connected car sensors and industrial sensors.
+* Ideally works with big amounts of time series data from Kubernetes, IoT sensors, connected cars and industrial telemetry.
 * Has open source [cluster version](https://github.com/VictoriaMetrics/VictoriaMetrics/tree/cluster).
 
 
@@ -46,34 +52,49 @@ Cluster version is available [here](https://github.com/VictoriaMetrics/VictoriaM
 
 ### Table of contents
 
-* [How to build from sources](#how-to-build-from-sources)
-* [How to start VictoriaMetrics](#how-to-start-victoriametrics)
-* [Prometheus setup](#prometheus-setup)
-* [Grafana setup](#grafana-setup)
-* [How to send data from InfluxDB-compatible agents such as Telegraf](#how-to-send-data-from-influxdb-compatible-agents-such-as-telegraf)
-* [How to send data from Graphite-compatible agents such as StatsD](#how-to-send-data-from-graphite-compatible-agents-such-as-statsd)
-* [How to send data from OpenTSDB-compatible agents](#how-to-send-data-from-opentsdb-compatible-agents)
-* [How to apply new config / ugrade VictoriaMetrics](#how-to-apply-new-config--upgrade-victoriametrics)
-* [How to work with snapshots](#how-to-work-with-snapshots)
-* [How to delete time series](#how-to-delete-time-series)
-* [How to export time series](#how-to-export-time-series)
-* [Federation](#federation)
-* [Capacity planning](#capacity-planning)
-* [High Availability](#high-availability)
-* [Multiple retentions](#multiple-retentions)
-* [Scalability and cluster version](#scalability-and-cluster-version)
-* [Security](#security)
-* [Tuning](#tuning)
-* [Monitoring](#monitoring)
-* [Troubleshooting](#troubleshooting)
-* [Community and contributions](#community-and-contributions)
-* [Reporting bugs](#reporting-bugs)
+  - [How to build from sources](#how-to-build-from-sources)
+    - [Development build](#development-build)
+    - [Production build](#production-build)
+    - [Building docker images](#building-docker-images)
+  - [How to start VictoriaMetrics](#how-to-start-victoriametrics)
+  - [Setting up service](#setting-up-service)
+  - [Third-party contributions](#third-party-contributions)
+  - [Prometheus setup](#prometheus-setup)
+  - [Grafana setup](#grafana-setup)
+  - [How to upgrade VictoriaMetrics?](#how-to-upgrade-victoriametrics)
+  - [How to apply new config to VictoriaMetrics?](#how-to-apply-new-config-to-victoriametrics)
+  - [How to send data from InfluxDB-compatible agents such as Telegraf?](#how-to-send-data-from-influxdb-compatible-agents-such-as-telegraf)
+  - [How to send data from Graphite-compatible agents such as StatsD?](#how-to-send-data-from-graphite-compatible-agents-such-as-statsd)
+  - [How to send data from OpenTSDB-compatible agents?](#how-to-send-data-from-opentsdb-compatible-agents)
+  - [How to work with snapshots?](#how-to-work-with-snapshots)
+  - [How to delete time series?](#how-to-delete-time-series)
+  - [How to export time series?](#how-to-export-time-series)
+  - [Federation](#federation)
+  - [Capacity planning](#capacity-planning)
+  - [High availability](#high-availability)
+  - [Multiple retentions](#multiple-retentions)
+  - [Downsampling](#downsampling)
+  - [Multi-tenancy](#multi-tenancy)
+  - [Scalability and cluster version](#scalability-and-cluster-version)
+  - [Alerting](#alerting)
+  - [Security](#security)
+  - [Tuning](#tuning)
+  - [Monitoring](#monitoring)
+  - [Troubleshooting](#troubleshooting)
+- [Contacts](#contacts)
+- [Community and contributions](#community-and-contributions)
+- [Reporting bugs](#reporting-bugs)
+- [Victoria Metrics Logo](#victoria-metrics-logo)
+  - [Logo Usage Guidelines](#logo-usage-guidelines)
+    - [Font used:](#font-used)
+    - [Color Palette:](#color-palette)
+  - [We kindly ask:](#we-kindly-ask)
 
 
 ### How to build from sources
 
 We recommend using either [binary releases](https://github.com/VictoriaMetrics/VictoriaMetrics/releases) or
-[docker images](https://hub.docker.com/r/valyala/victoria-metrics/) instead of building VictoriaMetrics
+[docker images](https://hub.docker.com/r/victoriametrics/victoria-metrics/) instead of building VictoriaMetrics
 from sources. Building from sources is reasonable when developing an additional features specific
 to your needs.
 
@@ -81,21 +102,20 @@ to your needs.
 #### Development build
 
 1. [Install Go](https://golang.org/doc/install). The minimum supported version is Go 1.12.
-2. Run `go build ./app/victoria-metrics` from the root folder of the repository.
-   It will build `victoria-metrics` binary in the root folder of the repository.
+2. Run `make victoria-metrics` from the root folder of the repository.
+   It will build `victoria-metrics` binary and put it into the `bin` folder.
 
 #### Production build
 
 1. [Install docker](https://docs.docker.com/install/).
-2. Run `make victoria-metrics-prod` from the root folder of the respository.
+2. Run `make victoria-metrics-prod` from the root folder of the repository.
    It will build `victoria-metrics-prod` binary and put it into the `bin` folder.
 
 #### Building docker images
 
-Run `make package-victoria-metrics`. It will build `valyala/victoria-metrics:<PKG_TAG>` docker image locally.
+Run `make package-victoria-metrics`. It will build `victoriametrics/victoria-metrics:<PKG_TAG>` docker image locally.
 `<PKG_TAG>` is auto-generated image tag, which depends on source code in the repository.
-The `<PKG_TAG>` may be manually set via `PKG_TAG=foobar make package`.
-
+The `<PKG_TAG>` may be manually set via `PKG_TAG=foobar make package-victoria-metrics`.
 
 
 ### How to start VictoriaMetrics
@@ -113,6 +133,16 @@ The following command line flags are used the most:
 Pass `-help` to see all the available flags with description and default values.
 
 
+### Setting up service
+
+Read [these instructions](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/43) on how to set up VictoriaMetrics as a service in your OS.
+
+
+### Third-party contributions
+
+* [Unofficial yum repository](https://copr.fedorainfracloud.org/coprs/antonpatsev/VictoriaMetrics/) ([source code](https://github.com/patsevanton/victoriametrics-rpm))
+
+
 ### Prometheus setup
 
 Add the following lines to Prometheus config file (it is usually located at `/etc/prometheus/prometheus.yml`):
@@ -122,6 +152,7 @@ remote_write:
   - url: http://<victoriametrics-addr>:8428/api/v1/write
     queue_config:
       max_samples_per_send: 10000
+      max_shards: 100
 ```
 
 Substitute `<victoriametrics-addr>` with the hostname or IP address of VictoriaMetrics.
@@ -149,6 +180,10 @@ The label name may be arbitrary - `datacenter` is just an example. The label val
 across Prometheus instances, so time series may be filtered and grouped by this label.
 
 
+It is recommended upgrading Prometheus to [v2.10.0](https://github.com/prometheus/prometheus/releases) or newer,
+since the previous versions may have issues with `remote_write`.
+
+
 ### Grafana setup
 
 Create [Prometheus datasource](http://docs.grafana.org/features/datasources/prometheus/) in Grafana with the following Url:
@@ -163,6 +198,28 @@ Then build graphs with the created datasource using [Prometheus query language](
 VictoriaMetrics supports native PromQL and [extends it with useful features](ExtendedPromQL).
 
 
+### How to upgrade VictoriaMetrics?
+
+It is safe upgrading VictoriaMetrics to new versions unless [release notes](https://github.com/VictoriaMetrics/VictoriaMetrics/releases)
+say otherwise. It is recommended performing regular upgrades to the latest version,
+since it may contain important bug fixes, performance optimizations or new features.
+
+Follow the following steps during the upgrade:
+
+1) Send `SIGINT` signal to VictoriaMetrics process in order to gracefully stop it.
+2) Wait until the process stops. This can take a few seconds.
+3) Start the upgraded VictoriaMetrics.
+
+
+### How to apply new config to VictoriaMetrics?
+
+VictoriaMetrics must be restarted for applying new config:
+
+1) Send `SIGINT` signal to VictoriaMetrics process in order to gracefully stop it.
+2) Wait until the process stops. This can take a few seconds.
+3) Start VictoriaMetrics with new config.
+
+
 ### How to send data from InfluxDB-compatible agents such as [Telegraf](https://www.influxdata.com/time-series-platform/telegraf/)?
 
 Just use `http://<victoriametric-addr>:8428` url instead of InfluxDB url in agents' configs.
@@ -176,10 +233,46 @@ For instance, put the following lines into `Telegraf` config, so it sends data t
 Do not forget substituting `<victoriametrics-addr>` with the real address where VictoriaMetrics runs.
 
 VictoriaMetrics maps Influx data using the following rules:
-* [`db` query arg](https://docs.influxdata.com/influxdb/v1.7/tools/api/#write-http-endpoint) is mapped into `db` label value
-* Field names are mapped to time series names prefixed by `{measurement}.` value
-* Field values are mapped to time series values
-* Tags are mapped to Prometheus labels as-is
+* [`db` query arg](https://docs.influxdata.com/influxdb/v1.7/tools/api/#write-http-endpoint) is mapped into `db` label value.
+* Field names are mapped to time series names prefixed with `{measurement}{separator}` value,
+  where `{separator}` equals to `_` by default. It can be changed with `-influxMeasurementFieldSeparator` command-line flag.
+  See also `-influxSkipSingleField` command-line flag.
+* Field values are mapped to time series values.
+* Tags are mapped to Prometheus labels as-is.
+
+For example, the following Influx line:
+
+```
+foo,tag1=value1,tag2=value2 field1=12,field2=40
+```
+
+is converted into the following Prometheus data points:
+
+```
+foo.field1{tag1="value1", tag2="value2"} 12
+foo.field2{tag1="value1", tag2="value2"} 40
+```
+
+Example for writing data with [Influx line protocol](https://docs.influxdata.com/influxdb/v1.7/write_protocols/line_protocol_tutorial/)
+to local VictoriaMetrics using `curl`:
+
+```
+curl -d 'measurement,tag1=value1,tag2=value2 field1=123,field2=1.23' -X POST 'http://localhost:8428/write'
+```
+
+Arbitrary number of lines delimited by '\n' may be sent in a single request.
+After that the data may be read via [/api/v1/export](#how-to-export-time-series) endpoint:
+
+```
+curl -G 'http://localhost:8428/api/v1/export' --data-urlencode 'match={__name__!=""}'
+```
+
+The `/api/v1/export` endpoint should return the following response:
+
+```
+{"metric":{"__name__":"measurement.field1","tag1":"value1","tag2":"value2"},"values":[123],"timestamps":[1560272508147]}
+{"metric":{"__name__":"measurement.field2","tag1":"value1","tag2":"value2"},"values":[1.23],"timestamps":[1560272508147]}
+```
 
 
 ### How to send data from Graphite-compatible agents such as [StatsD](https://github.com/etsy/statsd)?
@@ -188,36 +281,70 @@ VictoriaMetrics maps Influx data using the following rules:
 the following command will enable Graphite receiver in VictoriaMetrics on TCP and UDP port `2003`:
 
 ```
-/path/to/victoria-metrics-prod ... -graphiteListenAddr=:2003
+/path/to/victoria-metrics-prod -graphiteListenAddr=:2003
 ```
 
 2) Use the configured address in Graphite-compatible agents. For instance, set `graphiteHost`
 to the VictoriaMetrics host in `StatsD` configs.
 
 
+Example for writing data with Graphite plaintext protocol to local VictoriaMetrics using `nc`:
+
+```
+echo "foo.bar.baz;tag1=value1;tag2=value2 123 `date +%s`" | nc -N localhost 2003
+```
+
+VictoriaMetrics sets the current time if timestamp is omitted.
+Arbitrary number of lines delimited by `\n` may be sent in one go.
+After that the data may be read via [/api/v1/export](#how-to-export-time-series) endpoint:
+
+```
+curl -G 'http://localhost:8428/api/v1/export' --data-urlencode 'match={__name__!=""}'
+```
+
+The `/api/v1/export` endpoint should return the following response:
+
+```
+{"metric":{"__name__":"foo.bar.baz","tag1":"value1","tag2":"value2"},"values":[123],"timestamps":[1560277406000]}
+```
+
+
 ### How to send data from OpenTSDB-compatible agents?
 
 1) Enable OpenTSDB receiver in VictoriaMetrics by setting `-opentsdbListenAddr` command line flag. For instance,
 the following command will enable OpenTSDB receiver in VictoriaMetrics on TCP and UDP port `4242`:
 
 ```
-/path/to/victoria-metrics-prod ... -opentsdbListenAddr=:4242
+/path/to/victoria-metrics-prod -opentsdbListenAddr=:4242
 ```
 
 2) Send data to the given address from OpenTSDB-compatible agents.
 
 
-### How to apply new config / upgrade VictoriaMetrics?
+Example for writing data with OpenTSDB protocol to local VictoriaMetrics using `nc`:
 
-VictoriaMetrics must be restarted in order to upgrade or apply new config:
+```
+echo "put foo.bar.baz `date +%s` 123 tag1=value1 tag2=value2" | nc -N localhost 4242
+```
 
-1) Send `SIGINT` signal to VictoriaMetrics process in order to gracefully stop it.
-2) Wait until the process stops. This can take a few seconds.
-3) Start the upgraded VictoriaMetrics with new config.
+Arbitrary number of lines delimited by `\n` may be sent in one go.
+After that the data may be read via [/api/v1/export](#how-to-export-time-series) endpoint:
+
+```
+curl -G 'http://localhost:8428/api/v1/export' --data-urlencode 'match={__name__!=""}'
+```
+
+The `/api/v1/export` endpoint should return the following response:
+
+```
+{"metric":{"__name__":"foo.bar.baz","tag1":"value1","tag2":"value2"},"values":[123],"timestamps":[1560277292000]}
+```
 
 
 ### How to work with snapshots?
 
+VictoriaMetrics is able to create [instant snapshots](https://medium.com/@valyala/how-victoriametrics-makes-instant-snapshots-for-multi-terabyte-time-series-data-e1f3fb0e0282)
+for all the data stored under `-storageDataPath` directory.
 Navigate to `http://<victoriametrics-addr>:8428/snapshot/create` in order to create an instant snapshot.
 The page will return the following JSON response:
 
@@ -226,7 +353,7 @@ The page will return the following JSON response:
 ```
 
 Snapshots are created under `<-storageDataPath>/snapshots` directory, where `<-storageDataPath>`
-is the command-line flag value. Snapshots can be archived to backup storage via `rsync -L`, `scp -r`
+is the command-line flag value. Snapshots can be archived to backup storage via `cp -L`, `rsync -L`, `scp -r`
 or any similar tool that follows symlinks during copying.
 
 The `http://<victoriametrics-addr>:8428/snapshot/list` page contains the list of available snapshots.
@@ -236,6 +363,12 @@ to delete `<snapshot-name>` snapshot.
 
 Navigate to `http://<victoriametrics-addr>:8428/snapshot/delete_all` in order to delete all the snapshots.
 
+Steps for restoring from a snapshot:
+1. Stop VictoriaMetrics with `kill -INT`.
+2. Remove the entire contents of the directory pointed by `-storageDataPath` command-line flag.
+3. Copy snapshot contents to the directory pointed by `-storageDataPath`.
+4. Start VictoriaMetrics.
+
 
 ### How to delete time series?
 
@@ -268,7 +401,7 @@ at `http://<victoriametrics-addr>:8428/federate?match[]=<timeseries_selector_for
 
 Optional `start` and `end` args may be added to the request in order to scrape the last point for each selected time series on the `[start ... end]` interval.
 `start` and `end` may contain either unix timestamp in seconds or [RFC3339](https://www.ietf.org/rfc/rfc3339.txt) values. By default the last point
-on the interval `[now - max_lookback ... now]` is scraped for each time series. Default value for `max_lookback` is `5m` (5 minutes), but can be overriden.
+on the interval `[now - max_lookback ... now]` is scraped for each time series. Default value for `max_lookback` is `5m` (5 minutes), but can be overridden.
 For instance, `/federate?match[]=up&max_lookback=1h` would return last points on the `[now - 1h ... now]` interval. This may be useful for time series federation
 with scrape intervals exceeding `5m`.
 
@@ -279,19 +412,26 @@ Rough estimation of the required resources:
 
 * RAM size: less than 1KB per active time series. So, ~1GB of RAM is required for 1M active time series.
   Time series is considered active if new data points have been added to it recently or if it has been recently queried.
-  VictoriaMetrics stores various caches in RAM. Memory size for these caches may be limited with `-memory.allowedPercent` flag.
+  The number of active time series may be obtained from `vm_cache_entries{type="storage/hour_metric_ids"}` metric
+  exproted on the `/metrics` page.
+  VictoriaMetrics stores various caches in RAM. Memory size for these caches may be limited by `-memory.allowedPercent` flag.
+
 * CPU cores: a CPU core per 300K inserted data points per second. So, ~4 CPU cores are required for processing
-  the insert stream of 1M data points per second.
+  the insert stream of 1M data points per second. The ingestion rate may be lower for high cardinality data.
+  See [this article](https://medium.com/@valyala/insert-benchmarks-with-inch-influxdb-vs-victoriametrics-e31a41ae2893) for details.
   If you see lower numbers per CPU core, then it is likely active time series info doesn't fit caches,
   so you need more RAM for lowering CPU usage.
+
 * Storage size: less than a byte per data point on average. So, ~260GB is required for storing a month-long insert stream
   of 100K data points per second.
   The actual storage size heavily depends on data randomness (entropy). Higher randomness means higher storage size requirements.
+  Read [this article](https://medium.com/faun/victoriametrics-achieving-better-compression-for-time-series-data-than-gorilla-317bc1f95932)
+  for details.
 
 
 ### High availability
 
-1) Install multiple VictoriaMetrics instances in distinct datacenters.
+1) Install multiple VictoriaMetrics instances in distinct datacenters (availability zones).
 2) Add addresses of these instances to `remote_write` section in Prometheus config:
 
 ```yml
@@ -316,6 +456,10 @@ kill -HUP `pidof prometheus`
 6) Set up Prometheus datasource in Grafana that points to Promxy.
 
 
+If you have Prometheus HA pairs with replicas `r1` and `r2` in each pair, then configure each `r1`
+to write data to `<victoriametrics-addr-1`, while each `r2` should write data to `victoriametrics-addr-2`.
+
+
 ### Multiple retentions
 
 Just start multiple VictoriaMetrics instances with distinct values for the following flags:
@@ -325,17 +469,40 @@ Just start multiple VictoriaMetrics instances with distinct values for the follo
 * `-httpListenAddr`, so clients may reach VictoriaMetrics instance with proper retention
 
 
+### Downsampling
+
+There is no downsampling support at the moment, but:
+- VictoriaMetrics is optimized for querying big amounts of raw data. See benchmark results for heavy queries
+  in [this article](https://medium.com/@valyala/measuring-vertical-scalability-for-time-series-databases-in-google-cloud-92550d78d8ae).
+- VictoriaMetrics has good compression for on-disk data. See [this article](https://medium.com/@valyala/victoriametrics-achieving-better-compression-for-time-series-data-than-gorilla-317bc1f95932)
+  for details.
+
+These properties reduce the need in downsampling. We plan implementing downsampling in the future.
+See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/36) for details.
+
+
+### Multi-tenancy
+
+Single-node VictoriaMetrics doesn't support multi-tenancy. Use [cluster version](https://github.com/VictoriaMetrics/VictoriaMetrics/tree/cluster) instead.
+
+
 ### Scalability and cluster version
 
 Though single-node VictoriaMetrics cannot scale to multiple nodes, it is optimized for resource usage - storage size / bandwidth / IOPS, RAM, CPU.
 This means that a single-node VictoriaMetrics may scale vertically and substitute moderately sized cluster built with competing solutions
-such as Thanos, Uber M3, InfluxDB or TimescaleDB.
+such as Thanos, Uber M3, InfluxDB or TimescaleDB. See [vertical scalability benchmarks](https://medium.com/@valyala/measuring-vertical-scalability-for-time-series-databases-in-google-cloud-92550d78d8ae).
 
 So try single-node VictoriaMetrics at first and then [switch to cluster version](https://github.com/VictoriaMetrics/VictoriaMetrics/tree/cluster) if you still need
 horizontally scalable long-term remote storage for really large Prometheus deployments.
 [Contact us](mailto:info@victoriametrics.com) for paid support.
 
 
+### Alerting
+
+VictoriaMetrics doesn't support rule evaluation and alerting yet, so these actions must be performed either
+on [Prometheus side](https://prometheus.io/docs/alerting/overview/) or on [Grafana side](https://grafana.com/docs/alerting/rules/).
+
+
 ### Security
 
 Do not forget protecting sensitive endpoints in VictoriaMetrics when exposing it to untrusted networks such as internet.
@@ -366,6 +533,21 @@ VictoriaMetrics exports internal metrics in Prometheus format on the `/metrics`
 Add this page to Prometheus' scrape config in order to collect VictoriaMetrics metrics.
 There is [an official Grafana dashboard for single-node VictoriaMetrics](https://grafana.com/dashboards/10229).
 
+The most interesting metrics are:
+
+* `vm_cache_entries{type="storage/hour_metric_ids"}` - the number of time series with new data points during the last hour
+  aka active time series.
+* `vm_rows{type="indexdb"}` - the number of rows in inverted index. Each label in each unique time series adds a single
+  row into the inverted index. An approximate number of time series in the database may be calculated as
+  `vm_rows{type="indexdb"} / (avg_labels_per_series + 1)`, where `avg_labels_per_series` is the average number of labels
+  per each time series.
+* Sum of `vm_rows{type="storage/big"}` and `vm_rows{type="storage/small"}` - total number of `(timestamp, value)` data points
+  in the database.
+* Sum of all the `vm_cache_size_bytes` metrics - the total size of all the caches in the database.
+* `vm_allowed_memory_bytes` - the maximum allowed size for caches in the database. It is calculated as `system_memory * <-memory.allowedPercent> / 100`,
+  where `system_memory` is the amount of system memory and `-memory.allowedPercent` is the corresponding flag value.
+* `vm_rows_inserted_total` - the total number of inserted rows since VictoriaMetrics start.
+
 
 ### Troubleshooting
 
@@ -376,10 +558,32 @@ There is [an official Grafana dashboard for single-node VictoriaMetrics](https:/
   Another option is to increase `-memory.allowedPercent` command-line flag value. Be careful with this
   option, since too big value for `-memory.allowedPercent` may result in high I/O usage.
 
+* If VictoriaMetrics doesn't work because of certain parts are corrupted due to disk errors,
+  then just remove directoreis with broken parts. This will recover VictoriaMetrics at the cost
+  of data loss stored in the broken parts. In the future `vmrecover` tool will be created
+  for automatic recovering from such errors.
+
+
+## Contacts
+
+Contact us with any questions regarding VictoriaMetrics at [info@victoriametrics.com](mailto:info@victoriametrics.com).
+
 
 ## Community and contributions
 
-Feel free asking any questions regarding VictoriaMetrics [here](https://groups.google.com/forum/#!forum/victorametrics-users).
+Feel free asking any questions regarding VictoriaMetrics:
+
+- [slack](http://slack.victoriametrics.com/)
+- [telergam-en](https://t.me/VictoriaMetrics_en)
+- [telergam-ru](https://t.me/VictoriaMetrics_ru1)
+- [google groups](https://groups.google.com/forum/#!forum/victorametrics-users)
+
+
+If you like VictoriaMetrics and want contributing, then we need the following:
+
+- Filing issues and feature requests [here](https://github.com/VictoriaMetrics/VictoriaMetrics/issues).
+- Spreading a word about VictoriaMetrics: conference talks, articles, comments, experience sharing with colleagues.
+- Updating documentation.
 
 We are open to third-party pull requests provided they follow [KISS design principle](https://en.wikipedia.org/wiki/KISS_principle):
 

app/victoria-metrics/Makefile

@@ -1,5 +1,8 @@
 # All these commands must run from repository root.
 
+victoria-metrics:
+	GO111MODULE=on go build -mod=vendor -ldflags "$(GO_BUILDINFO)" -o bin/victoria-metrics ./app/victoria-metrics
+
 victoria-metrics-prod:
 	APP_NAME=victoria-metrics $(MAKE) app-via-docker
 
@@ -12,10 +15,13 @@ publish-victoria-metrics:
 
 run-victoria-metrics:
 	mkdir -p victoria-metrics-data
-	DOCKER_OPTS='-v $(shell pwd)/victoria-metrics-data:/victoria-metrics-data -p 8428:8428 -p 2003:2003 -p 2003:2003/udp' \
+	DOCKER_OPTS='-v $(shell pwd)/victoria-metrics-data:/victoria-metrics-data' \
 	APP_NAME=victoria-metrics \
 	ARGS='-graphiteListenAddr=:2003 -opentsdbListenAddr=:4242 -retentionPeriod=12 -search.maxUniqueTimeseries=1000000 -search.maxQueryDuration=10m' \
 	$(MAKE) run-via-docker
 
 victoria-metrics-arm:
 	CC=arm-linux-gnueabi-gcc CGO_ENABLED=1 GOARCH=arm GO111MODULE=on go build -mod=vendor -ldflags "$(GO_BUILDINFO)" -o bin/victoria-metrics-arm ./app/victoria-metrics
+
+victoria-metrics-arm64:
+	CC=aarch64-linux-gnu-gcc CGO_ENABLED=1 GOARCH=arm64 GO111MODULE=on go build -mod=vendor -ldflags "$(GO_BUILDINFO)" -o bin/victoria-metrics-arm64 ./app/victoria-metrics

app/victoria-metrics/main_test.go

@@ -0,0 +1,281 @@
+// +build integration
+
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vminsert"
+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect"
+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmstorage"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/httpserver"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+)
+
+const (
+	testFixturesDir        = "testdata"
+	testStorageSuffix      = "vm-test-storage"
+	testHTTPListenAddr     = ":7654"
+	testStatsDListenAddr   = ":2003"
+	testOpenTSDBListenAddr = ":4242"
+	testLogLevel           = "INFO"
+)
+
+const (
+	testReadHTTPPath   = "http://127.0.0.1" + testHTTPListenAddr
+	testWriteHTTPPath  = "http://127.0.0.1" + testHTTPListenAddr + "/write"
+	testHealthHTTPPath = "http://127.0.0.1" + testHTTPListenAddr + "/health"
+)
+
+const (
+	testStorageInitTimeout = 10 * time.Second
+)
+
+var (
+	storagePath   string
+	insertionTime = time.Now().UTC()
+)
+
+type test struct {
+	Name   string `json:"name"`
+	Data   string `json:"data"`
+	Query  string `json:"query"`
+	Result []Row  `json:"result"`
+}
+
+type Row struct {
+	Metric     map[string]string `json:"metric"`
+	Values     []float64         `json:"values"`
+	Timestamps []int64           `json:"timestamps"`
+}
+
+func TestMain(m *testing.M) {
+	setUp()
+	code := m.Run()
+	tearDown()
+	os.Exit(code)
+}
+
+func setUp() {
+	storagePath = filepath.Join(os.TempDir(), testStorageSuffix)
+	processFlags()
+	logger.Init()
+	vmstorage.InitWithoutMetrics()
+	vmselect.Init()
+	vminsert.Init()
+	go httpserver.Serve(*httpListenAddr, requestHandler)
+	readyStorageCheckFunc := func() bool {
+		resp, err := http.Get(testHealthHTTPPath)
+		if err != nil {
+			return false
+		}
+		resp.Body.Close()
+		return resp.StatusCode == 200
+	}
+	if err := waitFor(testStorageInitTimeout, readyStorageCheckFunc); err != nil {
+		log.Fatalf("http server can't start for %s seconds, err %s", testStorageInitTimeout, err)
+	}
+}
+
+func processFlags() {
+	flag.Parse()
+	for _, fs := range []struct {
+		flag  string
+		value string
+	}{
+		{flag: "storageDataPath", value: storagePath},
+		{flag: "httpListenAddr", value: testHTTPListenAddr},
+		{flag: "graphiteListenAddr", value: testStatsDListenAddr},
+		{flag: "opentsdbListenAddr", value: testOpenTSDBListenAddr},
+		{flag: "loggerLevel", value: testLogLevel},
+	} {
+		// panics if flag doesn't exist
+		if err := flag.Lookup(fs.flag).Value.Set(fs.value); err != nil {
+			log.Fatalf("unable to set %q with value %q, err: %v", fs.flag, fs.value, err)
+		}
+	}
+}
+
+func waitFor(timeout time.Duration, f func() bool) error {
+	fraction := timeout / 10
+	for i := fraction; i < timeout; i += fraction {
+		if f() {
+			return nil
+		}
+		time.Sleep(fraction)
+	}
+	return fmt.Errorf("timeout")
+}
+
+func tearDown() {
+	vminsert.Stop()
+	vmstorage.Stop()
+	vmselect.Stop()
+	if err := httpserver.Stop(*httpListenAddr); err != nil {
+		log.Fatalf("cannot stop the webservice: %s", err)
+	}
+	os.RemoveAll(storagePath)
+}
+
+func TestWriteRead(t *testing.T) {
+	t.Run("write", testWrite)
+	time.Sleep(1 * time.Second)
+	vmstorage.Stop()
+
+	// open storage after stop in write
+	vmstorage.InitWithoutMetrics()
+	t.Run("read", testRead)
+}
+
+func testWrite(t *testing.T) {
+	t.Run("influxdb", func(t *testing.T) {
+		for _, test := range readIn("influxdb", t, fmt.Sprintf("%d", insertionTime.UnixNano())) {
+			t.Run(test.Name, func(t *testing.T) {
+				t.Parallel()
+				httpWrite(t, testWriteHTTPPath, test.Data)
+			})
+		}
+	})
+	t.Run("graphite", func(t *testing.T) {
+		for _, test := range readIn("graphite", t, fmt.Sprintf("%d", insertionTime.Unix())) {
+			t.Run(test.Name, func(t *testing.T) {
+				t.Parallel()
+				tcpWrite(t, "127.0.0.1"+testStatsDListenAddr, test.Data)
+			})
+		}
+	})
+	t.Run("opentsdb", func(t *testing.T) {
+		for _, test := range readIn("opentsdb", t, fmt.Sprintf("%d", insertionTime.Unix())) {
+			t.Run(test.Name, func(t *testing.T) {
+				t.Parallel()
+				tcpWrite(t, "127.0.0.1"+testOpenTSDBListenAddr, test.Data)
+			})
+		}
+	})
+}
+
+func testRead(t *testing.T) {
+	for _, engine := range []string{"graphite", "opentsdb", "influxdb"} {
+		t.Run(engine, func(t *testing.T) {
+			for _, test := range readIn(engine, t, fmt.Sprintf("%d", insertionTime.UnixNano())) {
+				test := test
+				t.Run(test.Name, func(t *testing.T) {
+					t.Parallel()
+					rowContains(t, httpRead(t, testReadHTTPPath, test.Query), test.Result)
+				})
+			}
+		})
+	}
+}
+
+func readIn(readFor string, t *testing.T, timeStr string) []test {
+	t.Helper()
+	s := newSuite(t)
+	var tt []test
+	s.noError(filepath.Walk(filepath.Join(testFixturesDir, readFor), func(path string, info os.FileInfo, err error) error {
+		if filepath.Ext(path) != ".json" {
+			return nil
+		}
+		b, err := ioutil.ReadFile(path)
+		s.noError(err)
+		item := test{}
+		s.noError(json.Unmarshal(b, &item))
+		item.Data = strings.Replace(item.Data, "{TIME}", timeStr, 1)
+		tt = append(tt, item)
+		return nil
+	}))
+	if len(tt) == 0 {
+		t.Fatalf("no test found in %s", filepath.Join(testFixturesDir, readFor))
+	}
+	return tt
+}
+
+func httpWrite(t *testing.T, address string, data string) {
+	t.Helper()
+	s := newSuite(t)
+	resp, err := http.Post(address, "", bytes.NewBufferString(data))
+	s.noError(err)
+	s.noError(resp.Body.Close())
+	s.equalInt(resp.StatusCode, 204)
+}
+
+func tcpWrite(t *testing.T, address string, data string) {
+	t.Helper()
+	s := newSuite(t)
+	conn, err := net.Dial("tcp", address)
+	s.noError(err)
+	defer conn.Close()
+	n, err := conn.Write([]byte(data))
+	s.noError(err)
+	s.equalInt(n, len(data))
+}
+
+func httpRead(t *testing.T, address, query string) []Row {
+	t.Helper()
+	s := newSuite(t)
+	resp, err := http.Get(address + query)
+	s.noError(err)
+	defer resp.Body.Close()
+	s.equalInt(resp.StatusCode, 200)
+	var rows []Row
+	for dec := json.NewDecoder(resp.Body); dec.More(); {
+		var row Row
+		s.noError(dec.Decode(&row))
+		rows = append(rows, row)
+	}
+	return rows
+}
+
+func rowContains(t *testing.T, rows, contains []Row) {
+	t.Helper()
+	for _, r := range rows {
+		contains = removeIfFound(r, contains)
+	}
+	if len(contains) > 0 {
+		t.Fatalf("result rows %+v not found in %+v", contains, rows)
+	}
+}
+
+func removeIfFound(r Row, contains []Row) []Row {
+	for i, item := range contains {
+		// todo check time
+		if reflect.DeepEqual(r.Metric, item.Metric) && reflect.DeepEqual(r.Values, item.Values) {
+			contains[i] = contains[len(contains)-1]
+			return contains[:len(contains)-1]
+		}
+	}
+	return contains
+}
+
+type suite struct{ t *testing.T }
+
+func newSuite(t *testing.T) *suite { return &suite{t: t} }
+
+func (s *suite) noError(err error) {
+	s.t.Helper()
+	if err != nil {
+		s.t.Errorf("unexpected error %v", err)
+		s.t.FailNow()
+	}
+}
+
+func (s *suite) equalInt(a, b int) {
+	s.t.Helper()
+	if a != b {
+		s.t.Errorf("%d not equal %d", a, b)
+		s.t.FailNow()
+	}
+}

app/victoria-metrics/testdata/graphite/basic.json

@@ -0,0 +1,8 @@
+{
+  "name": "basic_insertion",
+  "data": "graphite.foo.bar.baz;tag1=value1;tag2=value2 123 {TIME}",
+  "query": "/api/v1/export?match={__name__!=\"\"}",
+  "result": [
+    {"metric":{"__name__":"graphite.foo.bar.baz","tag1":"value1","tag2":"value2"},"values":[123]}
+  ]
+}

app/victoria-metrics/testdata/influxdb/basic.json

@@ -0,0 +1,9 @@
+{
+  "name": "basic_insertion",
+  "data": "measurement,tag1=value1,tag2=value2 field1=1.23,field2=123",
+  "query": "/api/v1/export?match={__name__!=\"\"}",
+  "result": [
+    {"metric":{"__name__":"measurement_field2","tag1":"value1","tag2":"value2"},"values":[123]},
+    {"metric":{"__name__":"measurement_field1","tag1":"value1","tag2":"value2"},"values":[1.23]}
+  ]
+}

app/victoria-metrics/testdata/opentsdb/basic.json

@@ -0,0 +1,8 @@
+{
+  "name": "basic_insertion",
+  "data": "put openstdb.foo.bar.baz {TIME} 123 tag1=value1 tag2=value2",
+  "query": "/api/v1/export?match={__name__!=\"\"}",
+  "result": [
+    {"metric":{"__name__":"openstdb.foo.bar.baz","tag1":"value1","tag2":"value2"},"values":[123]}
+  ]
+}

app/vminsert/common/insert_ctx.go

@@ -30,11 +30,10 @@ func (ctx *InsertCtx) Reset(rowsLen int) {
 		mr.MetricNameRaw = nil
 	}
 	ctx.mrs = ctx.mrs[:0]
-
 	if n := rowsLen - cap(ctx.mrs); n > 0 {
 		ctx.mrs = append(ctx.mrs[:cap(ctx.mrs)], make([]storage.MetricRow, n)...)
 	}
-	ctx.mrs = ctx.mrs[:rowsLen]
+	ctx.mrs = ctx.mrs[:0]
 	ctx.metricNamesBuf = ctx.metricNamesBuf[:0]
 }
 

app/vminsert/common/lines_reader.go

@@ -0,0 +1,68 @@
+package common
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
+)
+
+// The maximum size of a single line returned by ReadLinesBlock.
+const maxLineSize = 256 * 1024
+
+// Default size in bytes of a single block returned by ReadLinesBlock.
+const defaultBlockSize = 64 * 1024
+
+// ReadLinesBlock reads a block of lines delimited by '\n' from tailBuf and r into dstBuf.
+//
+// Trailing chars after the last newline are put into tailBuf.
+//
+// Returns (dstBuf, tailBuf).
+func ReadLinesBlock(r io.Reader, dstBuf, tailBuf []byte) ([]byte, []byte, error) {
+	if cap(dstBuf) < defaultBlockSize {
+		dstBuf = bytesutil.Resize(dstBuf, defaultBlockSize)
+	}
+	dstBuf = append(dstBuf[:0], tailBuf...)
+	tailBuf = tailBuf[:0]
+again:
+	n, err := r.Read(dstBuf[len(dstBuf):cap(dstBuf)])
+	// Check for error only if zero bytes read from r, i.e. no forward progress made.
+	// Otherwise process the read data.
+	if n == 0 {
+		if err == nil {
+			return dstBuf, tailBuf, fmt.Errorf("no forward progress made")
+		}
+		if err == io.EOF && len(dstBuf) > 0 {
+			// Missing newline in the end of stream. This is OK,
+			// so suppress io.EOF for now. It will be returned during the next
+			// call to ReadLinesBlock.
+			// This fixes https://github.com/VictoriaMetrics/VictoriaMetrics/issues/60 .
+			return dstBuf, tailBuf, nil
+		}
+		return dstBuf, tailBuf, err
+	}
+	dstBuf = dstBuf[:len(dstBuf)+n]
+
+	// Search for the last newline in dstBuf and put the rest into tailBuf.
+	nn := bytes.LastIndexByte(dstBuf[len(dstBuf)-n:], '\n')
+	if nn < 0 {
+		// Didn't found at least a single line.
+		if len(dstBuf) > maxLineSize {
+			return dstBuf, tailBuf, fmt.Errorf("too long line: more than %d bytes", maxLineSize)
+		}
+		if cap(dstBuf) < 2*len(dstBuf) {
+			// Increase dsbBuf capacity, so more data could be read into it.
+			dstBufLen := len(dstBuf)
+			dstBuf = bytesutil.Resize(dstBuf, 2*cap(dstBuf))
+			dstBuf = dstBuf[:dstBufLen]
+		}
+		goto again
+	}
+
+	// Found at least a single line. Return it.
+	nn += len(dstBuf) - n
+	tailBuf = append(tailBuf[:0], dstBuf[nn+1:]...)
+	dstBuf = dstBuf[:nn]
+	return dstBuf, tailBuf, nil
+}

app/vminsert/common/lines_reader_test.go

@@ -0,0 +1,213 @@
+package common
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"reflect"
+	"testing"
+)
+
+func TestReadLinesBlockFailure(t *testing.T) {
+	f := func(s string) {
+		t.Helper()
+		r := bytes.NewBufferString(s)
+		if _, _, err := ReadLinesBlock(r, nil, nil); err == nil {
+			t.Fatalf("expecting non-nil error")
+		}
+		sbr := &singleByteReader{
+			b: []byte(s),
+		}
+		if _, _, err := ReadLinesBlock(sbr, nil, nil); err == nil {
+			t.Fatalf("expecting non-nil error")
+		}
+		fr := &failureReader{}
+		if _, _, err := ReadLinesBlock(fr, nil, nil); err == nil {
+			t.Fatalf("expecting non-nil error")
+		}
+	}
+
+	// empty string
+	f("")
+
+	// too long string
+	b := make([]byte, maxLineSize+1)
+	f(string(b))
+}
+
+type failureReader struct{}
+
+func (fr *failureReader) Read(p []byte) (int, error) {
+	return 0, fmt.Errorf("some error")
+}
+
+func TestReadLinesBlockMultiLinesSingleByteReader(t *testing.T) {
+	f := func(s string, linesExpected []string) {
+		t.Helper()
+
+		r := &singleByteReader{
+			b: []byte(s),
+		}
+		var err error
+		var dstBuf, tailBuf []byte
+		var lines []string
+		for {
+			dstBuf, tailBuf, err = ReadLinesBlock(r, dstBuf, tailBuf)
+			if err != nil {
+				if err == io.EOF {
+					break
+				}
+				t.Fatalf("unexpected error in ReadLinesBlock(%q): %s", s, err)
+			}
+			lines = append(lines, string(dstBuf))
+		}
+		if !reflect.DeepEqual(lines, linesExpected) {
+			t.Fatalf("unexpected lines after reading %q: got %q; want %q", s, lines, linesExpected)
+		}
+	}
+
+	f("", nil)
+	f("foo", []string{"foo"})
+	f("foo\n", []string{"foo"})
+	f("foo\nbar", []string{"foo", "bar"})
+	f("\nfoo\nbar", []string{"", "foo", "bar"})
+	f("\nfoo\nbar\n", []string{"", "foo", "bar"})
+	f("\nfoo\nbar\n\n", []string{"", "foo", "bar", ""})
+}
+
+func TestReadLinesBlockMultiLinesBytesBuffer(t *testing.T) {
+	f := func(s string, linesExpected []string) {
+		t.Helper()
+
+		r := bytes.NewBufferString(s)
+		var err error
+		var dstBuf, tailBuf []byte
+		var lines []string
+		for {
+			dstBuf, tailBuf, err = ReadLinesBlock(r, dstBuf, tailBuf)
+			if err != nil {
+				if err == io.EOF {
+					break
+				}
+				t.Fatalf("unexpected error in ReadLinesBlock(%q): %s", s, err)
+			}
+			lines = append(lines, string(dstBuf))
+		}
+		if !reflect.DeepEqual(lines, linesExpected) {
+			t.Fatalf("unexpected lines after reading %q: got %q; want %q", s, lines, linesExpected)
+		}
+	}
+
+	f("", nil)
+	f("foo", []string{"foo"})
+	f("foo\n", []string{"foo"})
+	f("foo\nbar", []string{"foo", "bar"})
+	f("\nfoo\nbar", []string{"\nfoo", "bar"})
+	f("\nfoo\nbar\n", []string{"\nfoo\nbar"})
+	f("\nfoo\nbar\n\n", []string{"\nfoo\nbar\n"})
+}
+
+func TestReadLinesBlockSuccessSingleByteReader(t *testing.T) {
+	f := func(s, dstBufExpected, tailBufExpected string) {
+		t.Helper()
+
+		r := &singleByteReader{
+			b: []byte(s),
+		}
+		dstBuf, tailBuf, err := ReadLinesBlock(r, nil, nil)
+		if err != nil {
+			t.Fatalf("unexpected error: %s", err)
+		}
+		if string(dstBuf) != dstBufExpected {
+			t.Fatalf("unexpected dstBuf; got %q; want %q; tailBuf=%q", dstBuf, dstBufExpected, tailBuf)
+		}
+		if string(tailBuf) != tailBufExpected {
+			t.Fatalf("unexpected tailBuf; got %q; want %q; dstBuf=%q", tailBuf, tailBufExpected, dstBuf)
+		}
+
+		// Verify the same with non-empty dstBuf and tailBuf
+		r = &singleByteReader{
+			b: []byte(s),
+		}
+		dstBuf, tailBuf, err = ReadLinesBlock(r, dstBuf, tailBuf[:0])
+		if err != nil {
+			t.Fatalf("non-empty bufs: unexpected error: %s", err)
+		}
+		if string(dstBuf) != dstBufExpected {
+			t.Fatalf("non-empty bufs: unexpected dstBuf; got %q; want %q; tailBuf=%q", dstBuf, dstBufExpected, tailBuf)
+		}
+		if string(tailBuf) != tailBufExpected {
+			t.Fatalf("non-empty bufs: unexpected tailBuf; got %q; want %q; dstBuf=%q", tailBuf, tailBufExpected, dstBuf)
+		}
+	}
+
+	f("\n", "", "")
+	f("foo\n", "foo", "")
+	f("\nfoo", "", "")
+	f("foo\nbar", "foo", "")
+	f("foo\nbar\nbaz", "foo", "")
+	f("foo", "foo", "")
+
+	// The maximum line size
+	b := make([]byte, maxLineSize+10)
+	b[maxLineSize] = '\n'
+	f(string(b), string(b[:maxLineSize]), "")
+}
+
+func TestReadLinesBlockSuccessBytesBuffer(t *testing.T) {
+	f := func(s, dstBufExpected, tailBufExpected string) {
+		t.Helper()
+
+		r := bytes.NewBufferString(s)
+		dstBuf, tailBuf, err := ReadLinesBlock(r, nil, nil)
+		if err != nil {
+			t.Fatalf("unexpected error: %s", err)
+		}
+		if string(dstBuf) != dstBufExpected {
+			t.Fatalf("unexpected dstBuf; got %q; want %q; tailBuf=%q", dstBuf, dstBufExpected, tailBuf)
+		}
+		if string(tailBuf) != tailBufExpected {
+			t.Fatalf("unexpected tailBuf; got %q; want %q; dstBuf=%q", tailBuf, tailBufExpected, dstBuf)
+		}
+
+		// Verify the same with non-empty dstBuf and tailBuf
+		r = bytes.NewBufferString(s)
+		dstBuf, tailBuf, err = ReadLinesBlock(r, dstBuf, tailBuf[:0])
+		if err != nil {
+			t.Fatalf("non-empty bufs: unexpected error: %s", err)
+		}
+		if string(dstBuf) != dstBufExpected {
+			t.Fatalf("non-empty bufs: unexpected dstBuf; got %q; want %q; tailBuf=%q", dstBuf, dstBufExpected, tailBuf)
+		}
+		if string(tailBuf) != tailBufExpected {
+			t.Fatalf("non-empty bufs: unexpected tailBuf; got %q; want %q; dstBuf=%q", tailBuf, tailBufExpected, dstBuf)
+		}
+	}
+
+	f("\n", "", "")
+	f("foo\n", "foo", "")
+	f("\nfoo", "", "foo")
+	f("foo\nbar", "foo", "bar")
+	f("foo\nbar\nbaz", "foo\nbar", "baz")
+
+	// The maximum line size
+	b := make([]byte, maxLineSize+10)
+	b[maxLineSize] = '\n'
+	f(string(b), string(b[:maxLineSize]), string(b[maxLineSize+1:]))
+}
+
+type singleByteReader struct {
+	b []byte
+}
+
+func (sbr *singleByteReader) Read(p []byte) (int, error) {
+	if len(sbr.b) == 0 {
+		return 0, io.EOF
+	}
+	n := copy(p, sbr.b[:1])
+	sbr.b = sbr.b[n:]
+	if len(sbr.b) == 0 {
+		return n, io.EOF
+	}
+	return n, nil
+}

app/vminsert/concurrencylimiter/concurrencylimiter.go

@@ -1,34 +1,49 @@
 package concurrencylimiter
 
 import (
+	"flag"
 	"fmt"
 	"runtime"
 	"time"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/timerpool"
+	"github.com/VictoriaMetrics/metrics"
 )
 
+var maxConcurrentInserts = flag.Int("maxConcurrentInserts", runtime.GOMAXPROCS(-1)*4, "The maximum number of concurrent inserts")
+
 var (
-	// ch is the channel for limiting concurrent inserts.
-	// Put an item into it before performing an insert and remove
-	// the item after the insert is complete.
-	ch = make(chan struct{}, runtime.GOMAXPROCS(-1)*2)
+	// ch is the channel for limiting concurrent calls to Do.
+	ch chan struct{}
 
 	// waitDuration is the amount of time to wait until at least a single
-	// concurrent insert out of cap(Ch) inserts is complete.
+	// concurrent Do call out of cap(ch) inserts is complete.
 	waitDuration = time.Second * 30
 )
 
+// Init initializes concurrencylimiter.
+//
+// Init must be called after flag.Parse call.
+func Init() {
+	ch = make(chan struct{}, *maxConcurrentInserts)
+}
+
 // Do calls f with the limited concurrency.
 func Do(f func() error) error {
-	// Limit the number of conurrent inserts in order to prevent from excess
+	// Limit the number of conurrent f calls in order to prevent from excess
 	// memory usage and CPU trashing.
-	t := time.NewTimer(waitDuration)
+	t := timerpool.Get(waitDuration)
 	select {
 	case ch <- struct{}{}:
-		t.Stop()
+		timerpool.Put(t)
 		err := f()
 		<-ch
 		return err
 	case <-t.C:
-		return fmt.Errorf("the server is overloaded with %d concurrent inserts; either increase the number of CPUs or reduce the load", cap(ch))
+		timerpool.Put(t)
+		concurrencyLimitErrors.Inc()
+		return fmt.Errorf("the server is overloaded with %d concurrent inserts; either increase -maxConcurrentInserts or reduce the load", cap(ch))
 	}
 }
+
+var concurrencyLimitErrors = metrics.NewCounter(`vm_concurrency_limit_errors_total`)

app/vminsert/graphite/parser.go

@@ -86,7 +86,9 @@ func (r *Row) unmarshal(s string, tagsPool []Tag) ([]Tag, error) {
 
 	n = strings.IndexByte(tail, ' ')
 	if n < 0 {
-		return tagsPool, fmt.Errorf("cannot find whitespace between value and timestamp in %q", s)
+		// There is no timestamp. Use default timestamp instead.
+		r.Value = fastfloat.ParseBestEffort(tail)
+		return tagsPool, nil
 	}
 	r.Value = fastfloat.ParseBestEffort(tail[:n])
 	r.Timestamp = fastfloat.ParseInt64BestEffort(tail[n+1:])

app/vminsert/graphite/parser_test.go

@@ -22,9 +22,6 @@ func TestRowsUnmarshalFailure(t *testing.T) {
 	// Missing value
 	f("aaa")
 
-	// Missing timestamp
-	f("aaa 1123")
-
 	// Invalid multiline
 	f("aaa\nbbb 123 34")
 
@@ -81,6 +78,14 @@ func TestRowsUnmarshalSuccess(t *testing.T) {
 		}},
 	})
 
+	// Missing timestamp
+	f("aaa 1123", &Rows{
+		Rows: []Row{{
+			Metric: "aaa",
+			Value:  1123,
+		}},
+	})
+
 	// Tags
 	f("foo;bar=baz 1 2", &Rows{
 		Rows: []Row{{
@@ -116,13 +121,17 @@ func TestRowsUnmarshalSuccess(t *testing.T) {
 	})
 
 	// Multi lines
-	f("foo 0.3 2\nbar.baz 0.34 43\n", &Rows{
+	f("foo 0.3 2\naaa 3\nbar.baz 0.34 43\n", &Rows{
 		Rows: []Row{
 			{
 				Metric:    "foo",
 				Value:     0.3,
 				Timestamp: 2,
 			},
+			{
+				Metric: "aaa",
+				Value:  3,
+			},
 			{
 				Metric:    "bar.baz",
 				Value:     0.34,

app/vminsert/graphite/request_handler.go

@@ -1,7 +1,6 @@
 package graphite
 
 import (
-	"bytes"
 	"fmt"
 	"io"
 	"net"
@@ -55,8 +54,6 @@ func (ctx *pushCtx) InsertRows() error {
 	return ic.FlushBufs()
 }
 
-const maxReadPacketSize = 4 * 1024 * 1024
-
 const flushTimeout = 3 * time.Second
 
 func (ctx *pushCtx) Read(r io.Reader) bool {
@@ -71,40 +68,40 @@ func (ctx *pushCtx) Read(r io.Reader) bool {
 			return false
 		}
 	}
-	lr := io.LimitReader(r, maxReadPacketSize)
-	ctx.reqBuf.Reset()
-	ctx.reqBuf.B = append(ctx.reqBuf.B[:0], ctx.tailBuf...)
-	n, err := io.CopyBuffer(&ctx.reqBuf, lr, ctx.copyBuf[:])
-	if err != nil {
-		if ne, ok := err.(net.Error); ok && ne.Timeout() {
+	ctx.reqBuf, ctx.tailBuf, ctx.err = common.ReadLinesBlock(r, ctx.reqBuf, ctx.tailBuf)
+	if ctx.err != nil {
+		if ne, ok := ctx.err.(net.Error); ok && ne.Timeout() {
 			// Flush the read data on timeout and try reading again.
+			ctx.err = nil
 		} else {
-			graphiteReadErrors.Inc()
-			ctx.err = fmt.Errorf("cannot read graphite plaintext protocol data: %s", err)
+			if ctx.err != io.EOF {
+				graphiteReadErrors.Inc()
+				ctx.err = fmt.Errorf("cannot read graphite plaintext protocol data: %s", ctx.err)
+			}
 			return false
 		}
-	} else if n < maxReadPacketSize {
-		// Mark the end of stream.
-		ctx.err = io.EOF
 	}
-
-	// Parse all the rows until the last newline in ctx.reqBuf.B
-	nn := bytes.LastIndexByte(ctx.reqBuf.B, '\n')
-	ctx.tailBuf = ctx.tailBuf[:0]
-	if nn >= 0 {
-		ctx.tailBuf = append(ctx.tailBuf[:0], ctx.reqBuf.B[nn+1:]...)
-		ctx.reqBuf.B = ctx.reqBuf.B[:nn]
-	}
-	if err = ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf.B)); err != nil {
+	if err := ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf)); err != nil {
 		graphiteUnmarshalErrors.Inc()
-		ctx.err = fmt.Errorf("cannot unmarshal graphite plaintext protocol data with size %d: %s", len(ctx.reqBuf.B), err)
+		ctx.err = fmt.Errorf("cannot unmarshal graphite plaintext protocol data with size %d: %s", len(ctx.reqBuf), err)
 		return false
 	}
 
-	// Convert timestamps from seconds to milliseconds
-	for i := range ctx.Rows.Rows {
-		ctx.Rows.Rows[i].Timestamp *= 1e3
+	// Fill missing timestamps with the current timestamp rounded to seconds.
+	currentTimestamp := time.Now().Unix()
+	rows := ctx.Rows.Rows
+	for i := range rows {
+		r := &rows[i]
+		if r.Timestamp == 0 {
+			r.Timestamp = currentTimestamp
+		}
 	}
+
+	// Convert timestamps from seconds to milliseconds.
+	for i := range rows {
+		rows[i].Timestamp *= 1e3
+	}
+
 	return true
 }
 
@@ -112,9 +109,8 @@ type pushCtx struct {
 	Rows   Rows
 	Common common.InsertCtx
 
-	reqBuf  bytesutil.ByteBuffer
+	reqBuf  []byte
 	tailBuf []byte
-	copyBuf [16 * 1024]byte
 
 	err error
 }
@@ -129,7 +125,7 @@ func (ctx *pushCtx) Error() error {
 func (ctx *pushCtx) reset() {
 	ctx.Rows.Reset()
 	ctx.Common.Reset(0)
-	ctx.reqBuf.Reset()
+	ctx.reqBuf = ctx.reqBuf[:0]
 	ctx.tailBuf = ctx.tailBuf[:0]
 
 	ctx.err = nil

app/vminsert/influx/parser.go

@@ -293,8 +293,10 @@ func parseFieldValue(s string, hasQuotedFields bool) (float64, error) {
 		if len(s) < 2 || s[len(s)-1] != '"' {
 			return 0, fmt.Errorf("missing closing quote for quoted field value %s", s)
 		}
-		// Quoted string is translated to empty value.
-		return 0, nil
+		// Try converting quoted string to number, since sometimes Influx agents
+		// send numbers as strings.
+		s = s[1 : len(s)-1]
+		return fastfloat.ParseBestEffort(s), nil
 	}
 	ch := s[len(s)-1]
 	if ch == 'i' {

app/vminsert/influx/parser_test.go

@@ -241,17 +241,27 @@ func TestRowsUnmarshalSuccess(t *testing.T) {
 	})
 
 	// Line with multiple tags, multiple fields and timestamp
-	f(`system,host=ip-172-16-10-144 uptime_format="3 days, 21:01" 1557761040000000000`, &Rows{
+	f(`system,host=ip-172-16-10-144 uptime_format="3 days, 21:01",quoted_float="-1.23",quoted_int="123" 1557761040000000000`, &Rows{
 		Rows: []Row{{
 			Measurement: "system",
 			Tags: []Tag{{
 				Key:   "host",
 				Value: "ip-172-16-10-144",
 			}},
-			Fields: []Field{{
-				Key:   "uptime_format",
-				Value: 0,
-			}},
+			Fields: []Field{
+				{
+					Key:   "uptime_format",
+					Value: 0,
+				},
+				{
+					Key:   "quoted_float",
+					Value: -1.23,
+				},
+				{
+					Key:   "quoted_int",
+					Value: 123,
+				},
+			},
 			Timestamp: 1557761040000000000,
 		}},
 	})
@@ -338,4 +348,30 @@ func TestRowsUnmarshalSuccess(t *testing.T) {
 			},
 		},
 	})
+	// No newline after the second line.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/82
+	f("foo,tag=xyz field=1.23 48934\n"+
+		"bar x=-1i", &Rows{
+		Rows: []Row{
+			{
+				Measurement: "foo",
+				Tags: []Tag{{
+					Key:   "tag",
+					Value: "xyz",
+				}},
+				Fields: []Field{{
+					Key:   "field",
+					Value: 1.23,
+				}},
+				Timestamp: 48934,
+			},
+			{
+				Measurement: "bar",
+				Fields: []Field{{
+					Key:   "x",
+					Value: -1,
+				}},
+			},
+		},
+	})
 }

app/vminsert/influx/request_handler.go

@@ -1,8 +1,8 @@
 package influx
 
 import (
-	"bytes"
 	"compress/gzip"
+	"flag"
 	"fmt"
 	"io"
 	"net/http"
@@ -17,6 +17,11 @@ import (
 	"github.com/VictoriaMetrics/metrics"
 )
 
+var (
+	measurementFieldSeparator = flag.String("influxMeasurementFieldSeparator", "_", "Separator for `{measurement}{separator}{field_name}` metric name when inserted via Influx line protocol")
+	skipSingleField           = flag.Bool("influxSkipSingleField", false, "Uses `{measurement}` instead of `{measurement}{separator}{field_name}` for metic name if Influx line contains only a single field")
+)
+
 var rowsInserted = metrics.NewCounter(`vm_rows_inserted_total{type="influx"}`)
 
 // InsertHandler processes remote write for influx line protocol.
@@ -89,11 +94,16 @@ func (ctx *pushCtx) InsertRows(db string) error {
 		}
 		ctx.metricNameBuf = storage.MarshalMetricNameRaw(ctx.metricNameBuf[:0], ic.Labels)
 		ctx.metricGroupBuf = append(ctx.metricGroupBuf[:0], r.Measurement...)
-		ctx.metricGroupBuf = append(ctx.metricGroupBuf, '.')
+		skipFieldKey := len(r.Fields) == 1 && *skipSingleField
+		if !skipFieldKey {
+			ctx.metricGroupBuf = append(ctx.metricGroupBuf, *measurementFieldSeparator...)
+		}
 		metricGroupPrefixLen := len(ctx.metricGroupBuf)
 		for j := range r.Fields {
 			f := &r.Fields[j]
-			ctx.metricGroupBuf = append(ctx.metricGroupBuf[:metricGroupPrefixLen], f.Key...)
+			if !skipFieldKey {
+				ctx.metricGroupBuf = append(ctx.metricGroupBuf[:metricGroupPrefixLen], f.Key...)
+			}
 			metricGroup := bytesutil.ToUnsafeString(ctx.metricGroupBuf)
 			ic.Labels = ic.Labels[:0]
 			ic.AddLabel("", metricGroup)
@@ -123,36 +133,21 @@ func putGzipReader(zr *gzip.Reader) {
 
 var gzipReaderPool sync.Pool
 
-const maxReadPacketSize = 4 * 1024 * 1024
-
 func (ctx *pushCtx) Read(r io.Reader, tsMultiplier int64) bool {
 	if ctx.err != nil {
 		return false
 	}
-	lr := io.LimitReader(r, maxReadPacketSize)
-	ctx.reqBuf.Reset()
-	ctx.reqBuf.B = append(ctx.reqBuf.B[:0], ctx.tailBuf...)
-	n, err := io.CopyBuffer(&ctx.reqBuf, lr, ctx.copyBuf[:])
-	if err != nil {
-		influxReadErrors.Inc()
-		ctx.err = fmt.Errorf("cannot read influx line protocol data: %s", err)
+	ctx.reqBuf, ctx.tailBuf, ctx.err = common.ReadLinesBlock(r, ctx.reqBuf, ctx.tailBuf)
+	if ctx.err != nil {
+		if ctx.err != io.EOF {
+			influxReadErrors.Inc()
+			ctx.err = fmt.Errorf("cannot read influx line protocol data: %s", ctx.err)
+		}
 		return false
 	}
-	if n < maxReadPacketSize {
-		// Mark the end of stream.
-		ctx.err = io.EOF
-	}
-
-	// Parse all the rows until the last newline in ctx.reqBuf.B
-	nn := bytes.LastIndexByte(ctx.reqBuf.B, '\n')
-	ctx.tailBuf = ctx.tailBuf[:0]
-	if nn >= 0 {
-		ctx.tailBuf = append(ctx.tailBuf[:0], ctx.reqBuf.B[nn+1:]...)
-		ctx.reqBuf.B = ctx.reqBuf.B[:nn]
-	}
-	if err = ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf.B)); err != nil {
+	if err := ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf)); err != nil {
 		influxUnmarshalErrors.Inc()
-		ctx.err = fmt.Errorf("cannot unmarshal influx line protocol data with size %d: %s", len(ctx.reqBuf.B), err)
+		ctx.err = fmt.Errorf("cannot unmarshal influx line protocol data with size %d: %s", len(ctx.reqBuf), err)
 		return false
 	}
 
@@ -191,9 +186,8 @@ type pushCtx struct {
 	Rows   Rows
 	Common common.InsertCtx
 
-	reqBuf         bytesutil.ByteBuffer
+	reqBuf         []byte
 	tailBuf        []byte
-	copyBuf        [16 * 1024]byte
 	metricNameBuf  []byte
 	metricGroupBuf []byte
 
@@ -211,7 +205,7 @@ func (ctx *pushCtx) reset() {
 	ctx.Rows.Reset()
 	ctx.Common.Reset(0)
 
-	ctx.reqBuf.Reset()
+	ctx.reqBuf = ctx.reqBuf[:0]
 	ctx.tailBuf = ctx.tailBuf[:0]
 	ctx.metricNameBuf = ctx.metricNameBuf[:0]
 	ctx.metricGroupBuf = ctx.metricGroupBuf[:0]

app/vminsert/main.go

@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"strings"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vminsert/concurrencylimiter"
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vminsert/graphite"
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vminsert/influx"
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vminsert/opentsdb"
@@ -22,6 +23,7 @@ var (
 
 // Init initializes vminsert.
 func Init() {
+	concurrencylimiter.Init()
 	if len(*graphiteListenAddr) > 0 {
 		go graphite.Serve(*graphiteListenAddr)
 	}
@@ -63,7 +65,8 @@ func RequestHandler(w http.ResponseWriter, r *http.Request) bool {
 		w.WriteHeader(http.StatusNoContent)
 		return true
 	case "/query":
-		// Emulate fake response for influx query
+		// Emulate fake response for influx query.
+		// This is required for TSBS benchmark.
 		influxQueryRequests.Inc()
 		fmt.Fprintf(w, `{"results":[{"series":[{"values":[]}]}]}`)
 		return true

app/vminsert/opentsdb/request_handler.go

@@ -1,7 +1,6 @@
 package opentsdb
 
 import (
-	"bytes"
 	"fmt"
 	"io"
 	"net"
@@ -55,8 +54,6 @@ func (ctx *pushCtx) InsertRows() error {
 	return ic.FlushBufs()
 }
 
-const maxReadPacketSize = 4 * 1024 * 1024
-
 const flushTimeout = 3 * time.Second
 
 func (ctx *pushCtx) Read(r io.Reader) bool {
@@ -71,33 +68,22 @@ func (ctx *pushCtx) Read(r io.Reader) bool {
 			return false
 		}
 	}
-	lr := io.LimitReader(r, maxReadPacketSize)
-	ctx.reqBuf.Reset()
-	ctx.reqBuf.B = append(ctx.reqBuf.B[:0], ctx.tailBuf...)
-	n, err := io.CopyBuffer(&ctx.reqBuf, lr, ctx.copyBuf[:])
-	if err != nil {
-		if ne, ok := err.(net.Error); ok && ne.Timeout() {
+	ctx.reqBuf, ctx.tailBuf, ctx.err = common.ReadLinesBlock(r, ctx.reqBuf, ctx.tailBuf)
+	if ctx.err != nil {
+		if ne, ok := ctx.err.(net.Error); ok && ne.Timeout() {
 			// Flush the read data on timeout and try reading again.
+			ctx.err = nil
 		} else {
-			opentsdbReadErrors.Inc()
-			ctx.err = fmt.Errorf("cannot read OpenTSDB put protocol data: %s", err)
+			if ctx.err != io.EOF {
+				opentsdbReadErrors.Inc()
+				ctx.err = fmt.Errorf("cannot read OpenTSDB put protocol data: %s", ctx.err)
+			}
 			return false
 		}
-	} else if n < maxReadPacketSize {
-		// Mark the end of stream.
-		ctx.err = io.EOF
 	}
-
-	// Parse all the rows until the last newline in ctx.reqBuf.B
-	nn := bytes.LastIndexByte(ctx.reqBuf.B, '\n')
-	ctx.tailBuf = ctx.tailBuf[:0]
-	if nn >= 0 {
-		ctx.tailBuf = append(ctx.tailBuf[:0], ctx.reqBuf.B[nn+1:]...)
-		ctx.reqBuf.B = ctx.reqBuf.B[:nn]
-	}
-	if err = ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf.B)); err != nil {
+	if err := ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf)); err != nil {
 		opentsdbUnmarshalErrors.Inc()
-		ctx.err = fmt.Errorf("cannot unmarshal OpenTSDB put protocol data with size %d: %s", len(ctx.reqBuf.B), err)
+		ctx.err = fmt.Errorf("cannot unmarshal OpenTSDB put protocol data with size %d: %s", len(ctx.reqBuf), err)
 		return false
 	}
 
@@ -112,9 +98,8 @@ type pushCtx struct {
 	Rows   Rows
 	Common common.InsertCtx
 
-	reqBuf  bytesutil.ByteBuffer
+	reqBuf  []byte
 	tailBuf []byte
-	copyBuf [16 * 1024]byte
 
 	err error
 }
@@ -129,7 +114,7 @@ func (ctx *pushCtx) Error() error {
 func (ctx *pushCtx) reset() {
 	ctx.Rows.Reset()
 	ctx.Common.Reset(0)
-	ctx.reqBuf.Reset()
+	ctx.reqBuf = ctx.reqBuf[:0]
 	ctx.tailBuf = ctx.tailBuf[:0]
 
 	ctx.err = nil

app/vmselect/main.go

@@ -14,6 +14,7 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fs"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/httpserver"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/timerpool"
 	"github.com/VictoriaMetrics/metrics"
 )
 
@@ -42,13 +43,14 @@ func Stop() {
 // RequestHandler handles remote read API requests for Prometheus
 func RequestHandler(w http.ResponseWriter, r *http.Request) bool {
 	// Limit the number of concurrent queries.
-	// Sleep for a second until giving up. This should resolve short bursts in requests.
-	t := time.NewTimer(*maxQueueDuration)
+	// Sleep for a while until giving up. This should resolve short bursts in requests.
+	t := timerpool.Get(*maxQueueDuration)
 	select {
 	case concurrencyCh <- struct{}{}:
-		t.Stop()
+		timerpool.Put(t)
 		defer func() { <-concurrencyCh }()
 	case <-t.C:
+		timerpool.Put(t)
 		httpserver.Errorf(w, "cannot handle more than %d concurrent requests", cap(concurrencyCh))
 		return true
 	}
@@ -115,6 +117,15 @@ func RequestHandler(w http.ResponseWriter, r *http.Request) bool {
 			return true
 		}
 		return true
+	case "/api/v1/labels/count":
+		labelsCountRequests.Inc()
+		httpserver.EnableCORS(w, r)
+		if err := prometheus.LabelsCountHandler(w, r); err != nil {
+			labelsCountErrors.Inc()
+			sendPrometheusError(w, r, err)
+			return true
+		}
+		return true
 	case "/api/v1/export":
 		exportRequests.Inc()
 		if err := prometheus.ExportHandler(w, r); err != nil {
@@ -178,6 +189,9 @@ var (
 	labelsRequests = metrics.NewCounter(`vm_http_requests_total{path="/api/v1/labels"}`)
 	labelsErrors   = metrics.NewCounter(`vm_http_request_errors_total{path="/api/v1/labels"}`)
 
+	labelsCountRequests = metrics.NewCounter(`vm_http_requests_total{path="/api/v1/labels/count"}`)
+	labelsCountErrors   = metrics.NewCounter(`vm_http_request_errors_total{path="/api/v1/labels/count"}`)
+
 	deleteRequests = metrics.NewCounter(`vm_http_requests_total{path="/api/v1/admin/tsdb/delete_series"}`)
 	deleteErrors   = metrics.NewCounter(`vm_http_request_errors_total{path="/api/v1/admin/tsdb/delete_series"}`)
 

app/vmselect/netstorage/netstorage.go

@@ -400,6 +400,36 @@ func GetLabelValues(labelName string, deadline Deadline) ([]string, error) {
 	return labelValues, nil
 }
 
+// GetLabelEntries returns all the label entries until the given deadline.
+func GetLabelEntries(deadline Deadline) ([]storage.TagEntry, error) {
+	labelEntries, err := vmstorage.SearchTagEntries(*maxTagKeysPerSearch, *maxTagValuesPerSearch)
+	if err != nil {
+		return nil, fmt.Errorf("error during label entries request: %s", err)
+	}
+
+	// Substitute "" with "__name__"
+	for i := range labelEntries {
+		e := &labelEntries[i]
+		if e.Key == "" {
+			e.Key = "__name__"
+		}
+	}
+
+	// Sort labelEntries by the number of label values in each entry.
+	sort.Slice(labelEntries, func(i, j int) bool {
+		a, b := labelEntries[i].Values, labelEntries[j].Values
+		if len(a) < len(b) {
+			return true
+		}
+		if len(a) > len(b) {
+			return false
+		}
+		return labelEntries[i].Key < labelEntries[j].Key
+	})
+
+	return labelEntries, nil
+}
+
 // GetSeriesCount returns the number of unique series.
 func GetSeriesCount(deadline Deadline) (uint64, error) {
 	n, err := vmstorage.GetSeriesCount()

app/vmselect/netstorage/tmp_blocks_file.go

@@ -22,9 +22,7 @@ func InitTmpBlocksDir(tmpDirPath string) {
 		tmpDirPath = os.TempDir()
 	}
 	tmpBlocksDir = tmpDirPath + "/searchResults"
-	if err := os.RemoveAll(tmpBlocksDir); err != nil {
-		logger.Panicf("FATAL: cannot remove %q: %s", tmpBlocksDir, err)
-	}
+	fs.MustRemoveAll(tmpBlocksDir)
 	if err := fs.MkdirAllIfNotExist(tmpBlocksDir); err != nil {
 		logger.Panicf("FATAL: cannot create %q: %s", tmpBlocksDir, err)
 	}

app/vmselect/prometheus/labels_count_response.qtpl

@@ -0,0 +1,17 @@
+{% import "github.com/VictoriaMetrics/VictoriaMetrics/lib/storage" %}
+
+{% stripspace %}
+LabelsCountResponse generates response for /api/v1/labels/count .
+{% func LabelsCountResponse(labelEntries []storage.TagEntry) %}
+{
+	"status":"success",
+	"data":{
+		{% for i, e := range labelEntries %}
+			{%q= e.Key %}:{%d= len(e.Values) %}
+			{% if i+1 < len(labelEntries) %},{% endif %}
+		{% endfor %}
+	}
+}
+{% endfunc %}
+
+{% endstripspace %}

app/vmselect/prometheus/labels_count_response.qtpl.go

@@ -0,0 +1,74 @@
+// Code generated by qtc from "labels_count_response.qtpl". DO NOT EDIT.
+// See https://github.com/valyala/quicktemplate for details.
+
+//line app/vmselect/prometheus/labels_count_response.qtpl:1
+package prometheus
+
+//line app/vmselect/prometheus/labels_count_response.qtpl:1
+import "github.com/VictoriaMetrics/VictoriaMetrics/lib/storage"
+
+// LabelsCountResponse generates response for /api/v1/labels/count .
+
+//line app/vmselect/prometheus/labels_count_response.qtpl:5
+import (
+	qtio422016 "io"
+
+	qt422016 "github.com/valyala/quicktemplate"
+)
+
+//line app/vmselect/prometheus/labels_count_response.qtpl:5
+var (
+	_ = qtio422016.Copy
+	_ = qt422016.AcquireByteBuffer
+)
+
+//line app/vmselect/prometheus/labels_count_response.qtpl:5
+func StreamLabelsCountResponse(qw422016 *qt422016.Writer, labelEntries []storage.TagEntry) {
+//line app/vmselect/prometheus/labels_count_response.qtpl:5
+	qw422016.N().S(`{"status":"success","data":{`)
+//line app/vmselect/prometheus/labels_count_response.qtpl:9
+	for i, e := range labelEntries {
+//line app/vmselect/prometheus/labels_count_response.qtpl:10
+		qw422016.N().Q(e.Key)
+//line app/vmselect/prometheus/labels_count_response.qtpl:10
+		qw422016.N().S(`:`)
+//line app/vmselect/prometheus/labels_count_response.qtpl:10
+		qw422016.N().D(len(e.Values))
+//line app/vmselect/prometheus/labels_count_response.qtpl:11
+		if i+1 < len(labelEntries) {
+//line app/vmselect/prometheus/labels_count_response.qtpl:11
+			qw422016.N().S(`,`)
+//line app/vmselect/prometheus/labels_count_response.qtpl:11
+		}
+//line app/vmselect/prometheus/labels_count_response.qtpl:12
+	}
+//line app/vmselect/prometheus/labels_count_response.qtpl:12
+	qw422016.N().S(`}}`)
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+}
+
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+func WriteLabelsCountResponse(qq422016 qtio422016.Writer, labelEntries []storage.TagEntry) {
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+	StreamLabelsCountResponse(qw422016, labelEntries)
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+}
+
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+func LabelsCountResponse(labelEntries []storage.TagEntry) string {
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+	WriteLabelsCountResponse(qb422016, labelEntries)
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+	qs422016 := string(qb422016.B)
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+	return qs422016
+//line app/vmselect/prometheus/labels_count_response.qtpl:15
+}

app/vmselect/prometheus/prometheus.go

@@ -37,9 +37,21 @@ func FederateHandler(w http.ResponseWriter, r *http.Request) error {
 		return fmt.Errorf("cannot parse request form values: %s", err)
 	}
 	matches := r.Form["match[]"]
-	maxLookback := getDuration(r, "max_lookback", defaultStep)
-	start := getTime(r, "start", ct-maxLookback)
-	end := getTime(r, "end", ct)
+	if len(matches) == 0 {
+		return fmt.Errorf("missing `match[]` arg")
+	}
+	maxLookback, err := getDuration(r, "max_lookback", defaultStep)
+	if err != nil {
+		return err
+	}
+	start, err := getTime(r, "start", ct-maxLookback)
+	if err != nil {
+		return err
+	}
+	end, err := getTime(r, "end", ct)
+	if err != nil {
+		return err
+	}
 	deadline := getDeadline(r)
 	if start >= end {
 		start = end - defaultStep
@@ -97,10 +109,19 @@ func ExportHandler(w http.ResponseWriter, r *http.Request) error {
 	if len(matches) == 0 {
 		// Maintain backwards compatibility
 		match := r.FormValue("match")
+		if len(match) == 0 {
+			return fmt.Errorf("missing `match[]` arg")
+		}
 		matches = []string{match}
 	}
-	start := getTime(r, "start", 0)
-	end := getTime(r, "end", ct)
+	start, err := getTime(r, "start", 0)
+	if err != nil {
+		return err
+	}
+	end, err := getTime(r, "end", ct)
+	if err != nil {
+		return err
+	}
 	format := r.FormValue("format")
 	deadline := getDeadline(r)
 	if start >= end {
@@ -156,6 +177,11 @@ func exportHandler(w http.ResponseWriter, matches []string, start, end int64, fo
 	w.Header().Set("Content-Type", contentType)
 	writeResponseFunc(w, resultsCh)
 
+	// Consume all the data from resultsCh in the event writeResponseFunc
+	// fails to consume all the data.
+	for bb := range resultsCh {
+		quicktemplate.ReleaseByteBuffer(bb)
+	}
 	err = <-doneCh
 	if err != nil {
 		return fmt.Errorf("error during data fetching: %s", err)
@@ -175,6 +201,9 @@ func DeleteHandler(r *http.Request) error {
 		return fmt.Errorf("start and end aren't supported. Remove these args from the query in order to delete all the matching metrics")
 	}
 	matches := r.Form["match[]"]
+	if len(matches) == 0 {
+		return fmt.Errorf("missing `match[]` arg")
+	}
 	tagFilterss, err := getTagFilterssFromMatches(matches)
 	if err != nil {
 		return err
@@ -214,6 +243,23 @@ func LabelValuesHandler(labelName string, w http.ResponseWriter, r *http.Request
 
 var labelValuesDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/api/v1/label/{}/values"}`)
 
+// LabelsCountHandler processes /api/v1/labels/count request.
+func LabelsCountHandler(w http.ResponseWriter, r *http.Request) error {
+	startTime := time.Now()
+	deadline := getDeadline(r)
+	labelEntries, err := netstorage.GetLabelEntries(deadline)
+	if err != nil {
+		return fmt.Errorf(`cannot obtain label entries: %s`, err)
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	WriteLabelsCountResponse(w, labelEntries)
+	labelsCountDuration.UpdateDuration(startTime)
+	return nil
+}
+
+var labelsCountDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/api/v1/labels/count"}`)
+
 // LabelsHandler processes /api/v1/labels request.
 //
 // See https://prometheus.io/docs/prometheus/latest/querying/api/#getting-label-names
@@ -260,8 +306,19 @@ func SeriesHandler(w http.ResponseWriter, r *http.Request) error {
 		return fmt.Errorf("cannot parse form values: %s", err)
 	}
 	matches := r.Form["match[]"]
-	start := getTime(r, "start", ct-defaultStep)
-	end := getTime(r, "end", ct)
+	if len(matches) == 0 {
+		return fmt.Errorf("missing `match[]` arg")
+	}
+	// Set start to minTimeMsecs by default as Prometheus does.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/91
+	start, err := getTime(r, "start", minTimeMsecs)
+	if err != nil {
+		return err
+	}
+	end, err := getTime(r, "end", ct)
+	if err != nil {
+		return err
+	}
 	deadline := getDeadline(r)
 
 	tagFilterss, err := getTagFilterssFromMatches(matches)
@@ -297,11 +354,10 @@ func SeriesHandler(w http.ResponseWriter, r *http.Request) error {
 	WriteSeriesResponse(w, resultsCh)
 
 	// Consume all the data from resultsCh in the event WriteSeriesResponse
-	// fail to consume all the data.
+	// fails to consume all the data.
 	for bb := range resultsCh {
 		quicktemplate.ReleaseByteBuffer(bb)
 	}
-
 	err = <-doneCh
 	if err != nil {
 		return fmt.Errorf("error during data fetching: %s", err)
@@ -320,8 +376,17 @@ func QueryHandler(w http.ResponseWriter, r *http.Request) error {
 	ct := currentTime()
 
 	query := r.FormValue("query")
-	start := getTime(r, "time", ct)
-	step := getDuration(r, "step", latencyOffset)
+	if len(query) == 0 {
+		return fmt.Errorf("missing `query` arg")
+	}
+	start, err := getTime(r, "time", ct)
+	if err != nil {
+		return err
+	}
+	step, err := getDuration(r, "step", latencyOffset)
+	if err != nil {
+		return err
+	}
 	deadline := getDeadline(r)
 
 	if len(query) > *maxQueryLen {
@@ -363,7 +428,7 @@ func QueryHandler(w http.ResponseWriter, r *http.Request) error {
 		Step:     step,
 		Deadline: deadline,
 	}
-	result, err := promql.Exec(&ec, query)
+	result, err := promql.Exec(&ec, query, true)
 	if err != nil {
 		return fmt.Errorf("cannot execute %q: %s", query, err)
 	}
@@ -384,9 +449,21 @@ func QueryRangeHandler(w http.ResponseWriter, r *http.Request) error {
 	ct := currentTime()
 
 	query := r.FormValue("query")
-	start := getTime(r, "start", ct-defaultStep)
-	end := getTime(r, "end", ct)
-	step := getDuration(r, "step", defaultStep)
+	if len(query) == 0 {
+		return fmt.Errorf("missing `query` arg")
+	}
+	start, err := getTime(r, "start", ct-defaultStep)
+	if err != nil {
+		return err
+	}
+	end, err := getTime(r, "end", ct)
+	if err != nil {
+		return err
+	}
+	step, err := getDuration(r, "step", defaultStep)
+	if err != nil {
+		return err
+	}
 	deadline := getDeadline(r)
 	mayCache := !getBool(r, "nocache")
 
@@ -409,12 +486,12 @@ func QueryRangeHandler(w http.ResponseWriter, r *http.Request) error {
 		Deadline: deadline,
 		MayCache: mayCache,
 	}
-	result, err := promql.Exec(&ec, query)
+	result, err := promql.Exec(&ec, query, false)
 	if err != nil {
 		return fmt.Errorf("cannot execute %q: %s", query, err)
 	}
 	if ct-end < latencyOffset {
-		adjustLastPoints(result)
+		result = adjustLastPoints(result)
 	}
 
 	w.Header().Set("Content-Type", "application/json")
@@ -427,17 +504,17 @@ var queryRangeDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/
 
 // adjustLastPoints substitutes the last point values with the previous
 // point values, since the last points may contain garbage.
-func adjustLastPoints(tss []netstorage.Result) {
+func adjustLastPoints(tss []netstorage.Result) []netstorage.Result {
 	if len(tss) == 0 {
-		return
+		return nil
 	}
 
 	// Search for the last non-NaN value across all the timeseries.
 	lastNonNaNIdx := -1
 	for i := range tss {
-		r := &tss[i]
-		j := len(r.Values) - 1
-		for j >= 0 && math.IsNaN(r.Values[j]) {
+		values := tss[i].Values
+		j := len(values) - 1
+		for j >= 0 && math.IsNaN(values[j]) {
 			j--
 		}
 		if j > lastNonNaNIdx {
@@ -446,75 +523,97 @@ func adjustLastPoints(tss []netstorage.Result) {
 	}
 	if lastNonNaNIdx == -1 {
 		// All timeseries contain only NaNs.
-		return
+		return nil
 	}
 
-	// Substitute last three values starting from lastNonNaNIdx
+	// Substitute the last two values starting from lastNonNaNIdx
 	// with the previous values for each timeseries.
 	for i := range tss {
-		r := &tss[i]
-		for j := 0; j < 3; j++ {
+		values := tss[i].Values
+		for j := 0; j < 2; j++ {
 			idx := lastNonNaNIdx + j
-			if idx <= 0 || idx >= len(r.Values) {
+			if idx <= 0 || idx >= len(values) || math.IsNaN(values[idx-1]) {
 				continue
 			}
-			r.Values[idx] = r.Values[idx-1]
+			values[idx] = values[idx-1]
 		}
 	}
+	return tss
 }
 
-func getTime(r *http.Request, argKey string, defaultValue int64) int64 {
+func getTime(r *http.Request, argKey string, defaultValue int64) (int64, error) {
 	argValue := r.FormValue(argKey)
 	if len(argValue) == 0 {
-		return defaultValue
+		return defaultValue, nil
 	}
 	secs, err := strconv.ParseFloat(argValue, 64)
 	if err != nil {
 		// Try parsing string format
 		t, err := time.Parse(time.RFC3339, argValue)
 		if err != nil {
-			return defaultValue
+			// Handle Prometheus'-provided minTime and maxTime.
+			// See https://github.com/prometheus/client_golang/issues/614
+			switch argValue {
+			case prometheusMinTimeFormatted:
+				return minTimeMsecs, nil
+			case prometheusMaxTimeFormatted:
+				return maxTimeMsecs, nil
+			}
+			return 0, fmt.Errorf("cannot parse %q=%q: %s", argKey, argValue, err)
 		}
 		secs = float64(t.UnixNano()) / 1e9
 	}
 	msecs := int64(secs * 1e3)
-	if msecs < minTimeMsecs || msecs > maxTimeMsecs {
-		return defaultValue
+	if msecs < minTimeMsecs {
+		msecs = 0
 	}
-	return msecs
+	if msecs > maxTimeMsecs {
+		msecs = maxTimeMsecs
+	}
+	return msecs, nil
 }
 
+var (
+	// These constants were obtained from https://github.com/prometheus/prometheus/blob/91d7175eaac18b00e370965f3a8186cc40bf9f55/web/api/v1/api.go#L442
+	// See https://github.com/prometheus/client_golang/issues/614 for details.
+	prometheusMinTimeFormatted = time.Unix(math.MinInt64/1000+62135596801, 0).UTC().Format(time.RFC3339Nano)
+	prometheusMaxTimeFormatted = time.Unix(math.MaxInt64/1000-62135596801, 999999999).UTC().Format(time.RFC3339Nano)
+)
+
 const (
 	// These values prevent from overflow when storing msec-precision time in int64.
-	minTimeMsecs = int64(-1<<63) / 1e6
+	minTimeMsecs = 0 // use 0 instead of `int64(-1<<63) / 1e6` because the storage engine doesn't actually support negative time
 	maxTimeMsecs = int64(1<<63-1) / 1e6
 )
 
-func getDuration(r *http.Request, argKey string, defaultValue int64) int64 {
+func getDuration(r *http.Request, argKey string, defaultValue int64) (int64, error) {
 	argValue := r.FormValue(argKey)
 	if len(argValue) == 0 {
-		return defaultValue
+		return defaultValue, nil
 	}
 	secs, err := strconv.ParseFloat(argValue, 64)
 	if err != nil {
 		// Try parsing string format
 		d, err := time.ParseDuration(argValue)
 		if err != nil {
-			return defaultValue
+			return 0, fmt.Errorf("cannot parse %q=%q: %s", argKey, argValue, err)
 		}
 		secs = d.Seconds()
 	}
 	msecs := int64(secs * 1e3)
 	if msecs <= 0 || msecs > maxDurationMsecs {
-		return defaultValue
+		return 0, fmt.Errorf("%q=%dms is out of allowed range [%d ... %d]", argKey, msecs, 0, int64(maxDurationMsecs))
 	}
-	return msecs
+	return msecs, nil
 }
 
 const maxDurationMsecs = 100 * 365 * 24 * 3600 * 1000
 
 func getDeadline(r *http.Request) netstorage.Deadline {
-	d := getDuration(r, "timeout", 0)
+	d, err := getDuration(r, "timeout", 0)
+	if err != nil {
+		d = 0
+	}
 	dMax := int64(maxQueryDuration.Seconds() * 1e3)
 	if d <= 0 || d > dMax {
 		d = dMax

app/vmselect/prometheus/prometheus_test.go

@@ -0,0 +1,78 @@
+package prometheus
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"testing"
+)
+
+func TestGetTimeSuccess(t *testing.T) {
+	f := func(s string, timestampExpected int64) {
+		t.Helper()
+		urlStr := fmt.Sprintf("http://foo.bar/baz?s=%s", url.QueryEscape(s))
+		r, err := http.NewRequest("GET", urlStr, nil)
+		if err != nil {
+			t.Fatalf("unexpected error in NewRequest: %s", err)
+		}
+
+		// Verify defaultValue
+		ts, err := getTime(r, "foo", 123)
+		if err != nil {
+			t.Fatalf("unexpected error when obtaining default time from getTime(%q): %s", s, err)
+		}
+		if ts != 123 {
+			t.Fatalf("unexpected default value for getTime(%q); got %d; want %d", s, ts, 123)
+		}
+
+		// Verify timestampExpected
+		ts, err = getTime(r, "s", 123)
+		if err != nil {
+			t.Fatalf("unexpected error in getTime(%q): %s", s, err)
+		}
+		if ts != timestampExpected {
+			t.Fatalf("unexpected timestamp for getTime(%q); got %d; want %d", s, ts, timestampExpected)
+		}
+	}
+
+	f("2019-07-07T20:01:02Z", 1562529662000)
+	f("2019-07-07T20:47:40+03:00", 1562521660000)
+	f("-292273086-05-16T16:47:06Z", minTimeMsecs)
+	f("292277025-08-18T07:12:54.999999999Z", maxTimeMsecs)
+	f("1562529662.324", 1562529662324)
+	f("-9223372036.854", minTimeMsecs)
+	f("-9223372036.855", minTimeMsecs)
+	f("9223372036.855", maxTimeMsecs)
+}
+
+func TestGetTimeError(t *testing.T) {
+	f := func(s string) {
+		t.Helper()
+		urlStr := fmt.Sprintf("http://foo.bar/baz?s=%s", url.QueryEscape(s))
+		r, err := http.NewRequest("GET", urlStr, nil)
+		if err != nil {
+			t.Fatalf("unexpected error in NewRequest: %s", err)
+		}
+
+		// Verify defaultValue
+		ts, err := getTime(r, "foo", 123)
+		if err != nil {
+			t.Fatalf("unexpected error when obtaining default time from getTime(%q): %s", s, err)
+		}
+		if ts != 123 {
+			t.Fatalf("unexpected default value for getTime(%q); got %d; want %d", s, ts, 123)
+		}
+
+		// Verify timestampExpected
+		_, err = getTime(r, "s", 123)
+		if err == nil {
+			t.Fatalf("expecting non-nil error in getTime(%q)", s)
+		}
+	}
+
+	f("foo")
+	f("2019-07-07T20:01:02Zisdf")
+	f("2019-07-07T20:47:40+03:00123")
+	f("-292273086-05-16T16:47:07Z")
+	f("292277025-08-18T07:12:54.999999998Z")
+}

app/vmselect/promql/aggr.go

@@ -6,6 +6,9 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/storage"
 )
 
 var aggrFuncs = map[string]aggrFunc{
@@ -26,6 +29,8 @@ var aggrFuncs = map[string]aggrFunc{
 	"median":   aggrFuncMedian,
 	"limitk":   aggrFuncLimitK,
 	"distinct": newAggrFunc(aggrFuncDistinct),
+	"sum2":     newAggrFunc(aggrFuncSum2),
+	"geomean":  newAggrFunc(aggrFuncGeomean),
 }
 
 type aggrFunc func(afa *aggrFuncArg) ([]*timeseries, error)
@@ -65,33 +70,26 @@ func newAggrFunc(afe func(tss []*timeseries) []*timeseries) aggrFunc {
 	}
 }
 
+func removeGroupTags(metricName *storage.MetricName, modifier *modifierExpr) {
+	groupOp := strings.ToLower(modifier.Op)
+	switch groupOp {
+	case "", "by":
+		metricName.RemoveTagsOn(modifier.Args)
+	case "without":
+		metricName.RemoveTagsIgnoring(modifier.Args)
+	default:
+		logger.Panicf("BUG: unknown group modifier: %q", groupOp)
+	}
+}
+
 func aggrFuncExt(afe func(tss []*timeseries) []*timeseries, argOrig []*timeseries, modifier *modifierExpr, keepOriginal bool) ([]*timeseries, error) {
 	arg := copyTimeseriesMetricNames(argOrig)
 
-	// Filter out superflouos tags.
-	var groupTags []string
-	groupOp := "by"
-	if modifier.Op != "" {
-		groupTags = modifier.Args
-		groupOp = strings.ToLower(modifier.Op)
-	}
-	switch groupOp {
-	case "by":
-		for _, ts := range arg {
-			ts.MetricName.RemoveTagsOn(groupTags)
-		}
-	case "without":
-		for _, ts := range arg {
-			ts.MetricName.RemoveTagsIgnoring(groupTags)
-		}
-	default:
-		return nil, fmt.Errorf(`unknown modifier: %q`, groupOp)
-	}
-
 	// Perform grouping.
 	m := make(map[string][]*timeseries)
 	bb := bbPool.Get()
 	for i, ts := range arg {
+		removeGroupTags(&ts.MetricName, modifier)
 		bb.B = marshalMetricNameSorted(bb.B[:0], &ts.MetricName)
 		if keepOriginal {
 			ts = argOrig[i]
@@ -100,10 +98,18 @@ func aggrFuncExt(afe func(tss []*timeseries) []*timeseries, argOrig []*timeserie
 	}
 	bbPool.Put(bb)
 
+	srcTssCount := 0
+	dstTssCount := 0
 	rvs := make([]*timeseries, 0, len(m))
 	for _, tss := range m {
 		rv := afe(tss)
 		rvs = append(rvs, rv...)
+		srcTssCount += len(tss)
+		dstTssCount += len(rv)
+		if dstTssCount > 2000 && dstTssCount > 16*srcTssCount {
+			// This looks like count_values explosion.
+			return nil, fmt.Errorf(`too many timeseries after aggragation; got %d; want less than %d`, dstTssCount, 16*srcTssCount)
+		}
 	}
 	return rvs, nil
 }
@@ -132,6 +138,52 @@ func aggrFuncSum(tss []*timeseries) []*timeseries {
 	return tss[:1]
 }
 
+func aggrFuncSum2(tss []*timeseries) []*timeseries {
+	dst := tss[0]
+	for i := range dst.Values {
+		sum2 := float64(0)
+		count := 0
+		for _, ts := range tss {
+			v := ts.Values[i]
+			if math.IsNaN(v) {
+				continue
+			}
+			sum2 += v * v
+			count++
+		}
+		if count == 0 {
+			sum2 = nan
+		}
+		dst.Values[i] = sum2
+	}
+	return tss[:1]
+}
+
+func aggrFuncGeomean(tss []*timeseries) []*timeseries {
+	if len(tss) == 1 {
+		// Fast path - nothing to geomean.
+		return tss
+	}
+	dst := tss[0]
+	for i := range dst.Values {
+		p := 1.0
+		count := 0
+		for _, ts := range tss {
+			v := ts.Values[i]
+			if math.IsNaN(v) {
+				continue
+			}
+			p *= v
+			count++
+		}
+		if count == 0 {
+			p = nan
+		}
+		dst.Values[i] = math.Pow(p, 1/float64(count))
+	}
+	return tss[:1]
+}
+
 func aggrFuncMin(tss []*timeseries) []*timeseries {
 	if len(tss) == 1 {
 		// Fast path - nothing to min.
@@ -301,6 +353,9 @@ func aggrFuncCountValues(afa *aggrFuncArg) ([]*timeseries, error) {
 		m := make(map[float64]bool)
 		for _, ts := range tss {
 			for _, v := range ts.Values {
+				if math.IsNaN(v) {
+					continue
+				}
 				m[v] = true
 			}
 		}
@@ -313,7 +368,7 @@ func aggrFuncCountValues(afa *aggrFuncArg) ([]*timeseries, error) {
 		var rvs []*timeseries
 		for _, v := range values {
 			var dst timeseries
-			dst.CopyFrom(tss[0])
+			dst.CopyFromShallowTimestamps(tss[0])
 			dst.MetricName.RemoveTag(dstLabel)
 			dst.MetricName.AddTag(dstLabel, strconv.FormatFloat(v, 'g', -1, 64))
 			for i := range dst.Values {
@@ -372,7 +427,7 @@ func newAggrFuncTopK(isReverse bool) aggrFunc {
 					ts.Values[n] = nan
 				}
 			}
-			return rvs
+			return removeNaNs(rvs)
 		}
 		return aggrFuncExt(afe, args[1], &afa.ae.Modifier, true)
 	}
@@ -457,6 +512,7 @@ func newAggrQuantileFunc(phis []float64) func(tss []*timeseries) []*timeseries {
 			idx := int(math.Round(float64(len(tss)-1) * phi))
 			dst.Values[n] = tss[idx].Values[n]
 		}
+		tss[0] = dst
 		return tss[:1]
 	}
 }

app/vmselect/promql/aggr_incremental.go

@@ -0,0 +1,270 @@
+package promql
+
+import (
+	"math"
+	"strings"
+	"sync"
+)
+
+// callbacks for optimized incremental calculations for aggregate functions
+// over rollups over metricExpr.
+//
+// These calculations save RAM for aggregates over big number of time series.
+var incrementalAggrFuncCallbacksMap = map[string]*incrementalAggrFuncCallbacks{
+	"sum": {
+		updateAggrFunc:   updateAggrSum,
+		finalizeAggrFunc: finalizeAggrCommon,
+	},
+	"min": {
+		updateAggrFunc:   updateAggrMin,
+		finalizeAggrFunc: finalizeAggrCommon,
+	},
+	"max": {
+		updateAggrFunc:   updateAggrMax,
+		finalizeAggrFunc: finalizeAggrCommon,
+	},
+	"avg": {
+		updateAggrFunc:   updateAggrAvg,
+		finalizeAggrFunc: finalizeAggrAvg,
+	},
+	"count": {
+		updateAggrFunc:   updateAggrCount,
+		finalizeAggrFunc: finalizeAggrCount,
+	},
+	"sum2": {
+		updateAggrFunc:   updateAggrSum2,
+		finalizeAggrFunc: finalizeAggrCommon,
+	},
+	"geomean": {
+		updateAggrFunc:   updateAggrGeomean,
+		finalizeAggrFunc: finalizeAggrGeomean,
+	},
+}
+
+type incrementalAggrFuncContext struct {
+	ae *aggrFuncExpr
+
+	mu sync.Mutex
+	m  map[string]*incrementalAggrContext
+
+	callbacks *incrementalAggrFuncCallbacks
+}
+
+func newIncrementalAggrFuncContext(ae *aggrFuncExpr, callbacks *incrementalAggrFuncCallbacks) *incrementalAggrFuncContext {
+	return &incrementalAggrFuncContext{
+		ae:        ae,
+		m:         make(map[string]*incrementalAggrContext, 1),
+		callbacks: callbacks,
+	}
+}
+
+func (iafc *incrementalAggrFuncContext) updateTimeseries(ts *timeseries) {
+	removeGroupTags(&ts.MetricName, &iafc.ae.Modifier)
+	bb := bbPool.Get()
+	bb.B = marshalMetricNameSorted(bb.B[:0], &ts.MetricName)
+	iafc.mu.Lock()
+	iac := iafc.m[string(bb.B)]
+	if iac == nil {
+		tsAggr := &timeseries{
+			Values:     make([]float64, len(ts.Values)),
+			Timestamps: ts.Timestamps,
+			denyReuse:  true,
+		}
+		tsAggr.MetricName.CopyFrom(&ts.MetricName)
+		iac = &incrementalAggrContext{
+			ts:     tsAggr,
+			values: make([]float64, len(ts.Values)),
+		}
+		iafc.m[string(bb.B)] = iac
+	}
+	iafc.callbacks.updateAggrFunc(iac, ts.Values)
+	iafc.mu.Unlock()
+	bbPool.Put(bb)
+}
+
+func (iafc *incrementalAggrFuncContext) finalizeTimeseries() []*timeseries {
+	// There is no need in iafc.mu.Lock here, since getTimeseries must be called
+	// without concurrent goroutines touching iafc.
+	tss := make([]*timeseries, 0, len(iafc.m))
+	finalizeAggrFunc := iafc.callbacks.finalizeAggrFunc
+	for _, iac := range iafc.m {
+		finalizeAggrFunc(iac)
+		tss = append(tss, iac.ts)
+	}
+	return tss
+}
+
+type incrementalAggrFuncCallbacks struct {
+	updateAggrFunc   func(iac *incrementalAggrContext, values []float64)
+	finalizeAggrFunc func(iac *incrementalAggrContext)
+}
+
+func getIncrementalAggrFuncCallbacks(name string) *incrementalAggrFuncCallbacks {
+	name = strings.ToLower(name)
+	return incrementalAggrFuncCallbacksMap[name]
+}
+
+type incrementalAggrContext struct {
+	ts     *timeseries
+	values []float64
+}
+
+func finalizeAggrCommon(iac *incrementalAggrContext) {
+	counts := iac.values
+	dstValues := iac.ts.Values
+	_ = dstValues[len(counts)-1]
+	for i, v := range counts {
+		if v == 0 {
+			dstValues[i] = nan
+		}
+	}
+}
+
+func updateAggrSum(iac *incrementalAggrContext, values []float64) {
+	dstValues := iac.ts.Values
+	dstCounts := iac.values
+	_ = dstValues[len(values)-1]
+	_ = dstCounts[len(values)-1]
+	for i, v := range values {
+		if math.IsNaN(v) {
+			continue
+		}
+		dstValues[i] += v
+		dstCounts[i] = 1
+	}
+}
+
+func updateAggrMin(iac *incrementalAggrContext, values []float64) {
+	dstValues := iac.ts.Values
+	dstCounts := iac.values
+	_ = dstValues[len(values)-1]
+	_ = dstCounts[len(values)-1]
+	for i, v := range values {
+		if math.IsNaN(v) {
+			continue
+		}
+		if dstCounts[i] == 0 {
+			dstValues[i] = v
+			dstCounts[i] = 1
+			continue
+		}
+		if v < dstValues[i] {
+			dstValues[i] = v
+		}
+	}
+}
+
+func updateAggrMax(iac *incrementalAggrContext, values []float64) {
+	dstValues := iac.ts.Values
+	dstCounts := iac.values
+	_ = dstValues[len(values)-1]
+	_ = dstCounts[len(values)-1]
+	for i, v := range values {
+		if math.IsNaN(v) {
+			continue
+		}
+		if dstCounts[i] == 0 {
+			dstValues[i] = v
+			dstCounts[i] = 1
+			continue
+		}
+		if v > dstValues[i] {
+			dstValues[i] = v
+		}
+	}
+}
+
+func updateAggrAvg(iac *incrementalAggrContext, values []float64) {
+	// Do not use `Rapid calculation methods` at https://en.wikipedia.org/wiki/Standard_deviation,
+	// since it is slower and has no obvious benefits in increased precision.
+	dstValues := iac.ts.Values
+	dstCounts := iac.values
+	_ = dstValues[len(values)-1]
+	_ = dstCounts[len(values)-1]
+	for i, v := range values {
+		if math.IsNaN(v) {
+			continue
+		}
+		if dstCounts[i] == 0 {
+			dstValues[i] = v
+			dstCounts[i] = 1
+			continue
+		}
+		dstValues[i] += v
+		dstCounts[i]++
+	}
+}
+
+func finalizeAggrAvg(iac *incrementalAggrContext) {
+	dstValues := iac.ts.Values
+	counts := iac.values
+	_ = dstValues[len(counts)-1]
+	for i, v := range counts {
+		if v == 0 {
+			dstValues[i] = nan
+			continue
+		}
+		dstValues[i] /= v
+	}
+}
+
+func updateAggrCount(iac *incrementalAggrContext, values []float64) {
+	dstValues := iac.ts.Values
+	_ = dstValues[len(values)-1]
+	for i, v := range values {
+		if math.IsNaN(v) {
+			continue
+		}
+		dstValues[i]++
+	}
+}
+
+func finalizeAggrCount(iac *incrementalAggrContext) {
+	// Nothing to do
+}
+
+func updateAggrSum2(iac *incrementalAggrContext, values []float64) {
+	dstValues := iac.ts.Values
+	dstCounts := iac.values
+	_ = dstValues[len(values)-1]
+	_ = dstCounts[len(values)-1]
+	for i, v := range values {
+		if math.IsNaN(v) {
+			continue
+		}
+		dstValues[i] += v * v
+		dstCounts[i] = 1
+	}
+}
+
+func updateAggrGeomean(iac *incrementalAggrContext, values []float64) {
+	dstValues := iac.ts.Values
+	dstCounts := iac.values
+	_ = dstValues[len(values)-1]
+	_ = dstCounts[len(values)-1]
+	for i, v := range values {
+		if math.IsNaN(v) {
+			continue
+		}
+		if dstCounts[i] == 0 {
+			dstValues[i] = v
+			dstCounts[i] = 1
+			continue
+		}
+		dstValues[i] *= v
+		dstCounts[i]++
+	}
+}
+
+func finalizeAggrGeomean(iac *incrementalAggrContext) {
+	dstValues := iac.ts.Values
+	counts := iac.values
+	_ = dstValues[len(counts)-1]
+	for i, v := range counts {
+		if v == 0 {
+			dstValues[i] = nan
+			continue
+		}
+		dstValues[i] = math.Pow(dstValues[i], 1/v)
+	}
+}

app/vmselect/promql/arch_arm64.go

@@ -0,0 +1,3 @@
+package promql
+
+const maxByteSliceLen = 1 << 40

app/vmselect/promql/binary_op.go

@@ -271,7 +271,7 @@ func adjustBinaryOpTags(be *binaryOpExpr, left, right []*timeseries) ([]*timeser
 			rvsLeft := make([]*timeseries, len(right))
 			tsLeft := left[0]
 			for i, tsRight := range right {
-				tsRight.MetricName.ResetMetricGroup()
+				resetMetricGroupIfRequired(be, tsRight)
 				rvsLeft[i] = tsLeft
 			}
 			return rvsLeft, right, right, nil
@@ -281,7 +281,7 @@ func adjustBinaryOpTags(be *binaryOpExpr, left, right []*timeseries) ([]*timeser
 			rvsRight := make([]*timeseries, len(left))
 			tsRight := right[0]
 			for i, tsLeft := range left {
-				tsLeft.MetricName.ResetMetricGroup()
+				resetMetricGroupIfRequired(be, tsLeft)
 				rvsRight[i] = tsRight
 			}
 			return left, rvsRight, left, nil
@@ -296,8 +296,13 @@ func adjustBinaryOpTags(be *binaryOpExpr, left, right []*timeseries) ([]*timeser
 		if len(tss) == 1 {
 			return nil
 		}
-		return fmt.Errorf(`duplicate timeseries on the %s side of %q: %s %s`, side, be.Op, stringMetricTags(&tss[0].MetricName), be.GroupModifier.AppendString(nil))
+		if mergeNonOverlappingTimeseries(tss) {
+			return nil
+		}
+		return fmt.Errorf(`duplicate timeseries on the %s side of %s %s: %s and %s`, side, be.Op, be.GroupModifier.AppendString(nil),
+			stringMetricTags(&tss[0].MetricName), stringMetricTags(&tss[1].MetricName))
 	}
+
 	var rvsLeft, rvsRight []*timeseries
 	mLeft, mRight := createTimeseriesMapByTagSet(be, left, right)
 	joinOp := strings.ToLower(be.JoinModifier.Op)
@@ -335,7 +340,7 @@ func adjustBinaryOpTags(be *binaryOpExpr, left, right []*timeseries) ([]*timeser
 			if err := ensureOneX("right", tssRight); err != nil {
 				return nil, nil, nil, err
 			}
-			tssLeft[0].MetricName.ResetMetricGroup()
+			resetMetricGroupIfRequired(be, tssLeft[0])
 			rvsLeft = append(rvsLeft, tssLeft[0])
 			rvsRight = append(rvsRight, tssRight[0])
 		default:
@@ -349,6 +354,19 @@ func adjustBinaryOpTags(be *binaryOpExpr, left, right []*timeseries) ([]*timeser
 	return rvsLeft, rvsRight, dst, nil
 }
 
+func resetMetricGroupIfRequired(be *binaryOpExpr, ts *timeseries) {
+	if isBinaryOpCmp(be.Op) && !be.Bool {
+		// Do not reset MetricGroup for non-boolean `compare` binary ops like Prometheus does.
+		return
+	}
+	switch be.Op {
+	case "default", "if", "ifnot":
+		// Do not reset MetricGroup for these ops.
+		return
+	}
+	ts.MetricName.ResetMetricGroup()
+}
+
 func binaryOpPlus(left, right float64) float64 {
 	return left + right
 }
@@ -497,3 +515,26 @@ func isScalar(arg []*timeseries) bool {
 	}
 	return len(mn.Tags) == 0
 }
+
+func mergeNonOverlappingTimeseries(tss []*timeseries) bool {
+	if len(tss) < 2 {
+		logger.Panicf("BUG: expecting at least two timeseries. Got %d", len(tss))
+	}
+
+	// Check whether time series in tss overlap.
+	var dst timeseries
+	dst.CopyFromShallowTimestamps(tss[0])
+	dstValues := dst.Values
+	for _, ts := range tss[1:] {
+		for i, value := range ts.Values {
+			if math.IsNaN(dstValues[i]) {
+				dstValues[i] = value
+			} else if !math.IsNaN(value) {
+				// Time series overlap.
+				return false
+			}
+		}
+	}
+	tss[0].CopyFromShallowTimestamps(&dst)
+	return true
+}

app/vmselect/promql/eval.go

@@ -16,10 +16,10 @@ import (
 )
 
 var (
-	maxPointsPerTimeseries = flag.Int("search.maxPointsPerTimeseries", 10e3, "The maximum points per a single timeseries returned from the search")
+	maxPointsPerTimeseries = flag.Int("search.maxPointsPerTimeseries", 30e3, "The maximum points per a single timeseries returned from the search")
 )
 
-// The minumum number of points per timeseries for enabling time rounding.
+// The minimum number of points per timeseries for enabling time rounding.
 // This improves cache hit ratio for frequently requested queries over
 // big time ranges.
 const minTimeseriesPointsForTimeRounding = 50
@@ -31,7 +31,7 @@ const minTimeseriesPointsForTimeRounding = 50
 func ValidateMaxPointsPerTimeseries(start, end, step int64) error {
 	points := (end-start)/step + 1
 	if uint64(points) > uint64(*maxPointsPerTimeseries) {
-		return fmt.Errorf(`too many points for the given step=%d, start=%d and end=%d: %d; cannot exceed %d points`,
+		return fmt.Errorf(`too many points for the given step=%d, start=%d and end=%d: %d; cannot exceed -search.maxPointsPerTimeseries=%d`,
 			step, start, end, uint64(points), *maxPointsPerTimeseries)
 	}
 	return nil
@@ -145,14 +145,14 @@ func evalExpr(ec *EvalConfig, e expr) ([]*timeseries, error) {
 		re := &rollupExpr{
 			Expr: me,
 		}
-		rv, err := evalRollupFunc(ec, "default_rollup", rollupDefault, re)
+		rv, err := evalRollupFunc(ec, "default_rollup", rollupDefault, re, nil)
 		if err != nil {
 			return nil, fmt.Errorf(`cannot evaluate %q: %s`, me.AppendString(nil), err)
 		}
 		return rv, nil
 	}
 	if re, ok := e.(*rollupExpr); ok {
-		rv, err := evalRollupFunc(ec, "default_rollup", rollupDefault, re)
+		rv, err := evalRollupFunc(ec, "default_rollup", rollupDefault, re, nil)
 		if err != nil {
 			return nil, fmt.Errorf(`cannot evaluate %q: %s`, re.AppendString(nil), err)
 		}
@@ -188,13 +188,30 @@ func evalExpr(ec *EvalConfig, e expr) ([]*timeseries, error) {
 		if err != nil {
 			return nil, err
 		}
-		rv, err := evalRollupFunc(ec, fe.Name, rf, re)
+		rv, err := evalRollupFunc(ec, fe.Name, rf, re, nil)
 		if err != nil {
 			return nil, fmt.Errorf(`cannot evaluate %q: %s`, fe.AppendString(nil), err)
 		}
 		return rv, nil
 	}
 	if ae, ok := e.(*aggrFuncExpr); ok {
+		if callbacks := getIncrementalAggrFuncCallbacks(ae.Name); callbacks != nil {
+			fe, nrf := tryGetArgRollupFuncWithMetricExpr(ae)
+			if fe != nil {
+				// There is an optimized path for calculating aggrFuncExpr over rollupFunc over metricExpr.
+				// The optimized path saves RAM for aggregates over big number of time series.
+				args, re, err := evalRollupFuncArgs(ec, fe)
+				if err != nil {
+					return nil, err
+				}
+				rf, err := nrf(args)
+				if err != nil {
+					return nil, err
+				}
+				iafc := newIncrementalAggrFuncContext(ae, callbacks)
+				return evalRollupFunc(ec, fe.Name, rf, re, iafc)
+			}
+		}
 		args, err := evalExprs(ec, ae.Args)
 		if err != nil {
 			return nil, err
@@ -249,6 +266,69 @@ func evalExpr(ec *EvalConfig, e expr) ([]*timeseries, error) {
 	return nil, fmt.Errorf("unexpected expression %q", e.AppendString(nil))
 }
 
+func tryGetArgRollupFuncWithMetricExpr(ae *aggrFuncExpr) (*funcExpr, newRollupFunc) {
+	if len(ae.Args) != 1 {
+		return nil, nil
+	}
+	e := ae.Args[0]
+	// Make sure e contains one of the following:
+	// - metricExpr
+	// - metricExpr[d]
+	// - rollupFunc(metricExpr)
+	// - rollupFunc(metricExpr[d])
+
+	if me, ok := e.(*metricExpr); ok {
+		// e = metricExpr
+		if me.IsEmpty() {
+			return nil, nil
+		}
+		fe := &funcExpr{
+			Name: "default_rollup",
+			Args: []expr{me},
+		}
+		nrf := getRollupFunc(fe.Name)
+		return fe, nrf
+	}
+	if re, ok := e.(*rollupExpr); ok {
+		if me, ok := re.Expr.(*metricExpr); !ok || me.IsEmpty() {
+			return nil, nil
+		}
+		// e = rollupExpr(metricExpr)
+		fe := &funcExpr{
+			Name: "default_rollup",
+			Args: []expr{re},
+		}
+		nrf := getRollupFunc(fe.Name)
+		return fe, nrf
+	}
+	fe, ok := e.(*funcExpr)
+	if !ok {
+		return nil, nil
+	}
+	nrf := getRollupFunc(fe.Name)
+	if nrf == nil {
+		return nil, nil
+	}
+	rollupArgIdx := getRollupArgIdx(fe.Name)
+	arg := fe.Args[rollupArgIdx]
+	if me, ok := arg.(*metricExpr); ok {
+		if me.IsEmpty() {
+			return nil, nil
+		}
+		return &funcExpr{
+			Name: fe.Name,
+			Args: []expr{me},
+		}, nrf
+	}
+	if re, ok := arg.(*rollupExpr); ok {
+		if me, ok := re.Expr.(*metricExpr); !ok || me.IsEmpty() {
+			return nil, nil
+		}
+		return fe, nrf
+	}
+	return nil, nil
+}
+
 func evalExprs(ec *EvalConfig, es []expr) ([][]*timeseries, error) {
 	var rvs [][]*timeseries
 	for _, e := range es {
@@ -308,7 +388,7 @@ func getRollupExprArg(arg expr) *rollupExpr {
 	return &reNew
 }
 
-func evalRollupFunc(ec *EvalConfig, name string, rf rollupFunc, re *rollupExpr) ([]*timeseries, error) {
+func evalRollupFunc(ec *EvalConfig, name string, rf rollupFunc, re *rollupExpr, iafc *incrementalAggrFuncContext) ([]*timeseries, error) {
 	ecNew := ec
 	var offset int64
 	if len(re.Offset) > 0 {
@@ -325,19 +405,11 @@ func evalRollupFunc(ec *EvalConfig, name string, rf rollupFunc, re *rollupExpr)
 	var rvs []*timeseries
 	var err error
 	if me, ok := re.Expr.(*metricExpr); ok {
-		if me.IsEmpty() {
-			rvs = evalNumber(ecNew, nan)
-		} else {
-			var window int64
-			if len(re.Window) > 0 {
-				window, err = DurationValue(re.Window, ec.Step)
-				if err != nil {
-					return nil, err
-				}
-			}
-			rvs, err = evalRollupFuncWithMetricExpr(ecNew, name, rf, me, window)
-		}
+		rvs, err = evalRollupFuncWithMetricExpr(ecNew, name, rf, me, iafc, re.Window)
 	} else {
+		if iafc != nil {
+			logger.Panicf("BUG: iafc must be nil for rollup %q over subquery %q", name, re.AppendString(nil))
+		}
 		rvs, err = evalRollupFuncWithSubquery(ecNew, name, rf, re)
 	}
 	if err != nil {
@@ -379,8 +451,7 @@ func evalRollupFuncWithSubquery(ec *EvalConfig, name string, rf rollupFunc, re *
 	}
 
 	ecSQ := newEvalConfig(ec)
-	ecSQ.Start -= window + maxSilenceInterval
-	ecSQ.End += step
+	ecSQ.Start -= window + maxSilenceInterval + step
 	ecSQ.Step = step
 	if err := ValidateMaxPointsPerTimeseries(ecSQ.Start, ecSQ.End, ecSQ.Step); err != nil {
 		return nil, err
@@ -407,6 +478,7 @@ func evalRollupFuncWithSubquery(ec *EvalConfig, name string, rf rollupFunc, re *
 			ts.Values = rc.Do(ts.Values[:0], values, timestamps)
 			ts.Timestamps = sharedTimestamps
 			ts.denyReuse = true
+
 			tssLock.Lock()
 			tss = append(tss, &ts)
 			tssLock.Unlock()
@@ -472,31 +544,27 @@ func removeNanValues(dstValues []float64, dstTimestamps []int64, values []float6
 	return dstValues, dstTimestamps
 }
 
-func getMaxPointsPerRollup() int {
-	maxPointsPerRollupOnce.Do(func() {
-		n := memory.Allowed() / 16 / 8
-		if n <= 16 {
-			n = 16
-		}
-		maxPointsPerRollup = n
-	})
-	return maxPointsPerRollup
-}
-
-var (
-	maxPointsPerRollup     int
-	maxPointsPerRollupOnce sync.Once
-)
-
 var (
 	rollupResultCacheFullHits    = metrics.NewCounter(`vm_rollup_result_cache_full_hits_total`)
 	rollupResultCachePartialHits = metrics.NewCounter(`vm_rollup_result_cache_partial_hits_total`)
 	rollupResultCacheMiss        = metrics.NewCounter(`vm_rollup_result_cache_miss_total`)
 )
 
-func evalRollupFuncWithMetricExpr(ec *EvalConfig, name string, rf rollupFunc, me *metricExpr, window int64) ([]*timeseries, error) {
+func evalRollupFuncWithMetricExpr(ec *EvalConfig, name string, rf rollupFunc, me *metricExpr, iafc *incrementalAggrFuncContext, windowStr string) ([]*timeseries, error) {
+	if me.IsEmpty() {
+		return evalNumber(ec, nan), nil
+	}
+	var window int64
+	if len(windowStr) > 0 {
+		var err error
+		window, err = DurationValue(windowStr, ec.Step)
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	// Search for partial results in cache.
-	tssCached, start := rollupResultCacheV.Get(name, ec, me, window)
+	tssCached, start := rollupResultCacheV.Get(name, ec, me, iafc, window)
 	if start > ec.End {
 		// The result is fully cached.
 		rollupResultCacheFullHits.Inc()
@@ -533,17 +601,83 @@ func evalRollupFuncWithMetricExpr(ec *EvalConfig, name string, rf rollupFunc, me
 	// Verify timeseries fit available memory after the rollup.
 	// Take into account points from tssCached.
 	pointsPerTimeseries := 1 + (ec.End-ec.Start)/ec.Step
-	if uint64(pointsPerTimeseries) > uint64(getMaxPointsPerRollup()/rssLen/len(rcs)) {
+	rollupPoints := mulNoOverflow(pointsPerTimeseries, int64(rssLen*len(rcs)))
+	rollupMemorySize := mulNoOverflow(rollupPoints, 16)
+	rml := getRollupMemoryLimiter()
+	if !rml.Get(uint64(rollupMemorySize)) {
 		rss.Cancel()
-		return nil, fmt.Errorf("cannot process more than %d data points for %d time series with %d points in each time series; "+
-			"possible solutions are: reducing the number of matching time series; switching to node with more RAM; increasing `step` query arg (%gs)",
-			getMaxPointsPerRollup(), rssLen*len(rcs), pointsPerTimeseries, float64(ec.Step)/1e3)
+		return nil, fmt.Errorf("not enough memory for processing %d data points across %d time series with %d points in each time series; "+
+			"possible solutions are: reducing the number of matching time series; switching to node with more RAM; "+
+			"increasing -memory.allowedPercent; increasing `step` query arg (%gs)",
+			rollupPoints, rssLen*len(rcs), pointsPerTimeseries, float64(ec.Step)/1e3)
 	}
+	defer rml.Put(uint64(rollupMemorySize))
 
 	// Evaluate rollup
-	tss := make([]*timeseries, 0, rssLen*len(rcs))
+	var tss []*timeseries
+	if iafc != nil {
+		tss, err = evalRollupWithIncrementalAggregate(iafc, rss, rcs, preFunc, sharedTimestamps)
+	} else {
+		tss, err = evalRollupNoIncrementalAggregate(rss, rcs, preFunc, sharedTimestamps)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	if !rollupFuncsKeepMetricGroup[name] {
+		tss = copyTimeseriesMetricNames(tss)
+		for _, ts := range tss {
+			ts.MetricName.ResetMetricGroup()
+		}
+	}
+	tss = mergeTimeseries(tssCached, tss, start, ec)
+	rollupResultCacheV.Put(name, ec, me, iafc, window, tss)
+
+	return tss, nil
+}
+
+var (
+	rollupMemoryLimiter     memoryLimiter
+	rollupMemoryLimiterOnce sync.Once
+)
+
+func getRollupMemoryLimiter() *memoryLimiter {
+	rollupMemoryLimiterOnce.Do(func() {
+		rollupMemoryLimiter.MaxSize = uint64(memory.Allowed()) / 4
+	})
+	return &rollupMemoryLimiter
+}
+
+func evalRollupWithIncrementalAggregate(iafc *incrementalAggrFuncContext, rss *netstorage.Results, rcs []*rollupConfig,
+	preFunc func(values []float64, timestamps []int64), sharedTimestamps []int64) ([]*timeseries, error) {
+	err := rss.RunParallel(func(rs *netstorage.Result) {
+		preFunc(rs.Values, rs.Timestamps)
+		ts := getTimeseries()
+		defer putTimeseries(ts)
+		for _, rc := range rcs {
+			ts.Reset()
+			ts.MetricName.CopyFrom(&rs.MetricName)
+			if len(rc.TagValue) > 0 {
+				ts.MetricName.AddTag("rollup", rc.TagValue)
+			}
+			ts.Values = rc.Do(ts.Values[:0], rs.Values, rs.Timestamps)
+			ts.Timestamps = sharedTimestamps
+			iafc.updateTimeseries(ts)
+			ts.Timestamps = nil
+		}
+	})
+	if err != nil {
+		return nil, err
+	}
+	tss := iafc.finalizeTimeseries()
+	return tss, nil
+}
+
+func evalRollupNoIncrementalAggregate(rss *netstorage.Results, rcs []*rollupConfig,
+	preFunc func(values []float64, timestamps []int64), sharedTimestamps []int64) ([]*timeseries, error) {
+	tss := make([]*timeseries, 0, rss.Len()*len(rcs))
 	var tssLock sync.Mutex
-	err = rss.RunParallel(func(rs *netstorage.Result) {
+	err := rss.RunParallel(func(rs *netstorage.Result) {
 		preFunc(rs.Values, rs.Timestamps)
 		for _, rc := range rcs {
 			var ts timeseries
@@ -563,15 +697,6 @@ func evalRollupFuncWithMetricExpr(ec *EvalConfig, name string, rf rollupFunc, me
 	if err != nil {
 		return nil, err
 	}
-	if !rollupFuncsKeepMetricGroup[name] {
-		tss = copyTimeseriesMetricNames(tss)
-		for _, ts := range tss {
-			ts.MetricName.ResetMetricGroup()
-		}
-	}
-	tss = mergeTimeseries(tssCached, tss, start, ec)
-	rollupResultCacheV.Put(name, ec, me, window, tss)
-
 	return tss, nil
 }
 
@@ -584,13 +709,14 @@ func getRollupConfigs(name string, rf rollupFunc, start, end, step, window int64
 	}
 	newRollupConfig := func(rf rollupFunc, tagValue string) *rollupConfig {
 		return &rollupConfig{
-			TagValue:   tagValue,
-			Func:       rf,
-			Start:      start,
-			End:        end,
-			Step:       step,
-			Window:     window,
-			Timestamps: sharedTimestamps,
+			TagValue:        tagValue,
+			Func:            rf,
+			Start:           start,
+			End:             end,
+			Step:            step,
+			Window:          window,
+			MayAdjustWindow: rollupFuncsMayAdjustWindow[name],
+			Timestamps:      sharedTimestamps,
 		}
 	}
 	appendRollupConfigs := func(dst []*rollupConfig) []*rollupConfig {
@@ -617,6 +743,11 @@ func getRollupConfigs(name string, rf rollupFunc, start, end, step, window int64
 			deltaValues(values)
 		}
 		rcs = appendRollupConfigs(rcs)
+	case "rollup_candlestick":
+		rcs = append(rcs, newRollupConfig(rollupFirst, "open"))
+		rcs = append(rcs, newRollupConfig(rollupLast, "close"))
+		rcs = append(rcs, newRollupConfig(rollupMin, "low"))
+		rcs = append(rcs, newRollupConfig(rollupMax, "high"))
 	default:
 		rcs = append(rcs, newRollupConfig(rf, ""))
 	}
@@ -653,3 +784,11 @@ func evalTime(ec *EvalConfig) []*timeseries {
 	}
 	return rv
 }
+
+func mulNoOverflow(a, b int64) int64 {
+	if math.MaxInt64/b < a {
+		// Overflow
+		return math.MaxInt64
+	}
+	return a * b
+}

app/vmselect/promql/exec.go

@@ -1,16 +1,21 @@
 package promql
 
 import (
+	"flag"
 	"fmt"
 	"math"
 	"sort"
 	"sync"
 	"sync/atomic"
+	"time"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/netstorage"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/metrics"
 )
 
+var logSlowQueryDuration = flag.Duration("search.logSlowQueryDuration", 5*time.Second, "Log queries with execution time exceeding this value. Zero disables slow query logging")
+
 // ExpandWithExprs expands WITH expressions inside q and returns the resulting
 // PromQL without WITH expressions.
 func ExpandWithExprs(q string) (string, error) {
@@ -22,8 +27,19 @@ func ExpandWithExprs(q string) (string, error) {
 	return string(buf), nil
 }
 
-// Exec executes q for the given ec until the deadline.
-func Exec(ec *EvalConfig, q string) ([]netstorage.Result, error) {
+// Exec executes q for the given ec.
+func Exec(ec *EvalConfig, q string, isFirstPointOnly bool) ([]netstorage.Result, error) {
+	if *logSlowQueryDuration > 0 {
+		startTime := time.Now()
+		defer func() {
+			d := time.Since(startTime)
+			if d >= *logSlowQueryDuration {
+				logger.Infof("slow query according to -search.logSlowQueryDuration=%s: duration=%s, start=%d, end=%d, step=%d, query=%q",
+					*logSlowQueryDuration, d, ec.Start/1000, ec.End/1000, ec.Step/1000, q)
+			}
+		}()
+	}
+
 	ec.validate()
 
 	e, err := parsePromQLWithCache(q)
@@ -50,6 +66,14 @@ func Exec(ec *EvalConfig, q string) ([]netstorage.Result, error) {
 	}
 	ec.End -= ec.Step
 
+	if isFirstPointOnly {
+		// Remove all the points except the first one from every time series.
+		for _, ts := range rv {
+			ts.Values = ts.Values[:1]
+			ts.Timestamps = ts.Timestamps[:1]
+		}
+	}
+
 	maySort := maySortResults(e, rv)
 	result, err := timeseriesToResult(rv, maySort)
 	if err != nil {

app/vmselect/promql/exec_test.go

@@ -62,7 +62,7 @@ func TestExecSuccess(t *testing.T) {
 			Deadline: netstorage.NewDeadline(time.Minute),
 		}
 		for i := 0; i < 5; i++ {
-			result, err := Exec(ec, q)
+			result, err := Exec(ec, q, false)
 			if err != nil {
 				t.Fatalf(`unexpected error when executing %q: %s`, q, err)
 			}
@@ -286,7 +286,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `time()[300s:100s] offset 100s`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{800, 1000, 1200, 1400, 1600, 1800},
+			Values:     []float64{900, 1100, 1300, 1500, 1700, 1900},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -297,7 +297,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `time()[1.5i:0.5i] offset 0.5i`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{800, 1000, 1200, 1400, 1600, 1800},
+			Values:     []float64{900, 1100, 1300, 1500, 1700, 1900},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -308,7 +308,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `time()[300s] offset 100s`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{700, 900, 1100, 1300, 1500, 1700},
+			Values:     []float64{900, 1100, 1300, 1500, 1700, 1900},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -319,7 +319,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `time()[300s]`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{800, 1000, 1200, 1400, 1600, 1800},
+			Values:     []float64{1000, 1200, 1400, 1600, 1800, 2000},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -574,6 +574,30 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run(`clamp_max(alias(time(),"foobar"), 1400)`, func(t *testing.T) {
+		t.Parallel()
+		q := `clamp_max(alias(time(), "foobar"), 1400)`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1000, 1200, 1400, 1400, 1400, 1400},
+			Timestamps: timestampsExpected,
+		}
+		r.MetricName.MetricGroup = []byte("foobar")
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
+	t.Run(`CLAmp_MAx(alias(time(),"foobar"), 1400)`, func(t *testing.T) {
+		t.Parallel()
+		q := `CLAmp_MAx(alias(time(), "foobar"), 1400)`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1000, 1200, 1400, 1400, 1400, 1400},
+			Timestamps: timestampsExpected,
+		}
+		r.MetricName.MetricGroup = []byte("foobar")
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
 	t.Run("clamp_min(time(), -time()+3000)", func(t *testing.T) {
 		t.Parallel()
 		q := `clamp_min(time(), -time()+2500)`
@@ -789,6 +813,18 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{}
 		f(q, resultExpected)
 	})
+	t.Run(`alias()`, func(t *testing.T) {
+		t.Parallel()
+		q := `alias(time(), "foobar")`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1000, 1200, 1400, 1600, 1800, 2000},
+			Timestamps: timestampsExpected,
+		}
+		r.MetricName.MetricGroup = []byte("foobar")
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
 	t.Run(`label_set(tag)`, func(t *testing.T) {
 		t.Parallel()
 		q := `label_set(time(), "tagname", "tagvalue")`
@@ -1266,6 +1302,34 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run(`label_transform(mismatch)`, func(t *testing.T) {
+		t.Parallel()
+		q := `label_transform(time(), "__name__", "foobar", "xx")`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1000, 1200, 1400, 1600, 1800, 2000},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
+	t.Run(`label_transform(match)`, func(t *testing.T) {
+		t.Parallel()
+		q := `label_transform(
+			label_set(time(), "foo", "a.bar.baz"),
+			"foo", "\\.", "-")`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1000, 1200, 1400, 1600, 1800, 2000},
+			Timestamps: timestampsExpected,
+		}
+		r.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("foo"),
+			Value: []byte("a-bar-baz"),
+		}}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
 	t.Run(`label_replace(mismatch)`, func(t *testing.T) {
 		t.Parallel()
 		q := `label_replace(time(), "__name__", "x${1}y", "foo", ".+")`
@@ -1410,6 +1474,62 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r1, r2}
 		f(q, resultExpected)
 	})
+	t.Run(`a cmp scalar (leave MetricGroup)`, func(t *testing.T) {
+		t.Parallel()
+		q := `sort_desc((
+			label_set(time(), "__name__", "foo", "a", "x"),
+			label_set(time()+200, "__name__", "bar", "a", "x"),
+		) > 1300)`
+		r1 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{nan, 1400, 1600, 1800, 2000, 2200},
+			Timestamps: timestampsExpected,
+		}
+		r1.MetricName.MetricGroup = []byte("bar")
+		r1.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("a"),
+			Value: []byte("x"),
+		}}
+		r2 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{nan, nan, 1400, 1600, 1800, 2000},
+			Timestamps: timestampsExpected,
+		}
+		r2.MetricName.MetricGroup = []byte("foo")
+		r2.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("a"),
+			Value: []byte("x"),
+		}}
+		resultExpected := []netstorage.Result{r1, r2}
+		f(q, resultExpected)
+	})
+	t.Run(`a cmp bool scalar (drop MetricGroup)`, func(t *testing.T) {
+		t.Parallel()
+		q := `sort_desc((
+			label_set(time(), "__name__", "foo", "a", "x"),
+			label_set(time()+200, "__name__", "bar", "a", "y"),
+		) >= bool 1200)`
+		r1 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1, 1, 1, 1, 1, 1},
+			Timestamps: timestampsExpected,
+		}
+		r1.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("a"),
+			Value: []byte("y"),
+		}}
+		r2 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{0, 1, 1, 1, 1, 1},
+			Timestamps: timestampsExpected,
+		}
+		r2.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("a"),
+			Value: []byte("x"),
+		}}
+		resultExpected := []netstorage.Result{r1, r2}
+		f(q, resultExpected)
+	})
 	t.Run(`1 > 2`, func(t *testing.T) {
 		t.Parallel()
 		q := `1 > 2`
@@ -1512,13 +1632,14 @@ func TestExecSuccess(t *testing.T) {
 	t.Run(`vector default scalar`, func(t *testing.T) {
 		t.Parallel()
 		q := `sort_desc(union(
-			label_set(time() > 1400, "foo", "bar"),
-			label_set(time() < 1700, "foo", "baz")) default 123)`
+			label_set(time() > 1400, "__name__", "x", "foo", "bar"),
+			label_set(time() < 1700, "__name__", "y", "foo", "baz")) default 123)`
 		r1 := netstorage.Result{
 			MetricName: metricNameExpected,
 			Values:     []float64{123, 123, 123, 1600, 1800, 2000},
 			Timestamps: timestampsExpected,
 		}
+		r1.MetricName.MetricGroup = []byte("x")
 		r1.MetricName.Tags = []storage.Tag{{
 			Key:   []byte("foo"),
 			Value: []byte("bar"),
@@ -1528,6 +1649,7 @@ func TestExecSuccess(t *testing.T) {
 			Values:     []float64{1000, 1200, 1400, 1600, 123, 123},
 			Timestamps: timestampsExpected,
 		}
+		r2.MetricName.MetricGroup = []byte("y")
 		r2.MetricName.Tags = []storage.Tag{{
 			Key:   []byte("foo"),
 			Value: []byte("baz"),
@@ -1699,6 +1821,24 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run(`vector * on(foo) group_left() duplicate_timeseries`, func(t *testing.T) {
+		t.Parallel()
+		q := `label_set(time()/10, "foo", "bar") + on(foo) group_left() (
+			label_set(time() < 1400, "foo", "bar", "op", "le"),
+			label_set(time() >= 1400, "foo", "bar", "op", "ge"),
+		)`
+		r1 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1100, 1320, 1540, 1760, 1980, 2200},
+			Timestamps: timestampsExpected,
+		}
+		r1.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("foo"),
+			Value: []byte("bar"),
+		}}
+		resultExpected := []netstorage.Result{r1}
+		f(q, resultExpected)
+	})
 	t.Run(`vector * on() group_left scalar`, func(t *testing.T) {
 		t.Parallel()
 		q := `sort_desc((label_set(time(), "foo", "bar") or label_set(10, "foo", "qwert")) * on() group_left 2)`
@@ -2068,6 +2208,17 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run(`avg(scalar) wiTHout (xx, yy)`, func(t *testing.T) {
+		t.Parallel()
+		q := `avg wiTHout (xx, yy) (123)`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{123, 123, 123, 123, 123, 123},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
 	t.Run(`sum(time)`, func(t *testing.T) {
 		t.Parallel()
 		q := `sum(time()/100)`
@@ -2079,6 +2230,51 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run(`geomean(time)`, func(t *testing.T) {
+		t.Parallel()
+		q := `geomean(time()/100)`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{10, 12, 14, 16, 18, 20},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
+	t.Run(`geomean_over_time(time)`, func(t *testing.T) {
+		t.Parallel()
+		q := `round(geomean_over_time(alias(time()/100, "foobar")[3i]), 0.1)`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{6.8, 8.8, 10.9, 12.9, 14.9, 16.9},
+			Timestamps: timestampsExpected,
+		}
+		r.MetricName.MetricGroup = []byte("foobar")
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
+	t.Run(`sum2(time)`, func(t *testing.T) {
+		t.Parallel()
+		q := `sum2(time()/100)`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{100, 144, 196, 256, 324, 400},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
+	t.Run(`sum2_over_time(time)`, func(t *testing.T) {
+		t.Parallel()
+		q := `sum2_over_time(alias(time()/100, "foobar")[3i])`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{155, 251, 371, 515, 683, 875},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
 	t.Run(`sum(multi-vector)`, func(t *testing.T) {
 		t.Parallel()
 		q := `sum(label_set(10, "foo", "bar") or label_set(time()/100, "baz", "sss"))`
@@ -2090,6 +2286,39 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run(`geomean(multi-vector)`, func(t *testing.T) {
+		t.Parallel()
+		q := `round(geomean(label_set(10, "foo", "bar") or label_set(time()/100, "baz", "sss")), 0.1)`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{10, 11, 11.8, 12.6, 13.4, 14.1},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
+	t.Run(`sum2(multi-vector)`, func(t *testing.T) {
+		t.Parallel()
+		q := `sum2(label_set(10, "foo", "bar") or label_set(time()/100, "baz", "sss"))`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{200, 244, 296, 356, 424, 500},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
+	t.Run(`sqrt(sum2(multi-vector))`, func(t *testing.T) {
+		t.Parallel()
+		q := `round(sqrt(sum2(label_set(10, "foo", "bar") or label_set(time()/100, "baz", "sss"))))`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{14, 16, 17, 19, 21, 22},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
 	t.Run(`avg(multi-vector)`, func(t *testing.T) {
 		t.Parallel()
 		q := `avg(label_set(10, "foo", "bar") or label_set(time()/100, "baz", "sss"))`
@@ -2279,6 +2508,21 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r1, r2}
 		f(q, resultExpected)
 	})
+	t.Run(`topk(1, nan_timeseries)`, func(t *testing.T) {
+		t.Parallel()
+		q := `topk(1, label_set(NaN, "foo", "bar") or label_set(time()/150, "baz", "sss")) default 0`
+		r1 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{6.666666666666667, 8, 9.333333333333334, 10.666666666666666, 12, 13.333333333333334},
+			Timestamps: timestampsExpected,
+		}
+		r1.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("baz"),
+			Value: []byte("sss"),
+		}}
+		resultExpected := []netstorage.Result{r1}
+		f(q, resultExpected)
+	})
 	t.Run(`topk(2)`, func(t *testing.T) {
 		t.Parallel()
 		q := `sort(topk(2, label_set(10, "foo", "bar") or label_set(time()/150, "baz", "sss")))`
@@ -2378,7 +2622,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `distinct_over_time((time() < 1700)[500s])`
 		r1 := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{3, 3, 3, 2, 1, nan},
+			Values:     []float64{3, 3, 3, 3, 2, 1},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r1}
@@ -2389,7 +2633,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `distinct_over_time((time() < 1700)[2.5i])`
 		r1 := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{3, 3, 3, 2, 1, nan},
+			Values:     []float64{3, 3, 3, 3, 2, 1},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r1}
@@ -2645,7 +2889,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `integrate(time()*1e-3)`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{200, 240.00000000000003, 280, 320, 360, 400},
+			Values:     []float64{160, 200, 240.00000000000003, 280, 320, 360},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -2667,7 +2911,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `rate(2000-time())`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{4.5, 3.5, 2.5, 1.5, 0.5, -0.5},
+			Values:     []float64{5.5, 4.5, 3.5, 2.5, 1.5, 0.5},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -2678,7 +2922,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `rate((2000-time())[100s])`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{4.5, 3.5, 2.5, 1.5, 0.5, -0.5},
+			Values:     []float64{5.5, 4.5, 3.5, 2.5, 1.5, 0.5},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -2689,7 +2933,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `rate((2000-time())[100s:])`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{4.5, 3.5, 2.5, 1.5, 0.5, -0.5},
+			Values:     []float64{5.5, 4.5, 3.5, 2.5, 1.5, 0.5},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -2700,7 +2944,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `rate((2000-time())[100s:100s])`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{4, 6.5, 4.5, 2.5, 0.5, -1.5},
+			Values:     []float64{5.5, 4.5, 6.5, 4.5, 2.5, 0.5},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -2711,7 +2955,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `rate((2000-time())[100s:100s] offset 100s)`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{4.5, 3.5, 5.5, 3.5, 1.5, -0.5},
+			Values:     []float64{6, 5, 7.5, 5.5, 3.5, 1.5},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -2722,7 +2966,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `rate((2000-time())[100s:100s] offset 100s)[:] offset 100s`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{6, 5, 7.5, 5.5, 3.5, 1.5},
+			Values:     []float64{7, 6, 5, 7.5, 5.5, 3.5},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -2744,7 +2988,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `increase(2000-time())`
 		r := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{900, 700, 500, 300, 100, -100},
+			Values:     []float64{1100, 900, 700, 500, 300, 100},
 			Timestamps: timestampsExpected,
 		}
 		resultExpected := []netstorage.Result{r}
@@ -3009,6 +3253,48 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run(`rollup_candlestick()`, func(t *testing.T) {
+		t.Parallel()
+		q := `sort(rollup_candlestick(round(rand(0),0.01)[:10s]))`
+		r1 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{0.02, 0.02, 0.03, 0, 0.03, 0.02},
+			Timestamps: timestampsExpected,
+		}
+		r1.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("rollup"),
+			Value: []byte("low"),
+		}}
+		r2 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{0.32, 0.82, 0.13, 0.28, 0.86, 0.57},
+			Timestamps: timestampsExpected,
+		}
+		r2.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("rollup"),
+			Value: []byte("close"),
+		}}
+		r3 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{0.9, 0.32, 0.82, 0.13, 0.28, 0.86},
+			Timestamps: timestampsExpected,
+		}
+		r3.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("rollup"),
+			Value: []byte("open"),
+		}}
+		r4 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{0.85, 0.94, 0.97, 0.93, 0.98, 0.92},
+			Timestamps: timestampsExpected,
+		}
+		r4.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("rollup"),
+			Value: []byte("high"),
+		}}
+		resultExpected := []netstorage.Result{r1, r2, r3, r4}
+		f(q, resultExpected)
+	})
 	t.Run(`rollup_increase()`, func(t *testing.T) {
 		t.Parallel()
 		q := `sort(rollup_increase(time()))`
@@ -3047,7 +3333,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `sort(rollup(time()[:50s]))`
 		r1 := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{1050, 1250, 1450, 1650, 1850, 2050},
+			Values:     []float64{850, 1050, 1250, 1450, 1650, 1850},
 			Timestamps: timestampsExpected,
 		}
 		r1.MetricName.Tags = []storage.Tag{{
@@ -3056,21 +3342,21 @@ func TestExecSuccess(t *testing.T) {
 		}}
 		r2 := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{1200, 1400, 1600, 1800, 2000, 2200},
+			Values:     []float64{925, 1125, 1325, 1525, 1725, 1925},
 			Timestamps: timestampsExpected,
 		}
 		r2.MetricName.Tags = []storage.Tag{{
 			Key:   []byte("rollup"),
-			Value: []byte("max"),
+			Value: []byte("avg"),
 		}}
 		r3 := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{1125, 1325, 1525, 1725, 1925, 2125},
+			Values:     []float64{1000, 1200, 1400, 1600, 1800, 2000},
 			Timestamps: timestampsExpected,
 		}
 		r3.MetricName.Tags = []storage.Tag{{
 			Key:   []byte("rollup"),
-			Value: []byte("avg"),
+			Value: []byte("max"),
 		}}
 		resultExpected := []netstorage.Result{r1, r2, r3}
 		f(q, resultExpected)
@@ -3429,7 +3715,14 @@ func TestExecError(t *testing.T) {
 			Deadline: netstorage.NewDeadline(time.Minute),
 		}
 		for i := 0; i < 4; i++ {
-			rv, err := Exec(ec, q)
+			rv, err := Exec(ec, q, false)
+			if err == nil {
+				t.Fatalf(`expecting non-nil error on %q`, q)
+			}
+			if rv != nil {
+				t.Fatalf(`expecting nil rv`)
+			}
+			rv, err = Exec(ec, q, true)
 			if err == nil {
 				t.Fatalf(`expecting non-nil error on %q`, q)
 			}
@@ -3461,6 +3754,7 @@ func TestExecError(t *testing.T) {
 	f(`hour(1,2)`)
 	f(`label_join()`)
 	f(`label_replace(1)`)
+	f(`label_transform(1)`)
 	f(`label_set()`)
 	f(`label_set(1, "foo")`)
 	f(`label_del()`)
@@ -3506,6 +3800,9 @@ func TestExecError(t *testing.T) {
 	f(`keep_last_value()`)
 	f(`distinct_over_time()`)
 	f(`distinct()`)
+	f(`alias()`)
+	f(`alias(1)`)
+	f(`alias(1, "foo", "bar")`)
 
 	// Invalid argument type
 	f(`median_over_time({}, 2)`)
@@ -3535,6 +3832,11 @@ func TestExecError(t *testing.T) {
 	f(`label_replace(1, "foo", "bar", 4, 5)`)
 	f(`label_replace(1, "foo", "bar", "baz", 5)`)
 	f(`label_replace(1, "foo", "bar", "baz", "invalid(regexp")`)
+	f(`label_transform(1, 2, 3, 4)`)
+	f(`label_transform(1, "foo", 3, 4)`)
+	f(`label_transform(1, "foo", "bar", 4)`)
+	f(`label_transform(1, "foo", "invalid(regexp", "baz`)
+	f(`alias(1, 2)`)
 
 	// Duplicate timeseries
 	f(`(label_set(1, "foo", "bar") or label_set(2, "foo", "baz"))
@@ -3545,12 +3847,31 @@ func TestExecError(t *testing.T) {
 	f(`1 + group_left() (label_set(1, "foo", bar"), label_set(2, "foo", "baz"))`)
 	f(`1 + on() group_left() (label_set(1, "foo", bar"), label_set(2, "foo", "baz"))`)
 	f(`1 + on(a) group_left(b) (label_set(1, "foo", bar"), label_set(2, "foo", "baz"))`)
+	f(`label_set(1, "foo", "bar") + on(foo) group_left() (label_set(1, "foo", "bar", "a", "b"), label_set(1, "foo", "bar", "a", "c"))`)
 	f(`(label_set(1, "foo", bar"), label_set(2, "foo", "baz")) + group_right 1`)
 	f(`(label_set(1, "foo", bar"), label_set(2, "foo", "baz")) + on() group_right 1`)
 	f(`(label_set(1, "foo", bar"), label_set(2, "foo", "baz")) + on(a) group_right(b,c) 1`)
 	f(`(label_set(1, "foo", bar"), label_set(2, "foo", "baz")) + on() 1`)
+	f(`(label_set(1, "foo", "bar", "a", "b"), label_set(1, "foo", "bar", "a", "c")) + on(foo) group_right() label_set(1, "foo", "bar")`)
 	f(`1 + on() (label_set(1, "foo", bar"), label_set(2, "foo", "baz"))`)
 
+	// duplicate metrics after binary op
+	f(`(
+		label_set(time(), "__name__", "foo", "a", "x"),
+		label_set(time()+200, "__name__", "bar", "a", "x"),
+	) > bool 1300`)
+	f(`(
+		label_set(time(), "__name__", "foo", "a", "x"),
+		label_set(time()+200, "__name__", "bar", "a", "x"),
+	) + 10`)
+
+	// Invalid aggregates
+	f(`sum(1, 2)`)
+	f(`sum(1) foo (bar)`)
+	f(`sum foo () (bar)`)
+	f(`sum(foo) by (1)`)
+	f(`count(foo) without ("bar")`)
+
 	// With expressions
 	f(`ttf()`)
 	f(`ttf(1, 2)`)

app/vmselect/promql/lexer.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 )
 
 type lexer struct {
@@ -85,10 +87,7 @@ again:
 		goto tokenFoundLabel
 	}
 	if isIdentPrefix(s) {
-		token, err = scanIdent(s)
-		if err != nil {
-			return "", err
-		}
+		token = scanIdent(s)
 		goto tokenFoundLabel
 	}
 	if isStringPrefix(s) {
@@ -210,15 +209,103 @@ func scanPositiveNumber(s string) (string, error) {
 	return s[:j], nil
 }
 
-func scanIdent(s string) (string, error) {
-	if len(s) == 0 {
-		return "", fmt.Errorf("ident cannot be empty")
-	}
+func scanIdent(s string) string {
 	i := 0
-	for i < len(s) && isIdentChar(s[i]) {
-		i++
+	for i < len(s) {
+		if isIdentChar(s[i]) {
+			i++
+			continue
+		}
+		if s[i] != '\\' {
+			break
+		}
+
+		// Do not verify the next char, since it is escaped.
+		i += 2
+		if i > len(s) {
+			i--
+			break
+		}
 	}
-	return s[:i], nil
+	if i == 0 {
+		logger.Panicf("BUG: scanIdent couldn't find a single ident char; make sure isIdentPrefix called before scanIdent")
+	}
+	return s[:i]
+}
+
+func unescapeIdent(s string) string {
+	n := strings.IndexByte(s, '\\')
+	if n < 0 {
+		return s
+	}
+	dst := make([]byte, 0, len(s))
+	for {
+		dst = append(dst, s[:n]...)
+		s = s[n+1:]
+		if len(s) == 0 {
+			return string(dst)
+		}
+		if s[0] == 'x' && len(s) >= 3 {
+			h1 := fromHex(s[1])
+			h2 := fromHex(s[2])
+			if h1 >= 0 && h2 >= 0 {
+				dst = append(dst, byte((h1<<4)|h2))
+				s = s[3:]
+			} else {
+				dst = append(dst, s[0])
+				s = s[1:]
+			}
+		} else {
+			dst = append(dst, s[0])
+			s = s[1:]
+		}
+		n = strings.IndexByte(s, '\\')
+		if n < 0 {
+			dst = append(dst, s...)
+			return string(dst)
+		}
+	}
+}
+
+func fromHex(ch byte) int {
+	if ch >= '0' && ch <= '9' {
+		return int(ch - '0')
+	}
+	if ch >= 'a' && ch <= 'f' {
+		return int((ch - 'a') + 10)
+	}
+	if ch >= 'A' && ch <= 'F' {
+		return int((ch - 'A') + 10)
+	}
+	return -1
+}
+
+func toHex(n byte) byte {
+	if n < 10 {
+		return '0' + n
+	}
+	return 'a' + (n - 10)
+}
+
+func appendEscapedIdent(dst, s []byte) []byte {
+	for i := 0; i < len(s); i++ {
+		ch := s[i]
+		if isIdentChar(ch) {
+			if i == 0 && !isFirstIdentChar(ch) {
+				// hex-encode the first char
+				dst = append(dst, '\\', 'x', toHex(ch>>4), toHex(ch&0xf))
+			} else {
+				dst = append(dst, ch)
+			}
+		} else if ch >= 0x20 && ch < 0x7f {
+			// Leave ASCII printable chars as is
+			dst = append(dst, '\\', ch)
+		} else {
+			// hex-encode non-printable chars
+			dst = append(dst, '\\', 'x', toHex(ch>>4), toHex(ch&0xf))
+		}
+	}
+	return dst
 }
 
 func (lex *lexer) Prev() {
@@ -353,6 +440,10 @@ func isIdentPrefix(s string) bool {
 	if len(s) == 0 {
 		return false
 	}
+	if s[0] == '\\' {
+		// Assume this is an escape char for the next char.
+		return true
+	}
 	return isFirstIdentChar(s[0])
 }
 
@@ -367,7 +458,7 @@ func isIdentChar(ch byte) bool {
 	if isFirstIdentChar(ch) {
 		return true
 	}
-	return isDecimalChar(ch) || ch == ':' || ch == '.'
+	return isDecimalChar(ch) || ch == '.'
 }
 
 func isSpaceChar(ch byte) bool {

app/vmselect/promql/lexer_test.go

@@ -5,6 +5,57 @@ import (
 	"testing"
 )
 
+func TestUnescapeIdent(t *testing.T) {
+	f := func(s, resultExpected string) {
+		t.Helper()
+		result := unescapeIdent(s)
+		if result != resultExpected {
+			t.Fatalf("unexpected result for unescapeIdent(%q); got %q; want %q", s, result, resultExpected)
+		}
+	}
+	f("", "")
+	f("a", "a")
+	f("\\", "")
+	f(`\\`, `\`)
+	f(`\foo\-bar`, `foo-bar`)
+	f(`a\\\\b\"c\d`, `a\\b"cd`)
+	f(`foo.bar:baz_123`, `foo.bar:baz_123`)
+	f(`foo\ bar`, `foo bar`)
+	f(`\x21`, `!`)
+	f(`\xeDfoo\x2Fbar\-\xqw\x`, "\xedfoo\x2fbar-xqwx")
+}
+
+func TestAppendEscapedIdent(t *testing.T) {
+	f := func(s, resultExpected string) {
+		t.Helper()
+		result := appendEscapedIdent(nil, []byte(s))
+		if string(result) != resultExpected {
+			t.Fatalf("unexpected result for appendEscapedIdent(%q); got %q; want %q", s, result, resultExpected)
+		}
+	}
+	f(`a`, `a`)
+	f(`a.b:c_23`, `a.b:c_23`)
+	f(`a b-cd+dd\`, `a\ b\-cd\+dd\\`)
+	f("a\x1E\x20\xee", `a\x1e\ \xee`)
+	f("\x2e\x2e", `\x2e.`)
+}
+
+func TestScanIdent(t *testing.T) {
+	f := func(s, resultExpected string) {
+		t.Helper()
+		result := scanIdent(s)
+		if result != resultExpected {
+			t.Fatalf("unexpected result for scanIdent(%q): got %q; want %q", s, result, resultExpected)
+		}
+	}
+	f("a", "a")
+	f("foo.bar:baz_123", "foo.bar:baz_123")
+	f("a+b", "a")
+	f("foo()", "foo")
+	f(`a\-b+c`, `a\-b`)
+	f(`a\ b\\\ c\`, `a\ b\\\ c\`)
+}
+
 func TestLexerNextPrev(t *testing.T) {
 	var lex lexer
 	lex.Init("foo bar baz")

app/vmselect/promql/memory_limiter.go

@@ -0,0 +1,33 @@
+package promql
+
+import (
+	"sync"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+)
+
+type memoryLimiter struct {
+	MaxSize uint64
+
+	mu    sync.Mutex
+	usage uint64
+}
+
+func (ml *memoryLimiter) Get(n uint64) bool {
+	ml.mu.Lock()
+	ok := n <= ml.MaxSize && ml.MaxSize-n >= ml.usage
+	if ok {
+		ml.usage += n
+	}
+	ml.mu.Unlock()
+	return ok
+}
+
+func (ml *memoryLimiter) Put(n uint64) {
+	ml.mu.Lock()
+	if n > ml.usage {
+		logger.Panicf("BUG: n=%d cannot exceed %d", n, ml.usage)
+	}
+	ml.usage -= n
+	ml.mu.Unlock()
+}

app/vmselect/promql/memory_limiter_test.go

@@ -0,0 +1,56 @@
+package promql
+
+import (
+	"testing"
+)
+
+func TestMemoryLimiter(t *testing.T) {
+	var ml memoryLimiter
+	ml.MaxSize = 100
+
+	// Allocate memory
+	if !ml.Get(10) {
+		t.Fatalf("cannot get 10 out of %d bytes", ml.MaxSize)
+	}
+	if ml.usage != 10 {
+		t.Fatalf("unexpected usage; got %d; want %d", ml.usage, 10)
+	}
+	if !ml.Get(20) {
+		t.Fatalf("cannot get 20 out of 90 bytes")
+	}
+	if ml.usage != 30 {
+		t.Fatalf("unexpected usage; got %d; want %d", ml.usage, 30)
+	}
+	if ml.Get(1000) {
+		t.Fatalf("unexpected get for 1000 bytes")
+	}
+	if ml.usage != 30 {
+		t.Fatalf("unexpected usage; got %d; want %d", ml.usage, 30)
+	}
+	if ml.Get(71) {
+		t.Fatalf("unexpected get for 71 bytes")
+	}
+	if ml.usage != 30 {
+		t.Fatalf("unexpected usage; got %d; want %d", ml.usage, 30)
+	}
+	if !ml.Get(70) {
+		t.Fatalf("cannot get 70 bytes")
+	}
+	if ml.usage != 100 {
+		t.Fatalf("unexpected usage; got %d; want %d", ml.usage, 100)
+	}
+
+	// Return memory back
+	ml.Put(10)
+	ml.Put(70)
+	if ml.usage != 20 {
+		t.Fatalf("unexpected usage; got %d; want %d", ml.usage, 20)
+	}
+	if !ml.Get(30) {
+		t.Fatalf("cannot get 30 bytes")
+	}
+	ml.Put(50)
+	if ml.usage != 0 {
+		t.Fatalf("unexpected usage; got %d; want %d", ml.usage, 0)
+	}
+}

app/vmselect/promql/parser.go

@@ -6,7 +6,6 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/storage"
 )
@@ -19,12 +18,13 @@ func getDefaultWithArgExprs() []*withArgExpr {
 
 			// ttf - time to fuckup
 			`ttf(freev) = smooth_exponential(
-				clamp_max(clamp_min(freev, 0) / clamp_min(deriv(-freev), 0), 365*24*3600),
+				clamp_max(clamp_max(-freev, 0) / clamp_max(deriv_fast(freev), 0), 365*24*3600),
 				clamp_max(step()/300, 1)
 			)`,
 
 			`median_over_time(m) = quantile_over_time(0.5, m)`,
 			`range_median(q) = range_quantile(0.5, q)`,
+			`alias(q, name) = label_set(q, "__name__", name)`,
 		})
 	})
 	return defaultWithArgExprs
@@ -744,7 +744,7 @@ func expandWithExpr(was []*withArgExpr, e expr) (expr, error) {
 		if !t.HasNonEmptyMetricGroup() {
 			return t, nil
 		}
-		k := bytesutil.ToUnsafeString(t.TagFilters[0].Value)
+		k := string(appendEscapedIdent(nil, t.TagFilters[0].Value))
 		wa := getWithArgExpr(was, k)
 		if wa == nil {
 			return t, nil
@@ -811,7 +811,9 @@ func expandModifierArgs(was []*withArgExpr, args []string) ([]string, error) {
 			continue
 		}
 		if len(wa.Args) > 0 {
-			return nil, fmt.Errorf("cannot use func %q instead of %q in %s", wa.Name, arg, args)
+			// Template funcs cannot be used inside modifier list. Leave the arg as is.
+			dstArgs = append(dstArgs, arg)
+			continue
 		}
 		me, ok := wa.Expr.(*metricExpr)
 		if ok {
@@ -851,6 +853,10 @@ func expandModifierArgs(was []*withArgExpr, args []string) ([]string, error) {
 
 func expandWithExprExt(was []*withArgExpr, wa *withArgExpr, args []expr) (expr, error) {
 	if len(wa.Args) != len(args) {
+		if args == nil {
+			// Just return metricExpr with the wa.Name name.
+			return newMetricExpr(wa.Name), nil
+		}
 		return nil, fmt.Errorf("invalid number of args for %q; got %d; want %d", wa.Name, len(args), len(wa.Args))
 	}
 	wasNew := make([]*withArgExpr, 0, len(was)+len(args))
@@ -869,6 +875,14 @@ func expandWithExprExt(was []*withArgExpr, wa *withArgExpr, args []expr) (expr,
 	return expandWithExpr(wasNew, wa.Expr)
 }
 
+func newMetricExpr(name string) *metricExpr {
+	return &metricExpr{
+		TagFilters: []storage.TagFilter{{
+			Value: []byte(name),
+		}},
+	}
+}
+
 func extractStringValue(token string) (string, error) {
 	if !isStringPrefix(token) {
 		return "", fmt.Errorf(`stringExpr must contain only string literals; got %q`, token)
@@ -1074,9 +1088,6 @@ func (p *parser) parseTagFilterExpr() (*tagFilterExpr, error) {
 	}
 	var tfe tagFilterExpr
 	tfe.Key = p.lex.Token
-	if tfe.Key == "__name__" {
-		tfe.Key = ""
-	}
 	if err := p.lex.Next(); err != nil {
 		return nil, err
 	}
@@ -1125,8 +1136,16 @@ func (tfe *tagFilterExpr) toTagFilter() (*storage.TagFilter, error) {
 	}
 
 	var tf storage.TagFilter
-	tf.Key = []byte(tfe.Key)
-	tf.Value = []byte(tfe.Value.S)
+	tf.Key = []byte(unescapeIdent(tfe.Key))
+	if len(tfe.Key) == 0 {
+		tf.Value = []byte(unescapeIdent(tfe.Value.S))
+	} else {
+		tf.Value = []byte(tfe.Value.S)
+	}
+	if string(tf.Key) == "__name__" {
+		// This is required for storage.Search
+		tf.Key = nil
+	}
 	tf.IsRegexp = tfe.IsRegexp
 	tf.IsNegative = tfe.IsNegative
 	if !tf.IsRegexp {
@@ -1507,7 +1526,7 @@ func (wa *withArgExpr) AppendString(dst []byte) []byte {
 }
 
 type rollupExpr struct {
-	// The expression for the rollup. Usually it is metricExpr, but may be arbitary expr
+	// The expression for the rollup. Usually it is metricExpr, but may be arbitrary expr
 	// if subquery is used. https://prometheus.io/blog/2019/01/28/subquery-support/
 	Expr expr
 
@@ -1585,7 +1604,7 @@ func (me *metricExpr) AppendString(dst []byte) []byte {
 	if len(tfs) > 0 {
 		tf := &tfs[0]
 		if len(tf.Key) == 0 && !tf.IsNegative && !tf.IsRegexp {
-			dst = append(dst, tf.Value...)
+			dst = appendEscapedIdent(dst, tf.Value)
 			tfs = tfs[1:]
 		}
 	}
@@ -1627,7 +1646,7 @@ func appendStringTagFilter(dst []byte, tf *storage.TagFilter) []byte {
 	if len(tf.Key) == 0 {
 		dst = append(dst, "__name__"...)
 	} else {
-		dst = append(dst, tf.Key...)
+		dst = appendEscapedIdent(dst, tf.Key)
 	}
 	var op string
 	if tf.IsNegative {

app/vmselect/promql/parser_test.go

@@ -118,6 +118,17 @@ func TestParsePromQLSuccess(t *testing.T) {
 	same("with")
 	same("WITH")
 	same("With")
+	same("alias")
+	same(`alias{foo="bar"}`)
+	same(`aLIas{alias="aa"}`)
+	another(`al\ias`, `alias`)
+	// identifiers with with escape chars
+	same(`foo\ bar`)
+	same(`foo\-bar\{{baz\+bar="aa"}`)
+	another(`\x2E\x2ef\oo{b\xEF\ar="aa"}`, `\x2e.foo{b\xefar="aa"}`)
+	// Duplicate filters
+	same(`foo{__name__="bar"}`)
+	same(`foo{a="b", a="c", __name__="aaa", b="d"}`)
 	// Metric filters ending with comma
 	another(`m{foo="bar",}`, `m{foo="bar"}`)
 	// String concat in tag value
@@ -251,6 +262,8 @@ func TestParsePromQLSuccess(t *testing.T) {
 	same(`rate(rate(m[5m]))`)
 	same(`rate(rate(m[5m])[1h:])`)
 	same(`rate(rate(m[5m])[1h:3s])`)
+	// funcName with escape chars
+	same(`foo\(ba\-r()`)
 
 	// aggrFuncExpr
 	same(`sum(http_server_request) by ()`)
@@ -295,10 +308,14 @@ func TestParsePromQLSuccess(t *testing.T) {
 	another(`with (ct={job="test", i="bar"}) ct + {ct, x="d"} + foo{ct, ct} + ctx(1)`,
 		`(({job="test", i="bar"} + {job="test", i="bar", x="d"}) + foo{job="test", i="bar"}) + ctx(1)`)
 	another(`with (foo = bar) {__name__=~"foo"}`, `{__name__=~"foo"}`)
-	another(`with (foo = bar) {__name__="foo"}`, `bar`)
+	another(`with (foo = bar) foo{__name__="foo"}`, `bar`)
 	another(`with (foo = bar) {__name__="foo", x="y"}`, `bar{x="y"}`)
 	another(`with (foo(bar) = {__name__!="bar"}) foo(x)`, `{__name__!="bar"}`)
-	another(`with (foo(bar) = {__name__="bar"}) foo(x)`, `x`)
+	another(`with (foo(bar) = bar{__name__="bar"}) foo(x)`, `x`)
+	another(`with (foo\-bar(baz) = baz + baz) foo\-bar((x,y))`, `(x, y) + (x, y)`)
+	another(`with (foo\-bar(baz) = baz + baz) foo\-bar(x*y)`, `(x * y) + (x * y)`)
+	another(`with (foo\-bar(baz) = baz + baz) foo\-bar(x\*y)`, `x\*y + x\*y`)
+	another(`with (foo\-bar(b\ az) = b\ az + b\ az) foo\-bar(x\*y)`, `x\*y + x\*y`)
 	// override ttf to something new.
 	another(`with (ttf = a) ttf + b`, `a + b`)
 	// override ttf to ru
@@ -332,8 +349,11 @@ func TestParsePromQLSuccess(t *testing.T) {
 	another(`with (x="a", y=x) y+"bc"`, `"abc"`)
 	another(`with (x="a", y="b"+x) "we"+y+"z"+f()`, `"webaz" + f()`)
 	another(`with (f(x) = m{foo=x+"y", bar="y"+x, baz=x} + x) f("qwe")`, `m{foo="qwey", bar="yqwe", baz="qwe"} + "qwe"`)
+	another(`with (f(a)=a) f`, `f`)
+	another(`with (f\q(a)=a) f\q`, `fq`)
 
 	// Verify withExpr for aggr func modifiers
+	another(`with (f(x) = x, y = sum(m) by (f)) y`, `sum(m) by (f)`)
 	another(`with (f(x) = sum(m) by (x)) f(foo)`, `sum(m) by (foo)`)
 	another(`with (f(x) = sum(m) by (x)) f((foo, bar, foo))`, `sum(m) by (foo, bar)`)
 	another(`with (f(x) = sum(m) without (x,y)) f((a, b))`, `sum(m) without (a, b, y)`)
@@ -658,7 +678,7 @@ func TestParsePromQLError(t *testing.T) {
 	f(`with (x=m) f(b, a{x})`)
 	f(`with (x=m) sum(a{x})`)
 	f(`with (x=m) (a{x})`)
-	f(`with (f(a)=a) f`)
+	f(`with (f(a)=a) f(1, 2)`)
 	f(`with (f(x)=x{foo="bar"}) f(1)`)
 	f(`with (f(x)=x{foo="bar"}) f(m + n)`)
 	f(`with (f = with`)
@@ -668,8 +688,7 @@ func TestParsePromQLError(t *testing.T) {
 	f(`with (f(,)=x) x`)
 	f(`with (x(a) = {b="c"}) foo{x}`)
 	f(`with (f(x) = m{foo=xx}) f("qwe")`)
-	f(`a + with(f(x)=x) f`)
-	f(`with (f(x) = x, y = sum(m) by (f)) y`)
+	f(`a + with(f(x)=x) f(1,2)`)
 	f(`with (f(x) = sum(m) by (x)) f({foo="bar"})`)
 	f(`with (f(x) = sum(m) by (x)) f((xx(), {foo="bar"}))`)
 	f(`with (f(x) = m + on (x) n) f(xx())`)

app/vmselect/promql/regexp_cache.go

@@ -1,7 +1,6 @@
 package promql
 
 import (
-	"fmt"
 	"regexp"
 	"sync"
 	"sync/atomic"
@@ -10,12 +9,16 @@ import (
 )
 
 func compileRegexpAnchored(re string) (*regexp.Regexp, error) {
+	reAnchored := "^(?:" + re + ")$"
+	return compileRegexp(reAnchored)
+}
+
+func compileRegexp(re string) (*regexp.Regexp, error) {
 	rcv := regexpCacheV.Get(re)
 	if rcv != nil {
 		return rcv.r, rcv.err
 	}
-	regexAnchored := fmt.Sprintf("^(?:%s)$", re)
-	r, err := regexp.Compile(regexAnchored)
+	r, err := regexp.Compile(re)
 	rcv = &regexpCacheValue{
 		r:   r,
 		err: err,
@@ -77,7 +80,7 @@ func (rc *regexpCache) Get(regexp string) *regexpCacheValue {
 	rcv := rc.m[regexp]
 	rc.mu.RUnlock()
 
-	if rc == nil {
+	if rcv == nil {
 		atomic.AddUint64(&rc.misses, 1)
 	}
 	return rcv

app/vmselect/promql/rollup.go

@@ -19,13 +19,14 @@ var rollupFuncs = map[string]newRollupFunc{
 	// See funcs accepting range-vector on https://prometheus.io/docs/prometheus/latest/querying/functions/ .
 	"changes":            newRollupFuncOneArg(rollupChanges),
 	"delta":              newRollupFuncOneArg(rollupDelta),
-	"deriv":              newRollupFuncOneArg(rollupDeriv),
+	"deriv":              newRollupFuncOneArg(rollupDerivSlow),
+	"deriv_fast":         newRollupFuncOneArg(rollupDerivFast),
 	"holt_winters":       newRollupHoltWinters,
 	"idelta":             newRollupFuncOneArg(rollupIdelta),
 	"increase":           newRollupFuncOneArg(rollupDelta),  // + rollupFuncsRemoveCounterResets
 	"irate":              newRollupFuncOneArg(rollupIderiv), // + rollupFuncsRemoveCounterResets
 	"predict_linear":     newRollupPredictLinear,
-	"rate":               newRollupFuncOneArg(rollupDeriv), // + rollupFuncsRemoveCounterResets
+	"rate":               newRollupFuncOneArg(rollupDerivFast), // + rollupFuncsRemoveCounterResets
 	"resets":             newRollupFuncOneArg(rollupResets),
 	"avg_over_time":      newRollupFuncOneArg(rollupAvg),
 	"min_over_time":      newRollupFuncOneArg(rollupMin),
@@ -37,6 +38,8 @@ var rollupFuncs = map[string]newRollupFunc{
 	"stdvar_over_time":   newRollupFuncOneArg(rollupStdvar),
 
 	// Additional rollup funcs.
+	"sum2_over_time":     newRollupFuncOneArg(rollupSum2),
+	"geomean_over_time":  newRollupFuncOneArg(rollupGeomean),
 	"first_over_time":    newRollupFuncOneArg(rollupFirst),
 	"last_over_time":     newRollupFuncOneArg(rollupLast),
 	"distinct_over_time": newRollupFuncOneArg(rollupDistinct),
@@ -47,6 +50,14 @@ var rollupFuncs = map[string]newRollupFunc{
 	"rollup_deriv":       newRollupFuncOneArg(rollupFake),
 	"rollup_delta":       newRollupFuncOneArg(rollupFake),
 	"rollup_increase":    newRollupFuncOneArg(rollupFake), // + rollupFuncsRemoveCounterResets
+	"rollup_candlestick": newRollupFuncOneArg(rollupFake),
+}
+
+var rollupFuncsMayAdjustWindow = map[string]bool{
+	"deriv":      true,
+	"deriv_fast": true,
+	"irate":      true,
+	"rate":       true,
 }
 
 var rollupFuncsRemoveCounterResets = map[string]bool{
@@ -64,6 +75,7 @@ var rollupFuncsKeepMetricGroup = map[string]bool{
 	"max_over_time":      true,
 	"quantile_over_time": true,
 	"rollup":             true,
+	"geomean_over_time":  true,
 }
 
 func getRollupArgIdx(funcName string) int {
@@ -120,6 +132,13 @@ type rollupConfig struct {
 	Step   int64
 	Window int64
 
+	// Whether window may be adjusted to 2 x interval between data points.
+	// This is needed for functions which have dt in the denominator
+	// such as rate, deriv, etc.
+	// Without the adjustement their value would jump in unexpected directions
+	// when using window smaller than 2 x scrape_interval.
+	MayAdjustWindow bool
+
 	Timestamps []int64
 }
 
@@ -162,7 +181,7 @@ func (rc *rollupConfig) Do(dstValues []float64, values []float64, timestamps []i
 	if window <= 0 {
 		window = rc.Step
 	}
-	if window < maxPrevInterval {
+	if rc.MayAdjustWindow && window < maxPrevInterval {
 		window = maxPrevInterval
 	}
 	rfa := getRollupFuncArg()
@@ -171,8 +190,7 @@ func (rc *rollupConfig) Do(dstValues []float64, values []float64, timestamps []i
 
 	i := 0
 	j := 0
-	for _, ts := range rc.Timestamps {
-		tEnd := ts + rc.Step
+	for _, tEnd := range rc.Timestamps {
 		tStart := tEnd - window
 		n := sort.Search(len(timestamps)-i, func(n int) bool {
 			return timestamps[i+n] > tStart
@@ -246,12 +264,14 @@ func deltaValues(values []float64) {
 	if len(values) == 0 {
 		return
 	}
+	prevDelta := float64(0)
 	prevValue := values[0]
 	for i, v := range values[1:] {
-		values[i] = v - prevValue
+		prevDelta = v - prevValue
+		values[i] = prevDelta
 		prevValue = v
 	}
-	values[len(values)-1] = nan
+	values[len(values)-1] = prevDelta
 }
 
 func derivValues(values []float64, timestamps []int64) {
@@ -260,16 +280,23 @@ func derivValues(values []float64, timestamps []int64) {
 	if len(values) == 0 {
 		return
 	}
+	prevDeriv := float64(0)
 	prevValue := values[0]
 	prevTs := timestamps[0]
 	for i, v := range values[1:] {
 		ts := timestamps[i+1]
+		if ts == prevTs {
+			// Use the previous value for duplicate timestamps.
+			values[i] = prevDeriv
+			continue
+		}
 		dt := float64(ts-prevTs) * 1e-3
-		values[i] = (v - prevValue) / dt
+		prevDeriv = (v - prevValue) / dt
+		values[i] = prevDeriv
 		prevValue = v
 		prevTs = ts
 	}
-	values[len(values)-1] = nan
+	values[len(values)-1] = prevDeriv
 }
 
 type newRollupFunc func(args []interface{}) (rollupFunc, error)
@@ -296,11 +323,11 @@ func newRollupHoltWinters(args []interface{}) (rollupFunc, error) {
 		return nil, err
 	}
 	rf := func(rfa *rollupFuncArg) float64 {
-		// There is no need in handling NaNs here, since they must be cleanup up
+		// There is no need in handling NaNs here, since they must be cleaned up
 		// before calling rollup funcs.
 		values := rfa.values
 		if len(values) == 0 {
-			return nan
+			return rfa.prevValue
 		}
 		sf := sfs[rfa.idx]
 		if sf <= 0 || sf >= 1 {
@@ -342,41 +369,55 @@ func newRollupPredictLinear(args []interface{}) (rollupFunc, error) {
 		return nil, err
 	}
 	rf := func(rfa *rollupFuncArg) float64 {
-		// There is no need in handling NaNs here, since they must be cleanup up
-		// before calling rollup funcs.
-		values := rfa.values
-		timestamps := rfa.timestamps
-		if len(values) == 0 {
+		v, k := linearRegression(rfa)
+		if math.IsNaN(v) {
 			return nan
 		}
-
-		// See https://en.wikipedia.org/wiki/Simple_linear_regression#Numerical_example
-		// TODO: determine whether this shit really works.
-		tFirst := rfa.prevTimestamp
-		vSum := rfa.prevValue
-		if math.IsNaN(rfa.prevValue) {
-			tFirst = timestamps[0]
-			vSum = 0
-		}
-		tSum := float64(0)
-		tvSum := float64(0)
-		ttSum := float64(0)
-		for i, v := range values {
-			dt := float64(timestamps[i]-tFirst) * 1e-3
-			vSum += v
-			tSum += dt
-			tvSum += dt * v
-			ttSum += dt * dt
-		}
-		n := float64(len(values))
-		k := (n*tvSum - tSum*vSum) / (n*ttSum - tSum*tSum)
-		v := (vSum - k*tSum) / n
 		sec := secs[rfa.idx]
 		return v + k*sec
 	}
 	return rf, nil
 }
 
+func linearRegression(rfa *rollupFuncArg) (float64, float64) {
+	// There is no need in handling NaNs here, since they must be cleaned up
+	// before calling rollup funcs.
+	values := rfa.values
+	timestamps := rfa.timestamps
+	if len(values) == 0 {
+		return rfa.prevValue, 0
+	}
+
+	// See https://en.wikipedia.org/wiki/Simple_linear_regression#Numerical_example
+	tFirst := rfa.prevTimestamp
+	vSum := rfa.prevValue
+	tSum := float64(0)
+	tvSum := float64(0)
+	ttSum := float64(0)
+	n := 1.0
+	if math.IsNaN(rfa.prevValue) {
+		tFirst = timestamps[0]
+		vSum = 0
+		n = 0
+	}
+	for i, v := range values {
+		dt := float64(timestamps[i]-tFirst) * 1e-3
+		vSum += v
+		tSum += dt
+		tvSum += dt * v
+		ttSum += dt * dt
+	}
+	n += float64(len(values))
+	if n == 1 {
+		return vSum, 0
+	}
+	k := (n*tvSum - tSum*vSum) / (n*ttSum - tSum*tSum)
+	v := (vSum - k*tSum) / n
+	// Adjust v to the last timestamp on the given time range.
+	v += k * (float64(timestamps[len(timestamps)-1]-tFirst) * 1e-3)
+	return v, k
+}
+
 func newRollupQuantile(args []interface{}) (rollupFunc, error) {
 	if err := expectRollupArgsNum(args, 2); err != nil {
 		return nil, err
@@ -386,11 +427,15 @@ func newRollupQuantile(args []interface{}) (rollupFunc, error) {
 		return nil, err
 	}
 	rf := func(rfa *rollupFuncArg) float64 {
-		// There is no need in handling NaNs here, since they must be cleanup up
+		// There is no need in handling NaNs here, since they must be cleaned up
 		// before calling rollup funcs.
 		values := rfa.values
 		if len(values) == 0 {
-			return nan
+			return rfa.prevValue
+		}
+		if len(values) == 1 {
+			// Fast path - only a single value.
+			return values[0]
 		}
 		hf := histogram.GetFast()
 		for _, v := range values {
@@ -408,11 +453,11 @@ func rollupAvg(rfa *rollupFuncArg) float64 {
 	// Do not use `Rapid calculation methods` at https://en.wikipedia.org/wiki/Standard_deviation,
 	// since it is slower and has no significant benefits in precision.
 
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
-		return nan
+		return rfa.prevValue
 	}
 	var sum float64
 	for _, v := range values {
@@ -422,11 +467,11 @@ func rollupAvg(rfa *rollupFuncArg) float64 {
 }
 
 func rollupMin(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
-		return nan
+		return rfa.prevValue
 	}
 	minValue := values[0]
 	for _, v := range values {
@@ -438,11 +483,11 @@ func rollupMin(rfa *rollupFuncArg) float64 {
 }
 
 func rollupMax(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
-		return nan
+		return rfa.prevValue
 	}
 	maxValue := values[0]
 	for _, v := range values {
@@ -454,11 +499,11 @@ func rollupMax(rfa *rollupFuncArg) float64 {
 }
 
 func rollupSum(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
-		return nan
+		return rfa.prevValue
 	}
 	var sum float64
 	for _, v := range values {
@@ -467,12 +512,43 @@ func rollupSum(rfa *rollupFuncArg) float64 {
 	return sum
 }
 
-func rollupCount(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+func rollupSum2(rfa *rollupFuncArg) float64 {
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
-		return nan
+		return rfa.prevValue * rfa.prevValue
+	}
+	var sum2 float64
+	for _, v := range values {
+		sum2 += v * v
+	}
+	return sum2
+}
+
+func rollupGeomean(rfa *rollupFuncArg) float64 {
+	// There is no need in handling NaNs here, since they must be cleaned up
+	// before calling rollup funcs.
+	values := rfa.values
+	if len(values) == 0 {
+		return rfa.prevValue
+	}
+	p := 1.0
+	for _, v := range values {
+		p *= v
+	}
+	return math.Pow(p, 1/float64(len(values)))
+}
+
+func rollupCount(rfa *rollupFuncArg) float64 {
+	// There is no need in handling NaNs here, since they must be cleaned up
+	// before calling rollup funcs.
+	values := rfa.values
+	if len(values) == 0 {
+		if math.IsNaN(rfa.prevValue) {
+			return nan
+		}
+		return 0
 	}
 	return float64(len(values))
 }
@@ -485,11 +561,18 @@ func rollupStddev(rfa *rollupFuncArg) float64 {
 func rollupStdvar(rfa *rollupFuncArg) float64 {
 	// See `Rapid calculation methods` at https://en.wikipedia.org/wiki/Standard_deviation
 
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
-		return nan
+		if math.IsNaN(rfa.prevValue) {
+			return nan
+		}
+		return 0
+	}
+	if len(values) == 1 {
+		// Fast path.
+		return values[0]
 	}
 	var avg float64
 	var count float64
@@ -504,7 +587,7 @@ func rollupStdvar(rfa *rollupFuncArg) float64 {
 }
 
 func rollupDelta(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	prevValue := rfa.prevValue
@@ -516,32 +599,42 @@ func rollupDelta(rfa *rollupFuncArg) float64 {
 		values = values[1:]
 	}
 	if len(values) == 0 {
-		return nan
+		return 0
 	}
 	return values[len(values)-1] - prevValue
 }
 
 func rollupIdelta(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
-		return nan
+		if math.IsNaN(rfa.prevValue) {
+			return nan
+		}
+		return 0
 	}
 	lastValue := values[len(values)-1]
 	values = values[:len(values)-1]
 	if len(values) == 0 {
 		prevValue := rfa.prevValue
 		if math.IsNaN(prevValue) {
-			return nan
+			return 0
 		}
 		return lastValue - prevValue
 	}
 	return lastValue - values[len(values)-1]
 }
 
-func rollupDeriv(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+func rollupDerivSlow(rfa *rollupFuncArg) float64 {
+	// Use linear regression like Prometheus does.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/73
+	_, k := linearRegression(rfa)
+	return k
+}
+
+func rollupDerivFast(rfa *rollupFuncArg) float64 {
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	timestamps := rfa.timestamps
@@ -557,7 +650,7 @@ func rollupDeriv(rfa *rollupFuncArg) float64 {
 		timestamps = timestamps[1:]
 	}
 	if len(values) == 0 {
-		return nan
+		return 0
 	}
 	vEnd := values[len(values)-1]
 	tEnd := timestamps[len(timestamps)-1]
@@ -567,43 +660,54 @@ func rollupDeriv(rfa *rollupFuncArg) float64 {
 }
 
 func rollupIderiv(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	timestamps := rfa.timestamps
 	if len(values) == 0 {
-		return nan
+		if math.IsNaN(rfa.prevValue) {
+			return nan
+		}
+		return 0
 	}
 	vEnd := values[len(values)-1]
 	tEnd := timestamps[len(timestamps)-1]
 	values = values[:len(values)-1]
 	timestamps = timestamps[:len(timestamps)-1]
-	prevValue := rfa.prevValue
-	prevTimestamp := rfa.prevTimestamp
-	if len(values) == 0 {
-		if math.IsNaN(prevValue) {
-			return nan
-		}
-	} else {
-		prevValue = values[len(values)-1]
-		prevTimestamp = timestamps[len(timestamps)-1]
+	// Skip data points with duplicate timestamps.
+	for len(timestamps) > 0 && timestamps[len(timestamps)-1] >= tEnd {
+		timestamps = timestamps[:len(timestamps)-1]
 	}
-	dv := vEnd - prevValue
-	dt := tEnd - prevTimestamp
+	var tStart int64
+	var vStart float64
+	if len(timestamps) == 0 {
+		if math.IsNaN(rfa.prevValue) {
+			return 0
+		}
+		tStart = rfa.prevTimestamp
+		vStart = rfa.prevValue
+	} else {
+		tStart = timestamps[len(timestamps)-1]
+		vStart = values[len(timestamps)-1]
+	}
+	dv := vEnd - vStart
+	dt := tEnd - tStart
 	return dv / (float64(dt) / 1000)
 }
 
 func rollupChanges(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
-	if len(values) == 0 {
-		return nan
-	}
-	n := 0
 	prevValue := rfa.prevValue
+	n := 0
 	if math.IsNaN(prevValue) {
+		if len(values) == 0 {
+			return nan
+		}
 		prevValue = values[0]
+		values = values[1:]
+		n++
 	}
 	for _, v := range values {
 		if v != prevValue {
@@ -615,11 +719,14 @@ func rollupChanges(rfa *rollupFuncArg) float64 {
 }
 
 func rollupResets(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
-		return nan
+		if math.IsNaN(rfa.prevValue) {
+			return nan
+		}
+		return 0
 	}
 	prevValue := rfa.prevValue
 	if math.IsNaN(prevValue) {
@@ -627,7 +734,7 @@ func rollupResets(rfa *rollupFuncArg) float64 {
 		values = values[1:]
 	}
 	if len(values) == 0 {
-		return nan
+		return 0
 	}
 	n := 0
 	for _, v := range values {
@@ -646,7 +753,7 @@ func rollupFirst(rfa *rollupFuncArg) float64 {
 		return v
 	}
 
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
@@ -655,24 +762,27 @@ func rollupFirst(rfa *rollupFuncArg) float64 {
 	return values[0]
 }
 
-var rollupDefault = rollupFirst
+var rollupDefault = rollupLast
 
 func rollupLast(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
-		return nan
+		return rfa.prevValue
 	}
 	return values[len(values)-1]
 }
 
 func rollupDistinct(rfa *rollupFuncArg) float64 {
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
-		return nan
+		if math.IsNaN(rfa.prevValue) {
+			return nan
+		}
+		return 0
 	}
 	m := make(map[float64]struct{})
 	for _, v := range values {
@@ -684,12 +794,15 @@ func rollupDistinct(rfa *rollupFuncArg) float64 {
 func rollupIntegrate(rfa *rollupFuncArg) float64 {
 	prevTimestamp := rfa.prevTimestamp
 
-	// There is no need in handling NaNs here, since they must be cleanup up
+	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
 	values := rfa.values
 	timestamps := rfa.timestamps
 	if len(values) == 0 {
-		return nan
+		if math.IsNaN(rfa.prevValue) {
+			return nan
+		}
+		return 0
 	}
 	prevValue := rfa.prevValue
 	if math.IsNaN(prevValue) {
@@ -699,7 +812,7 @@ func rollupIntegrate(rfa *rollupFuncArg) float64 {
 		timestamps = timestamps[1:]
 	}
 	if len(values) == 0 {
-		return nan
+		return 0
 	}
 
 	var sum float64

app/vmselect/promql/rollup_result_cache.go

@@ -2,6 +2,7 @@ package promql
 
 import (
 	"crypto/rand"
+	"flag"
 	"fmt"
 	"runtime"
 	"sync"
@@ -15,6 +16,8 @@ import (
 	"github.com/VictoriaMetrics/metrics"
 )
 
+var disableCache = flag.Bool("search.disableCache", false, "Whether to disable response caching. This may be useful during data backfilling")
+
 var rollupResultCacheV = &rollupResultCache{
 	fastcache.New(1024 * 1024), // This is a cache for testing.
 }
@@ -47,6 +50,10 @@ func InitRollupResultCache(cachePath string) {
 	} else {
 		c = fastcache.New(getRollupResultCacheSize())
 	}
+	if *disableCache {
+		c.Reset()
+	}
+
 	stats := &fastcache.Stats{}
 	var statsLock sync.Mutex
 	var statsLastUpdate time.Time
@@ -64,7 +71,7 @@ func InitRollupResultCache(cachePath string) {
 		return stats
 	}
 	if len(rollupResultCachePath) > 0 {
-		logger.Infof("loaded rollupResult cache from %q in %s; entriesCount: %d, bytesSize: %d",
+		logger.Infof("loaded rollupResult cache from %q in %s; entriesCount: %d, sizeBytes: %d",
 			rollupResultCachePath, time.Since(startTime), fcs().EntriesCount, fcs().BytesSize)
 	}
 
@@ -101,7 +108,7 @@ func StopRollupResultCache() {
 		var fcs fastcache.Stats
 		rollupResultCacheV.c.UpdateStats(&fcs)
 		rollupResultCacheV.c.Reset()
-		logger.Infof("saved rollupResult cache to %q in %s; entriesCount: %d, bytesSize: %d",
+		logger.Infof("saved rollupResult cache to %q in %s; entriesCount: %d, sizeBytes: %d",
 			rollupResultCachePath, time.Since(startTime), fcs.EntriesCount, fcs.BytesSize)
 	}
 }
@@ -118,8 +125,8 @@ func ResetRollupResultCache() {
 	rollupResultCacheV.c.Reset()
 }
 
-func (rrc *rollupResultCache) Get(funcName string, ec *EvalConfig, me *metricExpr, window int64) (tss []*timeseries, newStart int64) {
-	if !ec.mayCache() {
+func (rrc *rollupResultCache) Get(funcName string, ec *EvalConfig, me *metricExpr, iafc *incrementalAggrFuncContext, window int64) (tss []*timeseries, newStart int64) {
+	if *disableCache || !ec.mayCache() {
 		return nil, ec.Start
 	}
 
@@ -127,7 +134,7 @@ func (rrc *rollupResultCache) Get(funcName string, ec *EvalConfig, me *metricExp
 	bb := bbPool.Get()
 	defer bbPool.Put(bb)
 
-	bb.B = marshalRollupResultCacheKey(bb.B[:0], funcName, me, window, ec.Step)
+	bb.B = marshalRollupResultCacheKey(bb.B[:0], funcName, me, iafc, window, ec.Step)
 	metainfoBuf := rrc.c.Get(nil, bb.B)
 	if len(metainfoBuf) == 0 {
 		return nil, ec.Start
@@ -145,7 +152,7 @@ func (rrc *rollupResultCache) Get(funcName string, ec *EvalConfig, me *metricExp
 	if len(resultBuf) == 0 {
 		mi.RemoveKey(key)
 		metainfoBuf = mi.Marshal(metainfoBuf[:0])
-		bb.B = marshalRollupResultCacheKey(bb.B[:0], funcName, me, window, ec.Step)
+		bb.B = marshalRollupResultCacheKey(bb.B[:0], funcName, me, iafc, window, ec.Step)
 		rrc.c.Set(bb.B, metainfoBuf)
 		return nil, ec.Start
 	}
@@ -189,8 +196,8 @@ func (rrc *rollupResultCache) Get(funcName string, ec *EvalConfig, me *metricExp
 	return tss, newStart
 }
 
-func (rrc *rollupResultCache) Put(funcName string, ec *EvalConfig, me *metricExpr, window int64, tss []*timeseries) {
-	if len(tss) == 0 || !ec.mayCache() {
+func (rrc *rollupResultCache) Put(funcName string, ec *EvalConfig, me *metricExpr, iafc *incrementalAggrFuncContext, window int64, tss []*timeseries) {
+	if *disableCache || len(tss) == 0 || !ec.mayCache() {
 		return
 	}
 
@@ -235,7 +242,7 @@ func (rrc *rollupResultCache) Put(funcName string, ec *EvalConfig, me *metricExp
 	bb.B = key.Marshal(bb.B[:0])
 	rrc.c.SetBig(bb.B, tssMarshaled)
 
-	bb.B = marshalRollupResultCacheKey(bb.B[:0], funcName, me, window, ec.Step)
+	bb.B = marshalRollupResultCacheKey(bb.B[:0], funcName, me, iafc, window, ec.Step)
 	metainfoBuf := rrc.c.Get(nil, bb.B)
 	var mi rollupResultCacheMetainfo
 	if len(metainfoBuf) > 0 {
@@ -263,10 +270,16 @@ var (
 var tooBigRollupResults = metrics.NewCounter("vm_too_big_rollup_results_total")
 
 // Increment this value every time the format of the cache changes.
-const rollupResultCacheVersion = 4
+const rollupResultCacheVersion = 5
 
-func marshalRollupResultCacheKey(dst []byte, funcName string, me *metricExpr, window, step int64) []byte {
+func marshalRollupResultCacheKey(dst []byte, funcName string, me *metricExpr, iafc *incrementalAggrFuncContext, window, step int64) []byte {
 	dst = append(dst, rollupResultCacheVersion)
+	if iafc == nil {
+		dst = append(dst, 0)
+	} else {
+		dst = append(dst, 1)
+		dst = iafc.ae.AppendString(dst)
+	}
 	dst = encoding.MarshalUint64(dst, uint64(len(funcName)))
 	dst = append(dst, funcName...)
 	dst = encoding.MarshalInt64(dst, window)

app/vmselect/promql/rollup_result_cache_test.go

@@ -23,10 +23,15 @@ func TestRollupResultCache(t *testing.T) {
 			Value: []byte("xxx"),
 		}},
 	}
+	iafc := &incrementalAggrFuncContext{
+		ae: &aggrFuncExpr{
+			Name: "foobar",
+		},
+	}
 
 	// Try obtaining an empty value.
 	t.Run("empty", func(t *testing.T) {
-		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, window)
+		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, nil, window)
 		if newStart != ec.Start {
 			t.Fatalf("unexpected newStart; got %d; want %d", newStart, ec.Start)
 		}
@@ -36,21 +41,42 @@ func TestRollupResultCache(t *testing.T) {
 	})
 
 	// Store timeseries overlapping with start
-	t.Run("start-overlap", func(t *testing.T) {
+	t.Run("start-overlap-no-iafc", func(t *testing.T) {
 		ResetRollupResultCache()
 		tss := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{800, 1000, 1200},
 				Values:     []float64{0, 1, 2},
 			},
 		}
-		rollupResultCacheV.Put(funcName, ec, me, window, tss)
-		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, window)
+		rollupResultCacheV.Put(funcName, ec, me, nil, window, tss)
+		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, nil, window)
 		if newStart != 1400 {
 			t.Fatalf("unexpected newStart; got %d; want %d", newStart, 1400)
 		}
 		tssExpected := []*timeseries{
-			&timeseries{
+			{
+				Timestamps: []int64{1000, 1200},
+				Values:     []float64{1, 2},
+			},
+		}
+		testTimeseriesEqual(t, tss, tssExpected)
+	})
+	t.Run("start-overlap-with-iafc", func(t *testing.T) {
+		ResetRollupResultCache()
+		tss := []*timeseries{
+			{
+				Timestamps: []int64{800, 1000, 1200},
+				Values:     []float64{0, 1, 2},
+			},
+		}
+		rollupResultCacheV.Put(funcName, ec, me, iafc, window, tss)
+		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, iafc, window)
+		if newStart != 1400 {
+			t.Fatalf("unexpected newStart; got %d; want %d", newStart, 1400)
+		}
+		tssExpected := []*timeseries{
+			{
 				Timestamps: []int64{1000, 1200},
 				Values:     []float64{1, 2},
 			},
@@ -62,13 +88,13 @@ func TestRollupResultCache(t *testing.T) {
 	t.Run("end-overlap", func(t *testing.T) {
 		ResetRollupResultCache()
 		tss := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1800, 2000, 2200, 2400},
 				Values:     []float64{333, 0, 1, 2},
 			},
 		}
-		rollupResultCacheV.Put(funcName, ec, me, window, tss)
-		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, window)
+		rollupResultCacheV.Put(funcName, ec, me, nil, window, tss)
+		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, nil, window)
 		if newStart != 1000 {
 			t.Fatalf("unexpected newStart; got %d; want %d", newStart, 1000)
 		}
@@ -81,13 +107,13 @@ func TestRollupResultCache(t *testing.T) {
 	t.Run("full-cover", func(t *testing.T) {
 		ResetRollupResultCache()
 		tss := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1200, 1400, 1600},
 				Values:     []float64{0, 1, 2},
 			},
 		}
-		rollupResultCacheV.Put(funcName, ec, me, window, tss)
-		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, window)
+		rollupResultCacheV.Put(funcName, ec, me, nil, window, tss)
+		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, nil, window)
 		if newStart != 1000 {
 			t.Fatalf("unexpected newStart; got %d; want %d", newStart, 1000)
 		}
@@ -100,13 +126,13 @@ func TestRollupResultCache(t *testing.T) {
 	t.Run("before-start", func(t *testing.T) {
 		ResetRollupResultCache()
 		tss := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{200, 400, 600},
 				Values:     []float64{0, 1, 2},
 			},
 		}
-		rollupResultCacheV.Put(funcName, ec, me, window, tss)
-		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, window)
+		rollupResultCacheV.Put(funcName, ec, me, nil, window, tss)
+		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, nil, window)
 		if newStart != 1000 {
 			t.Fatalf("unexpected newStart; got %d; want %d", newStart, 1000)
 		}
@@ -119,13 +145,13 @@ func TestRollupResultCache(t *testing.T) {
 	t.Run("after-end", func(t *testing.T) {
 		ResetRollupResultCache()
 		tss := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{2200, 2400, 2600},
 				Values:     []float64{0, 1, 2},
 			},
 		}
-		rollupResultCacheV.Put(funcName, ec, me, window, tss)
-		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, window)
+		rollupResultCacheV.Put(funcName, ec, me, nil, window, tss)
+		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, nil, window)
 		if newStart != 1000 {
 			t.Fatalf("unexpected newStart; got %d; want %d", newStart, 1000)
 		}
@@ -138,18 +164,18 @@ func TestRollupResultCache(t *testing.T) {
 	t.Run("bigger-than-start-end", func(t *testing.T) {
 		ResetRollupResultCache()
 		tss := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{800, 1000, 1200, 1400, 1600, 1800, 2000, 2200},
 				Values:     []float64{0, 1, 2, 3, 4, 5, 6, 7},
 			},
 		}
-		rollupResultCacheV.Put(funcName, ec, me, window, tss)
-		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, window)
+		rollupResultCacheV.Put(funcName, ec, me, nil, window, tss)
+		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, nil, window)
 		if newStart != 2200 {
 			t.Fatalf("unexpected newStart; got %d; want %d", newStart, 2200)
 		}
 		tssExpected := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200, 1400, 1600, 1800, 2000},
 				Values:     []float64{1, 2, 3, 4, 5, 6},
 			},
@@ -161,18 +187,18 @@ func TestRollupResultCache(t *testing.T) {
 	t.Run("start-end-match", func(t *testing.T) {
 		ResetRollupResultCache()
 		tss := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200, 1400, 1600, 1800, 2000},
 				Values:     []float64{1, 2, 3, 4, 5, 6},
 			},
 		}
-		rollupResultCacheV.Put(funcName, ec, me, window, tss)
-		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, window)
+		rollupResultCacheV.Put(funcName, ec, me, nil, window, tss)
+		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, nil, window)
 		if newStart != 2200 {
 			t.Fatalf("unexpected newStart; got %d; want %d", newStart, 2200)
 		}
 		tssExpected := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200, 1400, 1600, 1800, 2000},
 				Values:     []float64{1, 2, 3, 4, 5, 6},
 			},
@@ -191,8 +217,8 @@ func TestRollupResultCache(t *testing.T) {
 			}
 			tss = append(tss, ts)
 		}
-		rollupResultCacheV.Put(funcName, ec, me, window, tss)
-		tssResult, newStart := rollupResultCacheV.Get(funcName, ec, me, window)
+		rollupResultCacheV.Put(funcName, ec, me, nil, window, tss)
+		tssResult, newStart := rollupResultCacheV.Get(funcName, ec, me, nil, window)
 		if newStart != 2200 {
 			t.Fatalf("unexpected newStart; got %d; want %d", newStart, 2200)
 		}
@@ -203,32 +229,32 @@ func TestRollupResultCache(t *testing.T) {
 	t.Run("multi-timeseries", func(t *testing.T) {
 		ResetRollupResultCache()
 		tss1 := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{800, 1000, 1200},
 				Values:     []float64{0, 1, 2},
 			},
 		}
 		tss2 := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1800, 2000, 2200, 2400},
 				Values:     []float64{333, 0, 1, 2},
 			},
 		}
 		tss3 := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1200, 1400, 1600},
 				Values:     []float64{0, 1, 2},
 			},
 		}
-		rollupResultCacheV.Put(funcName, ec, me, window, tss1)
-		rollupResultCacheV.Put(funcName, ec, me, window, tss2)
-		rollupResultCacheV.Put(funcName, ec, me, window, tss3)
-		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, window)
+		rollupResultCacheV.Put(funcName, ec, me, nil, window, tss1)
+		rollupResultCacheV.Put(funcName, ec, me, nil, window, tss2)
+		rollupResultCacheV.Put(funcName, ec, me, nil, window, tss3)
+		tss, newStart := rollupResultCacheV.Get(funcName, ec, me, nil, window)
 		if newStart != 1400 {
 			t.Fatalf("unexpected newStart; got %d; want %d", newStart, 1400)
 		}
 		tssExpected := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200},
 				Values:     []float64{1, 2},
 			},
@@ -249,14 +275,14 @@ func TestMergeTimeseries(t *testing.T) {
 	t.Run("bStart=ec.Start", func(t *testing.T) {
 		a := []*timeseries{}
 		b := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200, 1400, 1600, 1800, 2000},
 				Values:     []float64{1, 2, 3, 4, 5, 6},
 			},
 		}
 		tss := mergeTimeseries(a, b, 1000, ec)
 		tssExpected := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200, 1400, 1600, 1800, 2000},
 				Values:     []float64{1, 2, 3, 4, 5, 6},
 			},
@@ -266,14 +292,14 @@ func TestMergeTimeseries(t *testing.T) {
 	t.Run("a-empty", func(t *testing.T) {
 		a := []*timeseries{}
 		b := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1400, 1600, 1800, 2000},
 				Values:     []float64{3, 4, 5, 6},
 			},
 		}
 		tss := mergeTimeseries(a, b, bStart, ec)
 		tssExpected := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200, 1400, 1600, 1800, 2000},
 				Values:     []float64{nan, nan, 3, 4, 5, 6},
 			},
@@ -282,7 +308,7 @@ func TestMergeTimeseries(t *testing.T) {
 	})
 	t.Run("b-empty", func(t *testing.T) {
 		a := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200},
 				Values:     []float64{2, 1},
 			},
@@ -290,7 +316,7 @@ func TestMergeTimeseries(t *testing.T) {
 		b := []*timeseries{}
 		tss := mergeTimeseries(a, b, bStart, ec)
 		tssExpected := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200, 1400, 1600, 1800, 2000},
 				Values:     []float64{2, 1, nan, nan, nan, nan},
 			},
@@ -299,20 +325,20 @@ func TestMergeTimeseries(t *testing.T) {
 	})
 	t.Run("non-empty", func(t *testing.T) {
 		a := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200},
 				Values:     []float64{2, 1},
 			},
 		}
 		b := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1400, 1600, 1800, 2000},
 				Values:     []float64{3, 4, 5, 6},
 			},
 		}
 		tss := mergeTimeseries(a, b, bStart, ec)
 		tssExpected := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200, 1400, 1600, 1800, 2000},
 				Values:     []float64{2, 1, 3, 4, 5, 6},
 			},
@@ -321,14 +347,14 @@ func TestMergeTimeseries(t *testing.T) {
 	})
 	t.Run("non-empty-distinct-metric-names", func(t *testing.T) {
 		a := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1000, 1200},
 				Values:     []float64{2, 1},
 			},
 		}
 		a[0].MetricName.MetricGroup = []byte("bar")
 		b := []*timeseries{
-			&timeseries{
+			{
 				Timestamps: []int64{1400, 1600, 1800, 2000},
 				Values:     []float64{3, 4, 5, 6},
 			},
@@ -336,14 +362,14 @@ func TestMergeTimeseries(t *testing.T) {
 		b[0].MetricName.MetricGroup = []byte("foo")
 		tss := mergeTimeseries(a, b, bStart, ec)
 		tssExpected := []*timeseries{
-			&timeseries{
+			{
 				MetricName: storage.MetricName{
 					MetricGroup: []byte("foo"),
 				},
 				Timestamps: []int64{1000, 1200, 1400, 1600, 1800, 2000},
 				Values:     []float64{nan, nan, 3, 4, 5, 6},
 			},
-			&timeseries{
+			{
 				MetricName: storage.MetricName{
 					MetricGroup: []byte("bar"),
 				},

app/vmselect/promql/rollup_test.go

@@ -10,6 +10,68 @@ var (
 	testTimestamps = []int64{5, 15, 24, 36, 49, 60, 78, 80, 97, 115, 120, 130}
 )
 
+func TestRollupIderivDuplicateTimestamps(t *testing.T) {
+	rfa := &rollupFuncArg{
+		values:     []float64{1, 2, 3, 4, 5},
+		timestamps: []int64{100, 100, 200, 300, 300},
+	}
+	n := rollupIderiv(rfa)
+	if n != 20 {
+		t.Fatalf("unexpected value; got %v; want %v", n, 20)
+	}
+
+	rfa = &rollupFuncArg{
+		values:     []float64{1, 2, 3, 4, 5},
+		timestamps: []int64{100, 100, 300, 300, 300},
+	}
+	n = rollupIderiv(rfa)
+	if n != 15 {
+		t.Fatalf("unexpected value; got %v; want %v", n, 15)
+	}
+
+	rfa = &rollupFuncArg{
+		prevValue:  nan,
+		values:     []float64{},
+		timestamps: []int64{},
+	}
+	n = rollupIderiv(rfa)
+	if !math.IsNaN(n) {
+		t.Fatalf("unexpected value; got %v; want %v", n, nan)
+	}
+
+	rfa = &rollupFuncArg{
+		prevValue:  nan,
+		values:     []float64{15},
+		timestamps: []int64{100},
+	}
+	n = rollupIderiv(rfa)
+	if n != 0 {
+		t.Fatalf("unexpected value; got %v; want %v", n, 0)
+	}
+
+	rfa = &rollupFuncArg{
+		prevTimestamp: 100,
+		prevValue:     10,
+		values:        []float64{15},
+		timestamps:    []int64{100},
+	}
+	n = rollupIderiv(rfa)
+	if n != inf {
+		t.Fatalf("unexpected value; got %v; want %v", n, inf)
+	}
+
+	rfa = &rollupFuncArg{
+		prevTimestamp: 100,
+		prevValue:     10,
+		values:        []float64{15, 20},
+		timestamps:    []int64{100, 100},
+	}
+	n = rollupIderiv(rfa)
+	if n != inf {
+		t.Fatalf("unexpected value; got %v; want %v", n, inf)
+	}
+}
+
 func TestRemoveCounterResets(t *testing.T) {
 	removeCounterResets(nil)
 
@@ -38,19 +100,19 @@ func TestDeltaValues(t *testing.T) {
 
 	values := []float64{123}
 	deltaValues(values)
-	valuesExpected := []float64{nan}
+	valuesExpected := []float64{0}
 	testRowsEqual(t, values, testTimestamps[:1], valuesExpected, testTimestamps[:1])
 
 	values = append([]float64{}, testValues...)
 	deltaValues(values)
-	valuesExpected = []float64{-89, 10, -23, 33, -20, 65, -87, 32, -12, 2, 0, nan}
+	valuesExpected = []float64{-89, 10, -23, 33, -20, 65, -87, 32, -12, 2, 0, 0}
 	testRowsEqual(t, values, testTimestamps, valuesExpected, testTimestamps)
 
 	// remove counter resets
 	values = append([]float64{}, testValues...)
 	removeCounterResets(values)
 	deltaValues(values)
-	valuesExpected = []float64{34, 10, 21, 33, 34, 65, 12, 32, 32, 2, 0, nan}
+	valuesExpected = []float64{34, 10, 21, 33, 34, 65, 12, 32, 32, 2, 0, 0}
 	testRowsEqual(t, values, testTimestamps, valuesExpected, testTimestamps)
 }
 
@@ -59,13 +121,13 @@ func TestDerivValues(t *testing.T) {
 
 	values := []float64{123}
 	derivValues(values, testTimestamps[:1])
-	valuesExpected := []float64{nan}
+	valuesExpected := []float64{0}
 	testRowsEqual(t, values, testTimestamps[:1], valuesExpected, testTimestamps[:1])
 
 	values = append([]float64{}, testValues...)
 	derivValues(values, testTimestamps)
 	valuesExpected = []float64{-8900, 1111.111111111111, -1916.6666666666665, 2538.461538461538, -1818.1818181818182, 3611.111111111111,
-		-43500, 1882.3529411764705, -666.6666666666666, 400, 0, nan}
+		-43500, 1882.3529411764705, -666.6666666666666, 400, 0, 0}
 	testRowsEqual(t, values, testTimestamps, valuesExpected, testTimestamps)
 
 	// remove counter resets
@@ -73,8 +135,15 @@ func TestDerivValues(t *testing.T) {
 	removeCounterResets(values)
 	derivValues(values, testTimestamps)
 	valuesExpected = []float64{3400, 1111.111111111111, 1750, 2538.461538461538, 3090.909090909091, 3611.111111111111,
-		6000, 1882.3529411764705, 1777.7777777777776, 400, 0, nan}
+		6000, 1882.3529411764705, 1777.7777777777776, 400, 0, 0}
 	testRowsEqual(t, values, testTimestamps, valuesExpected, testTimestamps)
+
+	// duplicate timestamps
+	values = []float64{1, 2, 3, 4, 5, 6, 7}
+	timestamps := []int64{100, 100, 200, 200, 300, 400, 400}
+	derivValues(values, timestamps)
+	valuesExpected = []float64{0, 20, 20, 20, 10, 10, 10}
+	testRowsEqual(t, values, timestamps, valuesExpected, timestamps)
 }
 
 func testRollupFunc(t *testing.T, funcName string, args []interface{}, meExpected *metricExpr, vExpected float64) {
@@ -143,10 +212,10 @@ func TestRollupPredictLinear(t *testing.T) {
 		testRollupFunc(t, "predict_linear", args, &me, vExpected)
 	}
 
-	f(0e-3, 63.739757761102624)
-	f(50e-3, 50.39682764539959)
-	f(100e-3, 37.053897529696556)
-	f(200e-3, 10.368037298290488)
+	f(0e-3, 30.382432471845043)
+	f(50e-3, 17.03950235614201)
+	f(100e-3, 3.696572240438975)
+	f(200e-3, -22.989287990967092)
 }
 
 func TestRollupHoltWinters(t *testing.T) {
@@ -189,10 +258,11 @@ func TestRollupNewRollupFuncSuccess(t *testing.T) {
 		testRollupFunc(t, funcName, args, &me, vExpected)
 	}
 
-	f("default_rollup", 123)
-	f("changes", 10)
+	f("default_rollup", 34)
+	f("changes", 11)
 	f("delta", -89)
-	f("deriv", -712)
+	f("deriv", -266.85860231406065)
+	f("deriv_fast", -712)
 	f("idelta", 0)
 	f("increase", 275)
 	f("irate", 0)
@@ -202,12 +272,16 @@ func TestRollupNewRollupFuncSuccess(t *testing.T) {
 	f("min_over_time", 12)
 	f("max_over_time", 123)
 	f("sum_over_time", 565)
+	f("sum2_over_time", 37951)
+	f("geomean_over_time", 39.33466603189148)
 	f("count_over_time", 12)
 	f("stddev_over_time", 30.752935722554287)
 	f("stdvar_over_time", 945.7430555555555)
 	f("first_over_time", 123)
 	f("last_over_time", 34)
 	f("integrate", 61.0275)
+	f("distinct_over_time", 8)
+	f("ideriv", 0)
 }
 
 func TestRollupNewRollupFuncError(t *testing.T) {
@@ -259,7 +333,7 @@ func TestRollupNoWindowNoPoints(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{nan, nan, nan, nan, 123}
+		valuesExpected := []float64{nan, nan, nan, nan, nan}
 		timestampsExpected := []int64{0, 1, 2, 3, 4}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -267,14 +341,14 @@ func TestRollupNoWindowNoPoints(t *testing.T) {
 		rc := rollupConfig{
 			Func:   rollupDelta,
 			Start:  120,
-			End:    144,
+			End:    148,
 			Step:   4,
 			Window: 0,
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{2, 2, 0, 0, 0, nan, nan}
-		timestampsExpected := []int64{120, 124, 128, 132, 136, 140, 144}
+		valuesExpected := []float64{2, 0, 0, 0, 0, 0, 0, nan}
+		timestampsExpected := []int64{120, 124, 128, 132, 136, 140, 144, 148}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
 }
@@ -290,7 +364,7 @@ func TestRollupWindowNoPoints(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{nan, nan, nan, nan, 123}
+		valuesExpected := []float64{nan, nan, nan, nan, nan}
 		timestampsExpected := []int64{0, 1, 2, 3, 4}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -315,14 +389,14 @@ func TestRollupNoWindowPartialPoints(t *testing.T) {
 		rc := rollupConfig{
 			Func:   rollupFirst,
 			Start:  0,
-			End:    20,
+			End:    25,
 			Step:   5,
 			Window: 0,
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{123, 123, 123, 123, 123}
-		timestampsExpected := []int64{0, 5, 10, 15, 20}
+		valuesExpected := []float64{nan, 123, 123, 123, 34, 34}
+		timestampsExpected := []int64{0, 5, 10, 15, 20, 25}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
 	t.Run("afterEnd", func(t *testing.T) {
@@ -335,7 +409,7 @@ func TestRollupNoWindowPartialPoints(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{44, 34, 34, nan}
+		valuesExpected := []float64{12, 44, 34, 34}
 		timestampsExpected := []int64{100, 120, 140, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -349,7 +423,7 @@ func TestRollupNoWindowPartialPoints(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{nan, 123, 54, 44, nan}
+		valuesExpected := []float64{nan, nan, 123, 54, 44}
 		timestampsExpected := []int64{-50, 0, 50, 100, 150}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -366,7 +440,7 @@ func TestRollupWindowPartialPoints(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{123, 123, 34, 34, 44}
+		valuesExpected := []float64{nan, 123, 123, 34, 34}
 		timestampsExpected := []int64{0, 5, 10, 15, 20}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -380,7 +454,7 @@ func TestRollupWindowPartialPoints(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{34, 34, nan, nan}
+		valuesExpected := []float64{44, 34, 34, nan}
 		timestampsExpected := []int64{100, 120, 140, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -394,7 +468,7 @@ func TestRollupWindowPartialPoints(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{54, 44, nan, nan}
+		valuesExpected := []float64{nan, 54, 44, 34}
 		timestampsExpected := []int64{0, 50, 100, 150}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -411,7 +485,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{123, 21, 12, 34, nan}
+		valuesExpected := []float64{nan, 123, 21, 12, 34}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -425,7 +499,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{4, 4, 3, 1, nan}
+		valuesExpected := []float64{nan, 4, 4, 3, 1}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -439,7 +513,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{21, 12, 32, 34, nan}
+		valuesExpected := []float64{nan, 21, 12, 32, 34}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -453,7 +527,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{123, 99, 44, 34, nan}
+		valuesExpected := []float64{nan, 123, 99, 44, 34}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -467,7 +541,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{222, 199, 110, 34, nan}
+		valuesExpected := []float64{nan, 222, 199, 110, 34}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -481,7 +555,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{-102, -9, 22, 0, nan}
+		valuesExpected := []float64{nan, -102, -9, 22, 0}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -495,7 +569,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{33, -87, 0, nan}
+		valuesExpected := []float64{0, 33, -87, 0}
 		timestampsExpected := []int64{10, 50, 90, 130}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -509,10 +583,24 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{3, 4, 3, 0, nan}
+		valuesExpected := []float64{nan, 4, 4, 3, 0}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
+	t.Run("changes_small_window", func(t *testing.T) {
+		rc := rollupConfig{
+			Func:   rollupChanges,
+			Start:  0,
+			End:    45,
+			Step:   9,
+			Window: 9,
+		}
+		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
+		values := rc.Do(nil, testValues, testTimestamps)
+		valuesExpected := []float64{nan, 1, 1, 1, 1, 0}
+		timestampsExpected := []int64{0, 9, 18, 27, 36, 45}
+		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
+	})
 	t.Run("resets", func(t *testing.T) {
 		rc := rollupConfig{
 			Func:   rollupResets,
@@ -523,7 +611,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{2, 2, 1, 0, nan}
+		valuesExpected := []float64{nan, 2, 2, 1, 0}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -537,13 +625,13 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{55.5, 49.75, 36.666666666666664, 34, nan}
+		valuesExpected := []float64{nan, 55.5, 49.75, 36.666666666666664, 34}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
 	t.Run("deriv", func(t *testing.T) {
 		rc := rollupConfig{
-			Func:   rollupDeriv,
+			Func:   rollupDerivSlow,
 			Start:  0,
 			End:    160,
 			Step:   40,
@@ -551,7 +639,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{-3290.3225806451615, -204.54545454545456, 550, 0, nan}
+		valuesExpected := []float64{0, -2879.310344827587, 558.0608793686592, 422.84569138276544, 0}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -565,7 +653,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{-1916.6666666666665, -43500, 400, 0, nan}
+		valuesExpected := []float64{nan, -1916.6666666666665, -43500, 400, 0}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -579,7 +667,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{39.81519810323691, 32.080952292598795, 5.2493385826745405, 0, nan}
+		valuesExpected := []float64{nan, 39.81519810323691, 32.080952292598795, 5.2493385826745405, 5.830951894845301}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -593,7 +681,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{4.6035, 4.3934999999999995, 2.166, 0.34, nan}
+		valuesExpected := []float64{nan, 4.6035, 4.3934999999999995, 2.166, 0.34}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -607,7 +695,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{4, 4, 3, 1, nan}
+		valuesExpected := []float64{nan, 4, 4, 3, 1}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})

app/vmselect/promql/timeseries.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"sort"
 	"strconv"
+	"sync"
 	"unsafe"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
@@ -38,11 +39,13 @@ func (ts *timeseries) String() string {
 	return fmt.Sprintf("MetricName=%s, Values=%g, Timestamps=%d", &ts.MetricName, ts.Values, ts.Timestamps)
 }
 
-func (ts *timeseries) CopyFrom(src *timeseries) {
+func (ts *timeseries) CopyFromShallowTimestamps(src *timeseries) {
 	ts.Reset()
 	ts.MetricName.CopyFrom(&src.MetricName)
 	ts.Values = append(ts.Values[:0], src.Values...)
-	ts.Timestamps = append(ts.Timestamps[:0], src.Timestamps...)
+	ts.Timestamps = src.Timestamps
+
+	ts.denyReuse = true
 }
 
 func (ts *timeseries) CopyFromMetricNames(src *timeseries) {
@@ -59,6 +62,20 @@ func (ts *timeseries) CopyShallow(src *timeseries) {
 	ts.denyReuse = true
 }
 
+func getTimeseries() *timeseries {
+	if v := timeseriesPool.Get(); v != nil {
+		return v.(*timeseries)
+	}
+	return &timeseries{}
+}
+
+func putTimeseries(ts *timeseries) {
+	ts.Reset()
+	timeseriesPool.Put(ts)
+}
+
+var timeseriesPool sync.Pool
+
 func marshalTimeseriesFast(tss []*timeseries, maxSize int, step int64) []byte {
 	if len(tss) == 0 {
 		logger.Panicf("BUG: tss cannot be empty")

app/vmselect/promql/transform.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"math"
 	"math/rand"
+	"regexp"
 	"sort"
 	"strconv"
 	"strings"
@@ -61,6 +62,7 @@ var transformFuncs = map[string]transformFunc{
 	"label_keep":         transformLabelKeep,
 	"label_copy":         transformLabelCopy,
 	"label_move":         transformLabelMove,
+	"label_transform":    transformLabelTransform,
 	"union":              transformUnion,
 	"":                   transformUnion, // empty func is a synonim to union
 	"keep_last_value":    transformKeepLastValue,
@@ -123,7 +125,8 @@ func newTransformFuncOneArg(tf func(v float64) float64) transformFunc {
 }
 
 func doTransformValues(arg []*timeseries, tf func(values []float64), fe *funcExpr) ([]*timeseries, error) {
-	keepMetricGroup := transformFuncsKeepMetricGroup[fe.Name]
+	name := strings.ToLower(fe.Name)
+	keepMetricGroup := transformFuncsKeepMetricGroup[name]
 	for _, ts := range arg {
 		if !keepMetricGroup {
 			ts.MetricName.ResetMetricGroup()
@@ -294,14 +297,12 @@ func transformHistogramQuantile(tfa *transformFuncArg) ([]*timeseries, error) {
 		if err != nil {
 			continue
 		}
-		var dst timeseries
-		dst.CopyFrom(ts)
-		dst.MetricName.ResetMetricGroup()
-		dst.MetricName.RemoveTag("le")
-		bb.B = marshalMetricTagsSorted(bb.B[:0], &dst.MetricName)
+		ts.MetricName.ResetMetricGroup()
+		ts.MetricName.RemoveTag("le")
+		bb.B = marshalMetricTagsSorted(bb.B[:0], &ts.MetricName)
 		m[string(bb.B)] = append(m[string(bb.B)], x{
 			le: le,
-			ts: &dst,
+			ts: ts,
 		})
 	}
 	bbPool.Put(bb)
@@ -394,13 +395,6 @@ func runningAvg(a, b float64, idx int) float64 {
 	return a + (b-a)/float64(idx+1)
 }
 
-func keepLastValue(a, b float64, idx int) float64 {
-	if math.IsNaN(b) {
-		return a
-	}
-	return b
-}
-
 func skipLeadingNaNs(values []float64) []float64 {
 	i := 0
 	for i < len(values) && math.IsNaN(values[i]) {
@@ -641,9 +635,7 @@ func transformUnion(tfa *transformFuncArg) ([]*timeseries, error) {
 				continue
 			}
 			m[string(bb.B)] = true
-			var dst timeseries
-			dst.CopyFrom(ts)
-			rvs = append(rvs, &dst)
+			rvs = append(rvs, ts)
 		}
 	}
 	bbPool.Put(bb)
@@ -816,6 +808,31 @@ func transformLabelJoin(tfa *transformFuncArg) ([]*timeseries, error) {
 	return rvs, nil
 }
 
+func transformLabelTransform(tfa *transformFuncArg) ([]*timeseries, error) {
+	args := tfa.args
+	if err := expectTransformArgsNum(args, 4); err != nil {
+		return nil, err
+	}
+	label, err := getString(args[1], 1)
+	if err != nil {
+		return nil, err
+	}
+	regex, err := getString(args[2], 2)
+	if err != nil {
+		return nil, err
+	}
+	replacement, err := getString(args[3], 3)
+	if err != nil {
+		return nil, err
+	}
+
+	r, err := compileRegexp(regex)
+	if err != nil {
+		return nil, fmt.Errorf(`cannot compile regex %q: %s`, regex, err)
+	}
+	return labelReplace(args[0], label, r, label, replacement)
+}
+
 func transformLabelReplace(tfa *transformFuncArg) ([]*timeseries, error) {
 	args := tfa.args
 	if err := expectTransformArgsNum(args, 5); err != nil {
@@ -842,11 +859,12 @@ func transformLabelReplace(tfa *transformFuncArg) ([]*timeseries, error) {
 	if err != nil {
 		return nil, fmt.Errorf(`cannot compile regex %q: %s`, regex, err)
 	}
+	return labelReplace(args[0], srcLabel, r, dstLabel, replacement)
+}
 
+func labelReplace(tss []*timeseries, srcLabel string, r *regexp.Regexp, dstLabel, replacement string) ([]*timeseries, error) {
 	replacementBytes := []byte(replacement)
-
-	rvs := args[0]
-	for _, ts := range rvs {
+	for _, ts := range tss {
 		mn := &ts.MetricName
 		dstValue := getDstValue(mn, dstLabel)
 		srcValue := mn.GetTagValue(srcLabel)
@@ -856,7 +874,7 @@ func transformLabelReplace(tfa *transformFuncArg) ([]*timeseries, error) {
 			mn.RemoveTag(dstLabel)
 		}
 	}
-	return rvs, nil
+	return tss, nil
 }
 
 func transformLn(v float64) float64 {

app/vmstorage/main.go

@@ -28,11 +28,20 @@ var (
 
 // Init initializes vmstorage.
 func Init() {
+	InitWithoutMetrics()
+	registerStorageMetrics()
+}
+
+// InitWithoutMetrics must be called instead of Init inside tests.
+//
+// This allows multiple Init / Stop cycles.
+func InitWithoutMetrics() {
 	if err := encoding.CheckPrecisionBits(uint8(*precisionBits)); err != nil {
 		logger.Fatalf("invalid `-precisionBits`: %s", err)
 	}
 	logger.Infof("opening storage at %q with retention period %d months", *DataPath, *retentionPeriod)
 	startTime := time.Now()
+	WG = syncwg.WaitGroup{}
 	strg, err := storage.OpenStorage(*DataPath, *retentionPeriod)
 	if err != nil {
 		logger.Fatalf("cannot open a storage at %s with retention period %d months: %s", *DataPath, *retentionPeriod, err)
@@ -45,10 +54,9 @@ func Init() {
 	partsCount := tm.SmallPartsCount + tm.BigPartsCount
 	blocksCount := tm.SmallBlocksCount + tm.BigBlocksCount
 	rowsCount := tm.SmallRowsCount + tm.BigRowsCount
-	logger.Infof("successfully opened storage %q in %s; partsCount: %d; blocksCount: %d; rowsCount: %d",
-		*DataPath, time.Since(startTime), partsCount, blocksCount, rowsCount)
-
-	registerStorageMetrics(Storage)
+	sizeBytes := tm.SmallSizeBytes + tm.BigSizeBytes
+	logger.Infof("successfully opened storage %q in %s; partsCount: %d; blocksCount: %d; rowsCount: %d; sizeBytes: %d",
+		*DataPath, time.Since(startTime), partsCount, blocksCount, rowsCount, sizeBytes)
 }
 
 // Storage is a storage.
@@ -96,6 +104,14 @@ func SearchTagValues(tagKey []byte, maxTagValues int) ([]string, error) {
 	return values, err
 }
 
+// SearchTagEntries searches for tag entries.
+func SearchTagEntries(maxTagKeys, maxTagValues int) ([]storage.TagEntry, error) {
+	WG.Add(1)
+	tagEntries, err := Storage.SearchTagEntries(maxTagKeys, maxTagValues)
+	WG.Done()
+	return tagEntries, err
+}
+
 // GetSeriesCount returns the number of time series in the storage.
 func GetSeriesCount() (uint64, error) {
 	WG.Add(1)
@@ -203,7 +219,7 @@ func RequestHandler(w http.ResponseWriter, r *http.Request) bool {
 	}
 }
 
-func registerStorageMetrics(strg *storage.Storage) {
+func registerStorageMetrics() {
 	mCache := &storage.Metrics{}
 	var mCacheLock sync.Mutex
 	var lastUpdateTime time.Time
@@ -215,7 +231,7 @@ func registerStorageMetrics(strg *storage.Storage) {
 			return mCache
 		}
 		var mc storage.Metrics
-		strg.UpdateMetrics(&mc)
+		Storage.UpdateMetrics(&mc)
 		mCache = &mc
 		lastUpdateTime = time.Now()
 		return mCache
@@ -285,6 +301,18 @@ func registerStorageMetrics(strg *storage.Storage) {
 	metrics.NewGauge(`vm_missing_tsids_for_metric_id_total`, func() float64 {
 		return float64(idbm().MissingTSIDsForMetricID)
 	})
+	metrics.NewGauge(`vm_recent_hour_metric_ids_search_calls_total`, func() float64 {
+		return float64(idbm().RecentHourMetricIDsSearchCalls)
+	})
+	metrics.NewGauge(`vm_recent_hour_metric_ids_search_hits_total`, func() float64 {
+		return float64(idbm().RecentHourMetricIDsSearchHits)
+	})
+	metrics.NewGauge(`vm_date_metric_ids_search_calls_total`, func() float64 {
+		return float64(idbm().DateMetricIDsSearchCalls)
+	})
+	metrics.NewGauge(`vm_date_metric_ids_search_hits_total`, func() float64 {
+		return float64(idbm().DateMetricIDsSearchHits)
+	})
 
 	metrics.NewGauge(`vm_assisted_merges_total{type="storage/small"}`, func() float64 {
 		return float64(tm().SmallAssistedMerges)
@@ -320,6 +348,16 @@ func registerStorageMetrics(strg *storage.Storage) {
 		return float64(idbm().BlocksCount)
 	})
 
+	metrics.NewGauge(`vm_data_size_bytes{type="storage/big"}`, func() float64 {
+		return float64(tm().BigSizeBytes)
+	})
+	metrics.NewGauge(`vm_data_size_bytes{type="storage/small"}`, func() float64 {
+		return float64(tm().SmallSizeBytes)
+	})
+	metrics.NewGauge(`vm_data_size_bytes{type="indexdb"}`, func() float64 {
+		return float64(idbm().SizeBytes)
+	})
+
 	metrics.NewGauge(`vm_rows{type="storage/big"}`, func() float64 {
 		return float64(tm().BigRowsCount)
 	})
@@ -342,6 +380,9 @@ func registerStorageMetrics(strg *storage.Storage) {
 	metrics.NewGauge(`vm_cache_entries{type="storage/date_metricID"}`, func() float64 {
 		return float64(m().DateMetricIDCacheSize)
 	})
+	metrics.NewGauge(`vm_cache_entries{type="storage/hour_metric_ids"}`, func() float64 {
+		return float64(m().HourMetricIDCacheSize)
+	})
 	metrics.NewGauge(`vm_cache_entries{type="storage/bigIndexBlocks"}`, func() float64 {
 		return float64(tm().BigIndexBlocksCacheSize)
 	})
@@ -357,24 +398,30 @@ func registerStorageMetrics(strg *storage.Storage) {
 	metrics.NewGauge(`vm_cache_entries{type="indexdb/tagFilters"}`, func() float64 {
 		return float64(idbm().TagCacheSize)
 	})
+	metrics.NewGauge(`vm_cache_entries{type="indexdb/uselessTagFilters"}`, func() float64 {
+		return float64(idbm().UselessTagFiltersCacheSize)
+	})
 	metrics.NewGauge(`vm_cache_entries{type="storage/regexps"}`, func() float64 {
 		return float64(storage.RegexpCacheSize())
 	})
 
 	metrics.NewGauge(`vm_cache_size_bytes{type="storage/tsid"}`, func() float64 {
-		return float64(m().TSIDCacheBytesSize)
+		return float64(m().TSIDCacheSizeBytes)
 	})
 	metrics.NewGauge(`vm_cache_size_bytes{type="storage/metricIDs"}`, func() float64 {
-		return float64(m().MetricIDCacheBytesSize)
+		return float64(m().MetricIDCacheSizeBytes)
 	})
 	metrics.NewGauge(`vm_cache_size_bytes{type="storage/metricName"}`, func() float64 {
-		return float64(m().MetricNameCacheBytesSize)
+		return float64(m().MetricNameCacheSizeBytes)
 	})
 	metrics.NewGauge(`vm_cache_size_bytes{type="storage/date_metricID"}`, func() float64 {
-		return float64(m().DateMetricIDCacheBytesSize)
+		return float64(m().DateMetricIDCacheSizeBytes)
 	})
 	metrics.NewGauge(`vm_cache_size_bytes{type="indexdb/tagFilters"}`, func() float64 {
-		return float64(idbm().TagCacheBytesSize)
+		return float64(idbm().TagCacheSizeBytes)
+	})
+	metrics.NewGauge(`vm_cache_size_bytes{type="indexdb/uselessTagFilters"}`, func() float64 {
+		return float64(idbm().UselessTagFiltersCacheSizeBytes)
 	})
 
 	metrics.NewGauge(`vm_cache_requests_total{type="storage/tsid"}`, func() float64 {
@@ -404,6 +451,9 @@ func registerStorageMetrics(strg *storage.Storage) {
 	metrics.NewGauge(`vm_cache_requests_total{type="indexdb/tagFilters"}`, func() float64 {
 		return float64(idbm().TagCacheRequests)
 	})
+	metrics.NewGauge(`vm_cache_requests_total{type="indexdb/uselessTagFilters"}`, func() float64 {
+		return float64(idbm().UselessTagFiltersCacheRequests)
+	})
 	metrics.NewGauge(`vm_cache_requests_total{type="storage/regexps"}`, func() float64 {
 		return float64(storage.RegexpCacheRequests())
 	})
@@ -435,6 +485,9 @@ func registerStorageMetrics(strg *storage.Storage) {
 	metrics.NewGauge(`vm_cache_misses_total{type="indexdb/tagFilters"}`, func() float64 {
 		return float64(idbm().TagCacheMisses)
 	})
+	metrics.NewGauge(`vm_cache_misses_total{type="indexdb/uselessTagFilters"}`, func() float64 {
+		return float64(idbm().UselessTagFiltersCacheMisses)
+	})
 	metrics.NewGauge(`vm_cache_misses_total{type="storage/regexps"}`, func() float64 {
 		return float64(storage.RegexpCacheMisses())
 	})

deployment/docker/Makefile

@@ -1,5 +1,5 @@
-DOCKER_NAMESPACE := valyala
-BUILDER_IMAGE := local/builder:go1.12.5
+DOCKER_NAMESPACE := victoriametrics
+BUILDER_IMAGE := local/builder:go1.12.6
 CERTS_IMAGE := local/certs:1.0.2
 
 package-certs:
@@ -18,6 +18,7 @@ app-via-docker: package-certs package-builder
 		-w /VictoriaMetrics \
 		--mount type=bind,src="$(shell pwd)/gocache-for-docker",dst=/gocache \
 		--env GOCACHE=/gocache \
+		--env GO111MODULE=on \
 		$(BUILDER_IMAGE) \
 		go build $(RACE) -mod=vendor -ldflags "-s -w -extldflags '-static' $(GO_BUILDINFO)" -tags 'netgo osusergo' -o bin/$(APP_NAME)-prod $(PKG_PREFIX)/app/$(APP_NAME)
 

deployment/docker/README.md

@@ -0,0 +1,33 @@
+### Folder contains basic images and tools for building and running Victoria Metrics in docker
+
+#### Docker compose
+
+To spin-up setup of VictoriaMetrics, Prometheus and Grafana run following command:
+
+`docker-compose up`
+
+##### VictoriaMetrics
+
+VictoriaMetrics opens following ports:
+* `--graphiteListenAddr=:2003`
+* `--opentsdbListenAddr=:4242`
+* `--httpListenAddr=:8428`
+
+##### Prometheus
+
+To access service open following [link](http://localhost:9090).
+
+Prometheus is already configured to use VictoriaMetrics as remote storage.
+
+##### Grafana
+
+To access service open following [link](http://localhost:3000).
+
+Default creds:
+* login - `admin`
+* password - `admin`
+
+Grafana is provisioned by default with following entities:
+* VictoriaMetrics datasource
+* Prometheus datasource
+* VictoriaMetrics overview dashboard

deployment/docker/builder/Dockerfile

@@ -1 +1,2 @@
-FROM golang:1.12.5
+FROM golang:1.12.6
+STOPSIGNAL SIGINT

deployment/docker/docker-compose.yml

@@ -0,0 +1,61 @@
+version: '3.5'
+services:
+  prometheus:
+    container_name: prometheus
+    image: prom/prometheus:v2.10.0
+    depends_on:
+      - "victoriametrics"
+    ports:
+      - 9090:9090
+    volumes:
+      - promdata:/prometheus
+      - ./prometheus.yml:/etc/prometheus/prometheus.yml
+    command:
+      - '--config.file=/etc/prometheus/prometheus.yml'
+      - '--storage.tsdb.path=/prometheus'
+    networks:
+      - vm_net
+    restart: always
+  victoriametrics:
+    container_name: victoriametrics
+    image: victoriametrics/victoria-metrics
+    ports:
+      - 8428:8428
+      - 2003:2003
+      - 4242:4242
+    volumes:
+      - vmdata:/storage
+    command:
+      - '--storageDataPath=/storage'
+      - '--graphiteListenAddr=:2003'
+      - '--opentsdbListenAddr=:4242'
+      - '--httpListenAddr=:8428'
+    networks:
+      - vm_net
+    restart: always
+  grafana:
+    container_name: grafana
+    image: grafana/grafana:6.2.1
+    entrypoint: >
+      /bin/sh -c "
+      cd /var/lib/grafana &&
+      mkdir -p dashboards &&
+      sed 's/$${DS_PROMETHEUS}/Prometheus/g' vm.json > dashboards/vm.json &&
+      /run.sh"
+    depends_on:
+      - "victoriametrics"
+    ports:
+      - 3000:3000
+    volumes:
+      - grafanadata:/var/lib/grafana
+      - ./provisioning/:/etc/grafana/provisioning/
+      - ./../../dashboards/victoriametrics.json:/var/lib/grafana/vm.json
+    networks:
+      - vm_net
+    restart: always
+volumes:
+  promdata: {}
+  vmdata: {}
+  grafanadata: {}
+networks:
+  vm_net:

deployment/docker/prometheus.yml

@@ -0,0 +1,16 @@
+global:
+  scrape_interval:     10s
+  evaluation_interval: 10s
+
+remote_write:
+  - url: "http://victoriametrics:8428/api/v1/write"
+    queue_config:
+      max_samples_per_send: 10000
+
+scrape_configs:
+  - job_name: 'prometheus'
+    static_configs:
+      - targets: ['prometheus:9090']
+  - job_name: 'victoriametrics'
+    static_configs:
+      - targets: ['victoriametrics:8428']

deployment/docker/provisioning/dashboards/dashboard.yml

@@ -0,0 +1,9 @@
+apiVersion: 1
+
+providers:
+- name: Prometheus
+  orgId: 1
+  folder: ''
+  type: file
+  options:
+    path: /var/lib/grafana/dashboards

deployment/docker/provisioning/datasources/datasource.yml

@@ -0,0 +1,14 @@
+apiVersion: 1
+
+datasources:
+    - name: Prometheus
+      type: prometheus
+      access: proxy
+      url: http://prometheus:9090
+      isDefault: false
+
+    - name: VictoriaMetrics
+      type: prometheus
+      access: proxy
+      url: http://victoriametrics:8428
+      isDefault: true

go.mod

@@ -1,16 +1,16 @@
 module github.com/VictoriaMetrics/VictoriaMetrics
 
 require (
-	github.com/VictoriaMetrics/fastcache v1.5.0
-	github.com/VictoriaMetrics/metrics v1.4.0
+	github.com/VictoriaMetrics/fastcache v1.5.1
+	github.com/VictoriaMetrics/metrics v1.6.2
 	github.com/cespare/xxhash/v2 v2.0.1-0.20190104013014-3767db7a7e18
 	github.com/golang/snappy v0.0.1
 	github.com/spaolacci/murmur3 v1.1.0 // indirect
 	github.com/valyala/fastjson v1.4.1
-	github.com/valyala/gozstd v1.5.0
+	github.com/valyala/gozstd v1.5.1
 	github.com/valyala/histogram v1.0.1
 	github.com/valyala/quicktemplate v1.1.1
-	golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82
+	golang.org/x/sys v0.0.0-20190616124812-15dcb6c0061f
 )
 
 go 1.12

go.sum

@@ -1,10 +1,10 @@
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/OneOfOne/xxhash v1.2.5 h1:zl/OfRA6nftbBK9qTohYBJ5xvw6C/oNKizR7cZGl3cI=
 github.com/OneOfOne/xxhash v1.2.5/go.mod h1:eZbhyaAYD41SGSSsnmcpxVoRiQ/MPUTjUdIIOT9Um7Q=
-github.com/VictoriaMetrics/fastcache v1.5.0 h1:z8t2QV/CDXWVJ9vy9yRtGGDoOvk9W2aXQBijbLk0KCc=
-github.com/VictoriaMetrics/fastcache v1.5.0/go.mod h1:+jv9Ckb+za/P1ZRg/sulP5Ni1v49daAVERr0H3CuscE=
-github.com/VictoriaMetrics/metrics v1.4.0 h1:3+XdciC4E8sywx+0PStXhtIdWxXP2bdJ06Whw0mViQE=
-github.com/VictoriaMetrics/metrics v1.4.0/go.mod h1:QZAL5yLaXvhSPeib0ahluGo9VK0HXDZHovKaKlpuWvs=
+github.com/VictoriaMetrics/fastcache v1.5.1 h1:qHgHjyoNFV7jgucU8QZUuU4gcdhfs8QW1kw68OD2Lag=
+github.com/VictoriaMetrics/fastcache v1.5.1/go.mod h1:+jv9Ckb+za/P1ZRg/sulP5Ni1v49daAVERr0H3CuscE=
+github.com/VictoriaMetrics/metrics v1.6.2 h1:VMe8c8ZBPgNVZkPoT06LsoU2nb+8e7iPaOWbVRNhxjo=
+github.com/VictoriaMetrics/metrics v1.6.2/go.mod h1:LU2j9qq7xqZYXz8tF3/RQnB2z2MbZms5TDiIg9/NHiQ=
 github.com/allegro/bigcache v1.2.1-0.20190218064605-e24eb225f156 h1:eMwmnE/GDgah4HI848JfFxHt+iPb26b4zyfspmqY0/8=
 github.com/allegro/bigcache v1.2.1-0.20190218064605-e24eb225f156/go.mod h1:Cb/ax3seSYIx7SuZdm2G2xzfwmv3TPSk2ucNfQESPXM=
 github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
@@ -36,13 +36,13 @@ github.com/valyala/fastjson v1.4.1 h1:hrltpHpIpkaxll8QltMU8c3QZ5+qIiCL8yKqPFJI/y
 github.com/valyala/fastjson v1.4.1/go.mod h1:nV6MsjxL2IMJQUoHDIrjEI7oLyeqK6aBD7EFWPsvP8o=
 github.com/valyala/fastrand v1.0.0 h1:LUKT9aKer2dVQNUi3waewTbKV+7H17kvWFNKs2ObdkI=
 github.com/valyala/fastrand v1.0.0/go.mod h1:HWqCzkrkg6QXT8V2EXWvXCoow7vLwOFN002oeRzjapQ=
-github.com/valyala/gozstd v1.5.0 h1:OI7Z2e+GkvmmdRFiJeyuByhT/WMTLuRLa43Z2Tjzenw=
-github.com/valyala/gozstd v1.5.0/go.mod h1:oYOS+oJovjw9ewtrwEYb9+ybolEXd6pHyLMuAWN5zts=
+github.com/valyala/gozstd v1.5.1 h1:ZLepItgu2g+B2CfVQy6KCV/as8lnJ7ef1KU6DPxQSS0=
+github.com/valyala/gozstd v1.5.1/go.mod h1:oYOS+oJovjw9ewtrwEYb9+ybolEXd6pHyLMuAWN5zts=
 github.com/valyala/histogram v1.0.1 h1:FzA7n2Tz/wKRMejgu3PV1vw3htAklTjjuoI6z3d4KDg=
 github.com/valyala/histogram v1.0.1/go.mod h1:lQy0xA4wUz2+IUnf97SivorsJIp8FxsnRd6x25q7Mto=
 github.com/valyala/quicktemplate v1.1.1 h1:C58y/wN0FMTi2PR0n3onltemfFabany53j7M6SDDB8k=
 github.com/valyala/quicktemplate v1.1.1/go.mod h1:EH+4AkTd43SvgIbQHYu59/cJyxDoOVRUAfrukLPuGJ4=
 github.com/valyala/tcplisten v0.0.0-20161114210144-ceec8f93295a/go.mod h1:v3UYOV9WzVtRmSR+PDvWpU/qWl4Wa5LApYYX4ZtKbio=
 golang.org/x/net v0.0.0-20180911220305-26e67e76b6c3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82 h1:vsphBvatvfbhlb4PO1BYSr9dzugGxJ/SQHoNufZJq1w=
-golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190616124812-15dcb6c0061f h1:25KHgbfyiSm6vwQLbM3zZIe1v9p/3ea4Rz+nnM5K/i4=
+golang.org/x/sys v0.0.0-20190616124812-15dcb6c0061f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

lib/bytesutil/bytebuffer.go

@@ -13,6 +13,7 @@ var (
 	// Verify ByteBuffer implements the given interfaces.
 	_ io.Writer       = &ByteBuffer{}
 	_ fs.ReadAtCloser = &ByteBuffer{}
+	_ io.ReaderFrom   = &ByteBuffer{}
 
 	// Verify reader implement filestream.ReadCloser interface.
 	_ filestream.ReadCloser = &reader{}
@@ -44,7 +45,31 @@ func (bb *ByteBuffer) ReadAt(p []byte, offset int64) {
 		logger.Panicf("BUG: too big offset=%d; cannot exceed len(bb.B)=%d", offset, len(bb.B))
 	}
 	if n := copy(p, bb.B[offset:]); n < len(p) {
-		logger.Panicf("BUG: EOF occured after reading %d bytes out of %d bytes at offset %d", n, len(p), offset)
+		logger.Panicf("BUG: EOF occurred after reading %d bytes out of %d bytes at offset %d", n, len(p), offset)
+	}
+}
+
+// ReadFrom reads all the data from r to bb until EOF.
+func (bb *ByteBuffer) ReadFrom(r io.Reader) (int64, error) {
+	b := bb.B
+	bLen := len(b)
+	b = Resize(b, 4*1024)
+	b = b[:cap(b)]
+	offset := bLen
+	for {
+		if free := len(b) - offset; free < offset {
+			n := len(b)
+			b = append(b, make([]byte, n)...)
+		}
+		n, err := r.Read(b[offset:])
+		offset += n
+		if err != nil {
+			bb.B = b[:offset]
+			if err == io.EOF {
+				err = nil
+			}
+			return int64(offset - bLen), err
+		}
 	}
 }
 

lib/bytesutil/bytebuffer_test.go

@@ -1,6 +1,7 @@
 package bytesutil
 
 import (
+	"bytes"
 	"fmt"
 	"io"
 	"testing"
@@ -66,6 +67,92 @@ func TestByteBuffer(t *testing.T) {
 	}
 }
 
+func TestByteBufferReadFrom(t *testing.T) {
+	var bbPool ByteBufferPool
+
+	t.Run("zero_bytes", func(t *testing.T) {
+		t.Parallel()
+		bb := bbPool.Get()
+		defer bbPool.Put(bb)
+		src := bytes.NewBufferString("")
+		n, err := bb.ReadFrom(src)
+		if err != nil {
+			t.Fatalf("error when reading empty string: %s", err)
+		}
+		if n != 0 {
+			t.Fatalf("unexpected number of bytes read; got %d; want %d", n, 0)
+		}
+		if len(bb.B) != 0 {
+			t.Fatalf("unexpejcted len(bb.B); got %d; want %d", len(bb.B), 0)
+		}
+	})
+
+	t.Run("non_zero_bytes", func(t *testing.T) {
+		t.Parallel()
+		bb := bbPool.Get()
+		defer bbPool.Put(bb)
+		s := "foobarbaz"
+		src := bytes.NewBufferString(s)
+		n, err := bb.ReadFrom(src)
+		if err != nil {
+			t.Fatalf("error when reading non-empty string: %s", err)
+		}
+		if n != int64(len(s)) {
+			t.Fatalf("unexpected number of bytes read; got %d; want %d", n, len(s))
+		}
+		if string(bb.B) != s {
+			t.Fatalf("unexpected value read; got %q; want %q", bb.B, s)
+		}
+	})
+
+	t.Run("big_number_of_bytes", func(t *testing.T) {
+		t.Parallel()
+		bb := bbPool.Get()
+		defer bbPool.Put(bb)
+		b := make([]byte, 1024*1024+234)
+		for i := range b {
+			b[i] = byte(i)
+		}
+		src := bytes.NewBuffer(b)
+		n, err := bb.ReadFrom(src)
+		if err != nil {
+			t.Fatalf("cannot read big value: %s", err)
+		}
+		if n != int64(len(b)) {
+			t.Fatalf("unexpected number of bytes read; got %d; want %d", n, len(b))
+		}
+		if string(bb.B) != string(b) {
+			t.Fatalf("unexpected value read; got %q; want %q", bb.B, b)
+		}
+	})
+
+	t.Run("non_empty_bb", func(t *testing.T) {
+		t.Parallel()
+		bb := bbPool.Get()
+		defer bbPool.Put(bb)
+		prefix := []byte("prefix")
+		bb.B = append(bb.B[:0], prefix...)
+		s := "aosdfdsafdjsf"
+		src := bytes.NewBufferString(s)
+		n, err := bb.ReadFrom(src)
+		if err != nil {
+			t.Fatalf("cannot read to non-empty bb: %s", err)
+		}
+		if n != int64(len(s)) {
+			t.Fatalf("unexpected number of bytes read; got %d; want %d", n, len(s))
+		}
+		if len(bb.B) != len(prefix)+len(s) {
+			t.Fatalf("unexpected bb.B len; got %d; want %d", len(bb.B), len(prefix)+len(s))
+		}
+		if string(bb.B[:len(prefix)]) != string(prefix) {
+			t.Fatalf("unexpected prefix; got %q; want %q", bb.B[:len(prefix)], prefix)
+		}
+		if string(bb.B[len(prefix):]) != s {
+			t.Fatalf("unexpected data read; got %q; want %q", bb.B[len(prefix):], s)
+		}
+	})
+}
+
 func TestByteBufferRead(t *testing.T) {
 	var bb ByteBuffer
 

lib/decimal/decimal.go

@@ -186,6 +186,7 @@ func maxUpExponent(v int64) int16 {
 		v = -v
 	}
 	if v < 0 {
+		// Handle corner case for v=-1<<63
 		return 0
 	}
 

lib/encoding/compress.go

@@ -1,27 +1,34 @@
 package encoding
 
 import (
+	"github.com/VictoriaMetrics/metrics"
 	"github.com/valyala/gozstd"
 )
 
-// CompressZSTD compresses src, appends the result to dst and returns
-// the appended dst.
-//
-// src must be non-empty.
-func CompressZSTD(dst, src []byte) []byte {
-	return gozstd.CompressLevel(dst, src, 5)
-}
-
 // CompressZSTDLevel appends compressed src to dst and returns
 // the appended dst.
 //
 // The given compressLevel is used for the compression.
 func CompressZSTDLevel(dst, src []byte, compressLevel int) []byte {
-	return gozstd.CompressLevel(dst, src, compressLevel)
+	compressCalls.Inc()
+	originalBytes.Add(len(src))
+	dstLen := len(dst)
+	dst = gozstd.CompressLevel(dst, src, compressLevel)
+	compressedBytes.Add(len(dst) - dstLen)
+	return dst
 }
 
 // DecompressZSTD decompresses src, appends the result to dst and returns
 // the appended dst.
 func DecompressZSTD(dst, src []byte) ([]byte, error) {
+	decompressCalls.Inc()
 	return gozstd.Decompress(dst, src)
 }
+
+var (
+	compressCalls   = metrics.NewCounter(`vm_zstd_block_compress_calls_total`)
+	decompressCalls = metrics.NewCounter(`vm_zstd_block_decompress_calls_total`)
+
+	originalBytes   = metrics.NewCounter(`vm_zstd_block_original_bytes_total`)
+	compressedBytes = metrics.NewCounter(`vm_zstd_block_compressed_bytes_total`)
+)

lib/encoding/compress_test.go

@@ -17,7 +17,7 @@ func TestCompressDecompressZSTD(t *testing.T) {
 }
 
 func testCompressDecompressZSTD(t *testing.T, b []byte) {
-	bc := CompressZSTD(nil, b)
+	bc := CompressZSTDLevel(nil, b, 5)
 	bNew, err := DecompressZSTD(nil, bc)
 	if err != nil {
 		t.Fatalf("unexpected error when decompressing b=%x from bc=%x: %s", b, bc, err)
@@ -27,7 +27,7 @@ func testCompressDecompressZSTD(t *testing.T, b []byte) {
 	}
 
 	prefix := []byte{1, 2, 33}
-	bcNew := CompressZSTD(prefix, b)
+	bcNew := CompressZSTDLevel(prefix, b, 5)
 	if string(bcNew[:len(prefix)]) != string(prefix) {
 		t.Fatalf("invalid prefix for b=%x; got\n%x; expecting\n%x", b, bcNew[:len(prefix)], prefix)
 	}

lib/encoding/encoding.go

@@ -117,7 +117,7 @@ func marshalInt64Array(dst []byte, a []int64, precisionBits uint8) (result []byt
 
 	bb := bbPool.Get()
 	if isGauge(a) {
-		// Guage values are better compressed with delta encoding.
+		// Gauge values are better compressed with delta encoding.
 		mt = MarshalTypeZSTDNearestDelta
 		pb := precisionBits
 		if pb < 6 {

lib/filestream/filestream_windows.go

@@ -0,0 +1,9 @@
+package filestream
+
+func (st *streamTracker) adviseDontNeed(n int, fdatasync bool) error {
+	return nil
+}
+
+func (st *streamTracker) close() error {
+	return nil
+}

lib/flagutil/array.go

@@ -1,18 +0,0 @@
-package flagutil
-
-import "strings"
-
-// Array holds an array of flag values
-type Array []string
-
-// String implements flag.Value interface
-func (a *Array) String() string {
-	return strings.Join(*a, ",")
-}
-
-// Set implements flag.Value interface
-func (a *Array) Set(value string) error {
-	values := strings.Split(value, ",")
-	*a = append(*a, values...)
-	return nil
-}

lib/flagutil/array_test.go

@@ -1,34 +0,0 @@
-package flagutil
-
-import (
-	"flag"
-	"os"
-	"testing"
-)
-
-var fooFlag Array
-
-func init() {
-	os.Args = append(os.Args, "--fooFlag=foo", "--fooFlag=bar")
-	flag.Var(&fooFlag, "fooFlag", "test")
-}
-
-func TestMain(m *testing.M) {
-	flag.Parse()
-	os.Exit(m.Run())
-}
-
-func TestArray(t *testing.T) {
-	expected := map[string]struct{}{
-		"foo": {},
-		"bar": {},
-	}
-	if len(expected) != len(fooFlag) {
-		t.Errorf("len array flag (%d) is not equal to %d", len(fooFlag), len(expected))
-	}
-	for _, i := range fooFlag {
-		if _, ok := expected[i]; !ok {
-			t.Errorf("unexpected item in array %v", i)
-		}
-	}
-}

lib/fs/fs.go

@@ -5,6 +5,8 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"strings"
+	"time"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/filestream"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
@@ -70,8 +72,8 @@ var (
 	readersCount = metrics.NewCounter(`vm_fs_readers`)
 )
 
-// SyncPath syncs contents of the given path.
-func SyncPath(path string) {
+// MustSyncPath syncs contents of the given path.
+func MustSyncPath(path string) {
 	d, err := os.Open(path)
 	if err != nil {
 		logger.Panicf("FATAL: cannot open %q: %s", path, err)
@@ -111,8 +113,8 @@ func WriteFile(path string, data []byte) error {
 	if err != nil {
 		return fmt.Errorf("cannot obtain absolute path to %q: %s", path, err)
 	}
-	parentDirPath, _ := filepath.Split(absPath)
-	SyncPath(parentDirPath)
+	parentDirPath := filepath.Dir(absPath)
+	MustSyncPath(parentDirPath)
 
 	return nil
 }
@@ -122,7 +124,7 @@ func MkdirAllIfNotExist(path string) error {
 	if IsPathExist(path) {
 		return nil
 	}
-	return os.MkdirAll(path, 0755)
+	return mkdirSync(path)
 }
 
 // MkdirAllFailIfExist creates the given path dir if it isn't exist.
@@ -132,7 +134,18 @@ func MkdirAllFailIfExist(path string) error {
 	if IsPathExist(path) {
 		return fmt.Errorf("the %q already exists", path)
 	}
-	return os.MkdirAll(path, 0755)
+	return mkdirSync(path)
+}
+
+func mkdirSync(path string) error {
+	if err := os.MkdirAll(path, 0755); err != nil {
+		return err
+	}
+	// Sync the parent directory, so the created directory becomes visible
+	// in the fs after power loss.
+	parentDirPath := filepath.Dir(path)
+	MustSyncPath(parentDirPath)
+	return nil
 }
 
 // RemoveDirContents removes all the contents of the given dir it it exists.
@@ -159,11 +172,9 @@ func RemoveDirContents(dir string) {
 			continue
 		}
 		fullPath := dir + "/" + name
-		if err := os.RemoveAll(fullPath); err != nil {
-			logger.Panicf("FATAL: cannot remove %q: %s", fullPath, err)
-		}
+		MustRemoveAll(fullPath)
 	}
-	SyncPath(dir)
+	MustSyncPath(dir)
 }
 
 // MustClose must close the given file f.
@@ -174,6 +185,18 @@ func MustClose(f *os.File) {
 	}
 }
 
+// MustFileSize returns file size for the given path.
+func MustFileSize(path string) uint64 {
+	fi, err := os.Stat(path)
+	if err != nil {
+		logger.Panicf("FATAL: cannot stat %q: %s", path, err)
+	}
+	if fi.IsDir() {
+		logger.Panicf("FATAL: %q must be a file, not a directory", path)
+	}
+	return uint64(fi.Size())
+}
+
 // IsPathExist returns whether the given path exists.
 func IsPathExist(path string) bool {
 	if _, err := os.Stat(path); err != nil {
@@ -185,18 +208,79 @@ func IsPathExist(path string) bool {
 	return true
 }
 
-// MustRemoveAllSynced removes path with all the contents
-// and syncs the parent directory, so it no longer contains the path.
-func MustRemoveAllSynced(path string) {
-	if err := os.RemoveAll(path); err != nil {
+func mustSyncParentDirIfExists(path string) {
+	parentDirPath := filepath.Dir(path)
+	if !IsPathExist(parentDirPath) {
+		return
+	}
+	MustSyncPath(parentDirPath)
+}
+
+// MustRemoveAll removes path with all the contents.
+//
+// It properly handles NFS issue https://github.com/VictoriaMetrics/VictoriaMetrics/issues/61 .
+func MustRemoveAll(path string) {
+	err := os.RemoveAll(path)
+	if err == nil {
+		// Make sure the parent directory doesn't contain references
+		// to the current directory.
+		mustSyncParentDirIfExists(path)
+		return
+	}
+	if !isTemporaryNFSError(err) {
 		logger.Panicf("FATAL: cannot remove %q: %s", path, err)
 	}
-	SyncPath(filepath.Dir(path))
+	// NFS prevents from removing directories with open files.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/61 .
+	// Schedule for later directory removal.
+	select {
+	case removeDirCh <- path:
+	default:
+		logger.Panicf("FATAL: cannot schedule %s for removal, since the removal queue is full (%d entries)", path, cap(removeDirCh))
+	}
+}
+
+var removeDirCh = make(chan string, 1024)
+
+func dirRemover() {
+	for path := range removeDirCh {
+		attempts := 0
+		for {
+			err := os.RemoveAll(path)
+			if err == nil {
+				break
+			}
+			if !isTemporaryNFSError(err) {
+				logger.Panicf("FATAL: cannot remove %q: %s", path, err)
+			}
+			// NFS prevents from removing directories with open files.
+			// Sleep for a while and try again in the hope open files will be closed.
+			// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/61 .
+			attempts++
+			if attempts > 10 {
+				logger.Panicf("FATAL: cannot remove %q in %d attempts: %s", path, attempts, err)
+			}
+			time.Sleep(100 * time.Millisecond)
+		}
+		// Make sure the parent directory doesn't contain references
+		// to the current directory.
+		mustSyncParentDirIfExists(path)
+	}
+}
+
+func isTemporaryNFSError(err error) bool {
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/61 for details.
+	errStr := err.Error()
+	return strings.Contains(errStr, "directory not empty") || strings.Contains(errStr, "device or resource busy")
+}
+
+func init() {
+	go dirRemover()
 }
 
 // HardLinkFiles makes hard links for all the files from srcDir in dstDir.
 func HardLinkFiles(srcDir, dstDir string) error {
-	if err := os.MkdirAll(dstDir, 0755); err != nil {
+	if err := mkdirSync(dstDir); err != nil {
 		return fmt.Errorf("cannot create dstDir=%q: %s", dstDir, err)
 	}
 
@@ -227,7 +311,7 @@ func HardLinkFiles(srcDir, dstDir string) error {
 		}
 	}
 
-	SyncPath(dstDir)
+	MustSyncPath(dstDir)
 	return nil
 }
 

lib/httpserver/httpserver.go

@@ -31,6 +31,8 @@ var (
 	httpAuthPassword = flag.String("httpAuth.password", "", "Password for HTTP Basic Auth. The authentication is disabled -httpAuth.username is empty")
 	metricsAuthKey   = flag.String("metricsAuthKey", "", "Auth key for /metrics. It overrides httpAuth settings")
 	pprofAuthKey     = flag.String("pprofAuthKey", "", "Auth key for /debug/pprof. It overrides httpAuth settings")
+
+	disableResponseCompression = flag.Bool("http.disableResponseCompression", false, "Disable compression of HTTP responses for saving CPU resources. By default compression is enabled to save network bandwidth")
 )
 
 var (
@@ -51,6 +53,8 @@ type RequestHandler func(w http.ResponseWriter, r *http.Request) bool
 // By default all the responses are transparently compressed, since Google
 // charges a lot for the egress traffic. The compression may be disabled
 // by calling DisableResponseCompression before writing the first byte to w.
+//
+// The compression is also disabled if -http.disableResponseCompression flag is set.
 func Serve(addr string, rh RequestHandler) {
 	scheme := "http"
 	if *tlsEnable {
@@ -224,6 +228,9 @@ func checkBasicAuth(w http.ResponseWriter, r *http.Request) bool {
 }
 
 func maybeGzipResponseWriter(w http.ResponseWriter, r *http.Request) http.ResponseWriter {
+	if *disableResponseCompression {
+		return w
+	}
 	ae := r.Header.Get("Accept-Encoding")
 	if ae == "" {
 		return w

lib/memory/memory_linux.go

@@ -2,6 +2,7 @@ package memory
 
 import (
 	"io/ioutil"
+	"os/exec"
 	"strconv"
 	"syscall"
 
@@ -19,17 +20,57 @@ func sysTotalMemory() int {
 	// See https://stackoverflow.com/questions/42187085/check-mem-limit-within-a-docker-container .
 	data, err := ioutil.ReadFile("/sys/fs/cgroup/memory/memory.limit_in_bytes")
 	if err != nil {
-		return totalMem
+		// Try determining the amount of memory inside lxc container.
+		mem, err := readLXCMemoryLimit(totalMem)
+		if err != nil {
+			return totalMem
+		}
+		return mem
 	}
-	for len(data) > 0 && data[len(data)-1] == '\n' {
-		data = data[:len(data)-1]
-	}
-	mem, err := strconv.Atoi(string(data))
+	mem, err := readPositiveInt(data, totalMem)
 	if err != nil {
 		return totalMem
 	}
-	if mem > totalMem {
-		mem = totalMem
+	if mem != totalMem {
+		return mem
+	}
+
+	// Try reading LXC memory limit, since it looks like the cgroup limit doesn't work
+	mem, err = readLXCMemoryLimit(totalMem)
+	if err != nil {
+		return totalMem
 	}
 	return mem
 }
+
+func readLXCMemoryLimit(totalMem int) (int, error) {
+	// Read memory limit according to https://unix.stackexchange.com/questions/242718/how-to-find-out-how-much-memory-lxc-container-is-allowed-to-consume
+	// This should properly determine the limit inside lxc container.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/84
+	cmd := exec.Command("/bin/sh", "-c",
+		`cat /sys/fs/cgroup/memory$(cat /proc/self/cgroup | grep memory | cut -d: -f3)/memory.limit_in_bytes`)
+	data, err := cmd.Output()
+	if err != nil {
+		return 0, err
+	}
+	return readPositiveInt(data, totalMem)
+}
+
+func readPositiveInt(data []byte, maxN int) (int, error) {
+	for len(data) > 0 && data[len(data)-1] == '\n' {
+		data = data[:len(data)-1]
+	}
+	n, err := strconv.ParseUint(string(data), 10, 64)
+	if err != nil {
+		return 0, err
+	}
+	if int64(n) < 0 || int64(int(n)) != int64(n) {
+		// Int overflow.
+		return maxN, nil
+	}
+	ni := int(n)
+	if ni > maxN {
+		return maxN, nil
+	}
+	return ni, nil
+}

lib/memory/memory_windows.go

@@ -0,0 +1,40 @@
+package memory
+
+import (
+	"syscall"
+	"unsafe"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+)
+
+// This has been adapted from https://github.com/pbnjay/memory.
+
+type memStatusEx struct {
+	dwLength     uint32
+	dwMemoryLoad uint32
+	ullTotalPhys uint64
+	unused       [6]uint64
+}
+
+func sysTotalMemory() int {
+	kernel32, err := syscall.LoadDLL("kernel32.dll")
+	if err != nil {
+		logger.Panicf("FATAL: cannot load kernel32.dll: %s", err)
+	}
+	globalMemoryStatusEx, err := kernel32.FindProc("GlobalMemoryStatusEx")
+	if err != nil {
+		logger.Panicf("FATAL: cannot find GlobalMemoryStatusEx: %s", err)
+	}
+	msx := &memStatusEx{
+		dwLength: uint32(unsafe.Sizeof(memStatusEx{})),
+	}
+	r, _, err := globalMemoryStatusEx.Call(uintptr(unsafe.Pointer(msx)))
+	if r == 0 {
+		logger.Panicf("FATAL: error in GlobalMemoryStatusEx: %s", err)
+	}
+	n := int(msx.ullTotalPhys)
+	if uint64(n) != msx.ullTotalPhys {
+		logger.Panicf("FATAL: int overflow for msx.ullTotalPhys=%d", msx.ullTotalPhys)
+	}
+	return n
+}

lib/mergeset/block_stream_reader.go

@@ -91,6 +91,13 @@ func (bsr *blockStreamReader) reset() {
 	bsr.err = nil
 }
 
+func (bsr *blockStreamReader) String() string {
+	if len(bsr.path) > 0 {
+		return bsr.path
+	}
+	return bsr.ph.String()
+}
+
 // InitFromInmemoryPart initializes bsr from the given ip.
 func (bsr *blockStreamReader) InitFromInmemoryPart(ip *inmemoryPart) {
 	bsr.reset()

lib/mergeset/block_stream_writer.go

@@ -2,7 +2,6 @@ package mergeset
 
 import (
 	"fmt"
-	"os"
 	"path/filepath"
 	"sync"
 
@@ -92,7 +91,7 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 	metaindexPath := path + "/metaindex.bin"
 	metaindexFile, err := filestream.Create(metaindexPath, false)
 	if err != nil {
-		_ = os.RemoveAll(path)
+		fs.MustRemoveAll(path)
 		return fmt.Errorf("cannot create metaindex file: %s", err)
 	}
 
@@ -100,7 +99,7 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 	indexFile, err := filestream.Create(indexPath, nocache)
 	if err != nil {
 		metaindexFile.MustClose()
-		_ = os.RemoveAll(path)
+		fs.MustRemoveAll(path)
 		return fmt.Errorf("cannot create index file: %s", err)
 	}
 
@@ -109,7 +108,7 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 	if err != nil {
 		metaindexFile.MustClose()
 		indexFile.MustClose()
-		_ = os.RemoveAll(path)
+		fs.MustRemoveAll(path)
 		return fmt.Errorf("cannot create items file: %s", err)
 	}
 
@@ -119,7 +118,7 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 		metaindexFile.MustClose()
 		indexFile.MustClose()
 		itemsFile.MustClose()
-		_ = os.RemoveAll(path)
+		fs.MustRemoveAll(path)
 		return fmt.Errorf("cannot create lens file: %s", err)
 	}
 
@@ -152,6 +151,12 @@ func (bsw *blockStreamWriter) MustClose() {
 	bsw.itemsWriter.MustClose()
 	bsw.lensWriter.MustClose()
 
+	// Sync bsw.path contents to make sure it doesn't disappear
+	// after system crash or power loss.
+	if bsw.path != "" {
+		fs.MustSyncPath(bsw.path)
+	}
+
 	bsw.reset()
 }
 

lib/mergeset/inmemory_part.go

@@ -84,13 +84,18 @@ func (ip *inmemoryPart) Init(ib *inmemoryBlock) {
 // It is unsafe re-using ip while the returned part is in use.
 func (ip *inmemoryPart) NewPart() *part {
 	ph := ip.ph
-	p, err := newPart(&ph, "", ip.metaindexData.NewReader(), &ip.indexData, &ip.itemsData, &ip.lensData)
+	size := ip.size()
+	p, err := newPart(&ph, "", size, ip.metaindexData.NewReader(), &ip.indexData, &ip.itemsData, &ip.lensData)
 	if err != nil {
 		logger.Panicf("BUG: cannot create a part from inmemoryPart: %s", err)
 	}
 	return p
 }
 
+func (ip *inmemoryPart) size() uint64 {
+	return uint64(len(ip.metaindexData.B) + len(ip.indexData.B) + len(ip.itemsData.B) + len(ip.lensData.B))
+}
+
 func getInmemoryPart() *inmemoryPart {
 	v := ipPool.Get()
 	if v == nil {

lib/mergeset/merge.go

@@ -29,7 +29,7 @@ func mergeBlockStreams(ph *partHeader, bsw *blockStreamWriter, bsrs []*blockStre
 	if err == errForciblyStopped {
 		return err
 	}
-	return fmt.Errorf("cannot merge block streams: %s", err)
+	return fmt.Errorf("cannot merge %d block streams: %s: %s", len(bsrs), bsrs, err)
 }
 
 var bsmPool = &sync.Pool{

lib/mergeset/part.go

@@ -48,6 +48,8 @@ type part struct {
 
 	path string
 
+	size uint64
+
 	mrs []metaindexRow
 
 	indexFile fs.ReadAtCloser
@@ -71,6 +73,7 @@ func openFilePart(path string) (*part, error) {
 	if err != nil {
 		return nil, fmt.Errorf("cannot open %q: %s", metaindexPath, err)
 	}
+	metaindexSize := fs.MustFileSize(metaindexPath)
 
 	indexPath := path + "/index.bin"
 	indexFile, err := fs.OpenReaderAt(indexPath)
@@ -78,6 +81,7 @@ func openFilePart(path string) (*part, error) {
 		metaindexFile.MustClose()
 		return nil, fmt.Errorf("cannot open %q: %s", indexPath, err)
 	}
+	indexSize := fs.MustFileSize(indexPath)
 
 	itemsPath := path + "/items.bin"
 	itemsFile, err := fs.OpenReaderAt(itemsPath)
@@ -86,6 +90,7 @@ func openFilePart(path string) (*part, error) {
 		indexFile.MustClose()
 		return nil, fmt.Errorf("cannot open %q: %s", itemsPath, err)
 	}
+	itemsSize := fs.MustFileSize(itemsPath)
 
 	lensPath := path + "/lens.bin"
 	lensFile, err := fs.OpenReaderAt(lensPath)
@@ -95,11 +100,13 @@ func openFilePart(path string) (*part, error) {
 		itemsFile.MustClose()
 		return nil, fmt.Errorf("cannot open %q: %s", lensPath, err)
 	}
+	lensSize := fs.MustFileSize(lensPath)
 
-	return newPart(&ph, path, metaindexFile, indexFile, itemsFile, lensFile)
+	size := metaindexSize + indexSize + itemsSize + lensSize
+	return newPart(&ph, path, size, metaindexFile, indexFile, itemsFile, lensFile)
 }
 
-func newPart(ph *partHeader, path string, metaindexReader filestream.ReadCloser, indexFile, itemsFile, lensFile fs.ReadAtCloser) (*part, error) {
+func newPart(ph *partHeader, path string, size uint64, metaindexReader filestream.ReadCloser, indexFile, itemsFile, lensFile fs.ReadAtCloser) (*part, error) {
 	var errors []error
 	mrs, err := unmarshalMetaindexRows(nil, metaindexReader)
 	if err != nil {
@@ -109,6 +116,7 @@ func newPart(ph *partHeader, path string, metaindexReader filestream.ReadCloser,
 
 	p := &part{
 		path: path,
+		size: size,
 		mrs:  mrs,
 
 		indexFile: indexFile,

lib/mergeset/part_search.go

@@ -356,16 +356,15 @@ func (ps *partSearch) readInmemoryBlock(bh *blockHeader) (*inmemoryBlock, error)
 }
 
 func binarySearchKey(items [][]byte, key []byte) int {
-	if len(items) > 0 {
-		if string(key) <= string(items[0]) {
-			// Fast path - the item is the first.
-			return 0
-		}
-		if len(items) > 1 && string(key) <= string(items[1]) {
-			// Fast path - the item is the second.
-			return 1
-		}
+	if len(items) == 0 {
+		return 0
 	}
+	if string(key) <= string(items[0]) {
+		// Fast path - the item is the first.
+		return 0
+	}
+	items = items[1:]
+	offset := uint(1)
 
 	// This has been copy-pasted from https://golang.org/src/sort/search.go
 	n := uint(len(items))
@@ -378,5 +377,5 @@ func binarySearchKey(items [][]byte, key []byte) int {
 			j = h
 		}
 	}
-	return int(i)
+	return int(i + offset)
 }

lib/mergeset/part_search_test.go

@@ -156,7 +156,8 @@ func newTestPart(blocksCount, maxItemsPerBlock int) (*part, []string, error) {
 	if itemsMerged != uint64(len(items)) {
 		return nil, nil, fmt.Errorf("unexpected itemsMerged; got %d; want %d", itemsMerged, len(items))
 	}
-	p, err := newPart(&ip.ph, "partName", ip.metaindexData.NewReader(), &ip.indexData, &ip.itemsData, &ip.lensData)
+	size := ip.size()
+	p, err := newPart(&ip.ph, "partName", size, ip.metaindexData.NewReader(), &ip.indexData, &ip.itemsData, &ip.lensData)
 	if err != nil {
 		return nil, nil, fmt.Errorf("cannot create part: %s", err)
 	}

lib/mergeset/table.go

@@ -161,8 +161,8 @@ func OpenTable(path string) (*Table, error) {
 
 	var m TableMetrics
 	tb.UpdateMetrics(&m)
-	logger.Infof("table %q has been opened in %s; partsCount: %d; blocksCount: %d, itemsCount: %d",
-		path, time.Since(startTime), m.PartsCount, m.BlocksCount, m.ItemsCount)
+	logger.Infof("table %q has been opened in %s; partsCount: %d; blocksCount: %d, itemsCount: %d; sizeBytes: %d",
+		path, time.Since(startTime), m.PartsCount, m.BlocksCount, m.ItemsCount, m.SizeBytes)
 
 	return tb, nil
 }
@@ -208,7 +208,7 @@ func (tb *Table) MustClose() {
 	logger.Infof("%d inmemory parts have been flushed to files in %s on %q", len(pws), time.Since(startTime), tb.path)
 
 	// Remove references to parts from the tb, so they may be eventually closed
-	// after all the seraches are done.
+	// after all the searches are done.
 	tb.partsLock.Lock()
 	parts := tb.parts
 	tb.parts = nil
@@ -242,6 +242,7 @@ type TableMetrics struct {
 
 	BlocksCount uint64
 	ItemsCount  uint64
+	SizeBytes   uint64
 
 	DataBlocksCacheSize     uint64
 	DataBlocksCacheRequests uint64
@@ -274,6 +275,7 @@ func (tb *Table) UpdateMetrics(m *TableMetrics) {
 
 		m.BlocksCount += p.ph.blocksCount
 		m.ItemsCount += p.ph.itemsCount
+		m.SizeBytes += p.size
 
 		m.DataBlocksCacheSize += p.ibCache.Len()
 		m.DataBlocksCacheRequests += p.ibCache.Requests()
@@ -727,6 +729,7 @@ func (tb *Table) mergeParts(pws []*partWrapper, stopCh <-chan struct{}, isOuterP
 	if err != nil {
 		return fmt.Errorf("cannot open merged part %q: %s", dstPartPath, err)
 	}
+	newPSize := newP.size
 	newPW := &partWrapper{
 		p:        newP,
 		refCount: 1,
@@ -761,7 +764,7 @@ func (tb *Table) mergeParts(pws []*partWrapper, stopCh <-chan struct{}, isOuterP
 
 	d := time.Since(startTime)
 	if d > 10*time.Second {
-		logger.Infof("merged %d items in %s at %d items/sec to %q", outItemsCount, d, int(float64(outItemsCount)/d.Seconds()), dstPartPath)
+		logger.Infof("merged %d items in %s at %d items/sec to %q; sizeBytes: %d", outItemsCount, d, int(float64(outItemsCount)/d.Seconds()), dstPartPath, newPSize)
 	}
 
 	return nil
@@ -846,22 +849,18 @@ func openParts(path string) ([]*partWrapper, error) {
 	}
 
 	txnDir := path + "/txn"
-	if err := os.RemoveAll(txnDir); err != nil {
-		return nil, fmt.Errorf("cannot remove %q: %s", txnDir, err)
-	}
+	fs.MustRemoveAll(txnDir)
 	if err := fs.MkdirAllFailIfExist(txnDir); err != nil {
 		return nil, fmt.Errorf("cannot create %q: %s", txnDir, err)
 	}
 
 	tmpDir := path + "/tmp"
-	if err := os.RemoveAll(tmpDir); err != nil {
-		return nil, fmt.Errorf("cannot remove %q: %s", tmpDir, err)
-	}
+	fs.MustRemoveAll(tmpDir)
 	if err := fs.MkdirAllFailIfExist(tmpDir); err != nil {
 		return nil, fmt.Errorf("cannot create %q: %s", tmpDir, err)
 	}
 
-	fs.SyncPath(path)
+	fs.MustSyncPath(path)
 
 	// Open parts.
 	fis, err := d.Readdir(-1)
@@ -965,9 +964,9 @@ func (tb *Table) CreateSnapshotAt(dstDir string) error {
 		}
 	}
 
-	fs.SyncPath(dstDir)
+	fs.MustSyncPath(dstDir)
 	parentDir := filepath.Dir(dstDir)
-	fs.SyncPath(parentDir)
+	fs.MustSyncPath(parentDir)
 
 	logger.Infof("created Table snapshot of %q at %q in %s", srcDir, dstDir, time.Since(startTime))
 	return nil
@@ -1033,9 +1032,7 @@ func runTransaction(txnLock *sync.RWMutex, pathPrefix, txnPath string) error {
 		if err != nil {
 			return fmt.Errorf("invalid path to remove: %s", err)
 		}
-		if err := os.RemoveAll(path); err != nil {
-			return fmt.Errorf("cannot remove %q: %s", path, err)
-		}
+		fs.MustRemoveAll(path)
 	}
 
 	// Move the new part to new directory.
@@ -1061,7 +1058,7 @@ func runTransaction(txnLock *sync.RWMutex, pathPrefix, txnPath string) error {
 	}
 
 	// Flush pathPrefix directory metadata to the underying storage.
-	fs.SyncPath(pathPrefix)
+	fs.MustSyncPath(pathPrefix)
 
 	// Remove the transaction file.
 	if err := os.Remove(txnPath); err != nil {

lib/mergeset/table_search_timing_test.go

@@ -33,6 +33,9 @@ func benchmarkTableSearch(b *testing.B, itemsCount int) {
 	// Force finishing pending merges
 	tb.MustClose()
 	tb, err = OpenTable(path)
+	if err != nil {
+		b.Fatalf("unexpected error when re-opening table %q: %s", path, err)
+	}
 	defer tb.MustClose()
 
 	keys := make([][]byte, len(items))

lib/netutil/tcplistener.go

@@ -47,8 +47,6 @@ type TCPListener struct {
 
 	net.Listener
 
-	name string
-
 	accepts      *metrics.Counter
 	acceptErrors *metrics.Counter
 

lib/procutil/signal.go

@@ -6,7 +6,7 @@ import (
 	"syscall"
 )
 
-// WaitForSigterm waits fro either SIGTERM or SIGINT
+// WaitForSigterm waits for either SIGTERM or SIGINT
 //
 // Returns the caught signal.
 func WaitForSigterm() os.Signal {

lib/prompb/util.go

@@ -11,13 +11,9 @@ import (
 // ReadSnappy reads r, unpacks it using snappy, appends it to dst
 // and returns the result.
 func ReadSnappy(dst []byte, r io.Reader, maxSize int64) ([]byte, error) {
-	bb := bodyBufferPool.Get()
-	bb.B = bb.B[:0]
-	cb := copyBufferPool.Get()
-	cb.B = bytesutil.Resize(cb.B, 16*1024)
 	lr := io.LimitReader(r, maxSize+1)
-	reqLen, err := io.CopyBuffer(bb, lr, cb.B)
-	copyBufferPool.Put(cb)
+	bb := bodyBufferPool.Get()
+	reqLen, err := bb.ReadFrom(lr)
 	if err != nil {
 		bodyBufferPool.Put(bb)
 		return dst, fmt.Errorf("cannot read compressed request: %s", err)
@@ -45,7 +41,6 @@ func ReadSnappy(dst []byte, r io.Reader, maxSize int64) ([]byte, error) {
 }
 
 var bodyBufferPool bytesutil.ByteBufferPool
-var copyBufferPool bytesutil.ByteBufferPool
 
 // Reset resets wr.
 func (wr *WriteRequest) Reset() {

lib/storage/block_stream_writer.go

@@ -2,7 +2,6 @@ package storage
 
 import (
 	"fmt"
-	"os"
 	"path/filepath"
 	"sync"
 	"sync/atomic"
@@ -85,7 +84,7 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 	timestampsPath := path + "/timestamps.bin"
 	timestampsFile, err := filestream.Create(timestampsPath, nocache)
 	if err != nil {
-		_ = os.RemoveAll(path)
+		fs.MustRemoveAll(path)
 		return fmt.Errorf("cannot create timestamps file: %s", err)
 	}
 
@@ -93,7 +92,7 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 	valuesFile, err := filestream.Create(valuesPath, nocache)
 	if err != nil {
 		timestampsFile.MustClose()
-		_ = os.RemoveAll(path)
+		fs.MustRemoveAll(path)
 		return fmt.Errorf("cannot create values file: %s", err)
 	}
 
@@ -102,7 +101,7 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 	if err != nil {
 		timestampsFile.MustClose()
 		valuesFile.MustClose()
-		_ = os.RemoveAll(path)
+		fs.MustRemoveAll(path)
 		return fmt.Errorf("cannot create index file: %s", err)
 	}
 
@@ -114,7 +113,7 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 		timestampsFile.MustClose()
 		valuesFile.MustClose()
 		indexFile.MustClose()
-		_ = os.RemoveAll(path)
+		fs.MustRemoveAll(path)
 		return fmt.Errorf("cannot create metaindex file: %s", err)
 	}
 
@@ -147,6 +146,12 @@ func (bsw *blockStreamWriter) MustClose() {
 	bsw.indexWriter.MustClose()
 	bsw.metaindexWriter.MustClose()
 
+	// Sync bsw.path contents to make sure it doesn't disappear
+	// after system crash or power loss.
+	if bsw.path != "" {
+		fs.MustSyncPath(bsw.path)
+	}
+
 	bsw.reset()
 }
 

lib/storage/index_db.go

@@ -5,7 +5,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"os"
 	"path/filepath"
 	"sort"
 	"sync"
@@ -15,6 +14,7 @@ import (
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/encoding"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fs"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/memory"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/mergeset"
@@ -60,6 +60,10 @@ type indexDB struct {
 	// Cache for fast MetricID -> MetricName lookup.
 	metricNameCache *fastcache.Cache
 
+	// Cache holding useless TagFilters entries, which have no tag filters
+	// matching low number of metrics.
+	uselessTagFiltersCache *fastcache.Cache
+
 	indexSearchPool sync.Pool
 
 	// An inmemory map[uint64]struct{} of deleted metricIDs.
@@ -71,15 +75,46 @@ type indexDB struct {
 	deletedMetricIDs           atomic.Value
 	deletedMetricIDsUpdateLock sync.Mutex
 
+	// Global lists of metric ids for the current and the previous hours.
+	// They are used for fast lookups on small time ranges covering
+	// up to two last hours.
+	currHourMetricIDs *atomic.Value
+	prevHourMetricIDs *atomic.Value
+
 	// The number of missing MetricID -> TSID entries.
 	// High rate for this value means corrupted indexDB.
 	missingTSIDsForMetricID uint64
 
+	// The number of calls to search for metric ids for recent hours.
+	recentHourMetricIDsSearchCalls uint64
+
+	// The number of cache hits during search for metric ids in recent hours.
+	recentHourMetricIDsSearchHits uint64
+
+	// The number of searches for metric ids by days.
+	dateMetricIDsSearchCalls uint64
+
+	// The number of successful searches for metric ids by days.
+	dateMetricIDsSearchHits uint64
+
 	mustDrop uint64
 }
 
 // openIndexDB opens index db from the given path with the given caches.
-func openIndexDB(path string, metricIDCache, metricNameCache *fastcache.Cache) (*indexDB, error) {
+func openIndexDB(path string, metricIDCache, metricNameCache *fastcache.Cache, currHourMetricIDs, prevHourMetricIDs *atomic.Value) (*indexDB, error) {
+	if metricIDCache == nil {
+		logger.Panicf("BUG: metricIDCache must be non-nil")
+	}
+	if metricNameCache == nil {
+		logger.Panicf("BUG: metricNameCache must be non-nil")
+	}
+	if currHourMetricIDs == nil {
+		logger.Panicf("BUG: currHourMetricIDs must be non-nil")
+	}
+	if prevHourMetricIDs == nil {
+		logger.Panicf("BUG: prevHourMetricIDs must be non-nil")
+	}
+
 	tb, err := mergeset.OpenTable(path)
 	if err != nil {
 		return nil, fmt.Errorf("cannot open indexDB %q: %s", path, err)
@@ -89,16 +124,19 @@ func openIndexDB(path string, metricIDCache, metricNameCache *fastcache.Cache) (
 
 	// Do not persist tagCache in files, since it is very volatile.
 	mem := memory.Allowed()
-	tagCache := fastcache.New(mem / 32)
 
 	db := &indexDB{
 		refCount: 1,
 		tb:       tb,
 		name:     name,
 
-		tagCache:        tagCache,
-		metricIDCache:   metricIDCache,
-		metricNameCache: metricNameCache,
+		tagCache:               fastcache.New(mem / 32),
+		metricIDCache:          metricIDCache,
+		metricNameCache:        metricNameCache,
+		uselessTagFiltersCache: fastcache.New(mem / 128),
+
+		currHourMetricIDs: currHourMetricIDs,
+		prevHourMetricIDs: prevHourMetricIDs,
 	}
 
 	is := db.getIndexSearch()
@@ -115,16 +153,26 @@ func openIndexDB(path string, metricIDCache, metricNameCache *fastcache.Cache) (
 // IndexDBMetrics contains essential metrics for indexDB.
 type IndexDBMetrics struct {
 	TagCacheSize      uint64
-	TagCacheBytesSize uint64
+	TagCacheSizeBytes uint64
 	TagCacheRequests  uint64
 	TagCacheMisses    uint64
 
+	UselessTagFiltersCacheSize      uint64
+	UselessTagFiltersCacheSizeBytes uint64
+	UselessTagFiltersCacheRequests  uint64
+	UselessTagFiltersCacheMisses    uint64
+
 	DeletedMetricsCount uint64
 
 	IndexDBRefCount uint64
 
 	MissingTSIDsForMetricID uint64
 
+	RecentHourMetricIDsSearchCalls uint64
+	RecentHourMetricIDsSearchHits  uint64
+	DateMetricIDsSearchCalls       uint64
+	DateMetricIDsSearchHits        uint64
+
 	mergeset.TableMetrics
 }
 
@@ -135,16 +183,29 @@ func (db *indexDB) scheduleToDrop() {
 // UpdateMetrics updates m with metrics from the db.
 func (db *indexDB) UpdateMetrics(m *IndexDBMetrics) {
 	var cs fastcache.Stats
+
+	cs.Reset()
 	db.tagCache.UpdateStats(&cs)
 	m.TagCacheSize += cs.EntriesCount
-	m.TagCacheBytesSize += cs.BytesSize
+	m.TagCacheSizeBytes += cs.BytesSize
 	m.TagCacheRequests += cs.GetBigCalls
 	m.TagCacheMisses += cs.Misses
 
+	cs.Reset()
+	db.uselessTagFiltersCache.UpdateStats(&cs)
+	m.UselessTagFiltersCacheSize += cs.EntriesCount
+	m.UselessTagFiltersCacheSizeBytes += cs.BytesSize
+	m.UselessTagFiltersCacheRequests += cs.GetBigCalls
+	m.UselessTagFiltersCacheMisses += cs.Misses
+
 	m.DeletedMetricsCount += uint64(len(db.getDeletedMetricIDs()))
 
 	m.IndexDBRefCount += atomic.LoadUint64(&db.refCount)
 	m.MissingTSIDsForMetricID += atomic.LoadUint64(&db.missingTSIDsForMetricID)
+	m.RecentHourMetricIDsSearchCalls += atomic.LoadUint64(&db.recentHourMetricIDsSearchCalls)
+	m.RecentHourMetricIDsSearchHits += atomic.LoadUint64(&db.recentHourMetricIDsSearchHits)
+	m.DateMetricIDsSearchCalls += atomic.LoadUint64(&db.dateMetricIDsSearchCalls)
+	m.DateMetricIDsSearchHits += atomic.LoadUint64(&db.dateMetricIDsSearchHits)
 
 	db.tb.UpdateMetrics(&m.TableMetrics)
 	db.doExtDB(func(extDB *indexDB) {
@@ -200,7 +261,7 @@ func (db *indexDB) incRef() {
 
 func (db *indexDB) decRef() {
 	n := atomic.AddUint64(&db.refCount, ^uint64(0))
-	if n < 0 {
+	if int64(n) < 0 {
 		logger.Panicf("BUG: negative refCount: %d", n)
 	}
 	if n > 0 {
@@ -211,14 +272,21 @@ func (db *indexDB) decRef() {
 	db.tb.MustClose()
 	db.SetExtDB(nil)
 
+	// Free space occupied by caches owned by db.
+	db.tagCache.Reset()
+	db.uselessTagFiltersCache.Reset()
+
+	db.tagCache = nil
+	db.metricIDCache = nil
+	db.metricNameCache = nil
+	db.uselessTagFiltersCache = nil
+
 	if atomic.LoadUint64(&db.mustDrop) == 0 {
 		return
 	}
 
 	logger.Infof("dropping indexDB %q", tbPath)
-	if err := os.RemoveAll(tbPath); err != nil {
-		logger.Panicf("FATAL: cannot remove %q: %s", tbPath, err)
-	}
+	fs.MustRemoveAll(tbPath)
 	logger.Infof("indexDB %q has been dropped", tbPath)
 }
 
@@ -273,8 +341,11 @@ func (db *indexDB) putMetricNameToCache(metricID uint64, metricName []byte) {
 	db.metricNameCache.Set(key[:], metricName)
 }
 
-func marshalTagFiltersKey(dst []byte, tfss []*TagFilters) []byte {
-	prefix := atomic.LoadUint64(&tagFiltersKeyGen)
+func marshalTagFiltersKey(dst []byte, tfss []*TagFilters, versioned bool) []byte {
+	prefix := ^uint64(0)
+	if versioned {
+		prefix = atomic.LoadUint64(&tagFiltersKeyGen)
+	}
 	dst = encoding.MarshalUint64(dst, prefix)
 	for _, tfs := range tfss {
 		dst = append(dst, 0) // separator between tfs groups.
@@ -718,7 +789,7 @@ func (is *indexSearch) searchTagValues(tvs map[string]struct{}, prefix []byte, m
 // up to two times - in db and extDB.
 func (db *indexDB) GetSeriesCount() (uint64, error) {
 	is := db.getIndexSearch()
-	n, err := getSeriesCount(&is.ts, &is.kb)
+	n, err := is.getSeriesCount()
 	db.putIndexSearch(is)
 	if err != nil {
 		return 0, err
@@ -727,7 +798,7 @@ func (db *indexDB) GetSeriesCount() (uint64, error) {
 	var nExt uint64
 	ok := db.doExtDB(func(extDB *indexDB) {
 		is := extDB.getIndexSearch()
-		nExt, err = getSeriesCount(&is.ts, &is.kb)
+		nExt, err = is.getSeriesCount()
 		extDB.putIndexSearch(is)
 	})
 	if ok && err != nil {
@@ -872,7 +943,7 @@ func (db *indexDB) searchTSIDs(tfss []*TagFilters, tr TimeRange, maxMetrics int)
 	tfKeyBuf := tagFiltersKeyBufPool.Get()
 	defer tagFiltersKeyBufPool.Put(tfKeyBuf)
 
-	tfKeyBuf.B = marshalTagFiltersKey(tfKeyBuf.B[:0], tfss)
+	tfKeyBuf.B = marshalTagFiltersKey(tfKeyBuf.B[:0], tfss, true)
 	tsids, ok := db.getFromTagCache(tfKeyBuf.B)
 	if ok {
 		// Fast path - tsids found in the cache.
@@ -889,7 +960,12 @@ func (db *indexDB) searchTSIDs(tfss []*TagFilters, tr TimeRange, maxMetrics int)
 
 	var extTSIDs []TSID
 	if db.doExtDB(func(extDB *indexDB) {
-		tsids, ok := extDB.getFromTagCache(tfKeyBuf.B)
+		tfKeyExtBuf := tagFiltersKeyBufPool.Get()
+		defer tagFiltersKeyBufPool.Put(tfKeyExtBuf)
+
+		// Data in extDB cannot be changed, so use unversioned keys for tag cache.
+		tfKeyExtBuf.B = marshalTagFiltersKey(tfKeyExtBuf.B[:0], tfss, false)
+		tsids, ok := extDB.getFromTagCache(tfKeyExtBuf.B)
 		if ok {
 			extTSIDs = tsids
 			return
@@ -898,8 +974,7 @@ func (db *indexDB) searchTSIDs(tfss []*TagFilters, tr TimeRange, maxMetrics int)
 		extTSIDs, err = is.searchTSIDs(tfss, tr, maxMetrics)
 		extDB.putIndexSearch(is)
 
-		// Do not store found tsids into extDB.tagCache,
-		// since they will be stored into outer cache instead.
+		db.putToTagCache(tsids, tfKeyExtBuf.B)
 	}) {
 		if err != nil {
 			return nil, err
@@ -945,7 +1020,7 @@ func (is *indexSearch) getTSIDByMetricName(dst *TSID, metricName []byte) error {
 		if len(dmis) > 0 {
 			// Verify whether the dst is marked as deleted.
 			if _, deleted := dmis[dst.MetricID]; deleted {
-				// The dst is deleted. Continue seraching.
+				// The dst is deleted. Continue searching.
 				continue
 			}
 		}
@@ -1009,6 +1084,15 @@ func mergeTSIDs(a, b []TSID) []TSID {
 }
 
 func (is *indexSearch) searchTSIDs(tfss []*TagFilters, tr TimeRange, maxMetrics int) ([]TSID, error) {
+	// Verify whether `is` contains data for the given tr.
+	ok, err := is.containsTimeRange(tr)
+	if err != nil {
+		return nil, fmt.Errorf("error in containsTimeRange(%s): %s", &tr, err)
+	}
+	if !ok {
+		// Fast path: nothing to search.
+		return nil, nil
+	}
 	metricIDs, err := is.searchMetricIDs(tfss, tr, maxMetrics)
 	if err != nil {
 		return nil, err
@@ -1078,7 +1162,9 @@ func (is *indexSearch) getTSIDByMetricID(dst *TSID, metricID uint64) error {
 	return nil
 }
 
-func getSeriesCount(ts *mergeset.TableSearch, kb *bytesutil.ByteBuffer) (uint64, error) {
+func (is *indexSearch) getSeriesCount() (uint64, error) {
+	ts := &is.ts
+	kb := &is.kb
 	var n uint64
 	kb.B = append(kb.B[:0], nsPrefixMetricIDToTSID)
 	ts.Seek(kb.B)
@@ -1095,9 +1181,9 @@ func getSeriesCount(ts *mergeset.TableSearch, kb *bytesutil.ByteBuffer) (uint64,
 	return n, nil
 }
 
-// searchMetricIDsMapByMetricNameMatch matches metricName values for the given srcMetricIDs against tfs
+// updateMetricIDsByMetricNameMatch matches metricName values for the given srcMetricIDs against tfs
 // and adds matching metrics to metricIDs.
-func (is *indexSearch) searchMetricIDsMapByMetricNameMatch(metricIDs, srcMetricIDs map[uint64]struct{}, tfs []*tagFilter) error {
+func (is *indexSearch) updateMetricIDsByMetricNameMatch(metricIDs, srcMetricIDs map[uint64]struct{}, tfs []*tagFilter) error {
 	// sort srcMetricIDs in order to speed up Seek below.
 	sortedMetricIDs := make([]uint64, 0, len(srcMetricIDs))
 	for metricID := range srcMetricIDs {
@@ -1132,16 +1218,91 @@ func (is *indexSearch) searchMetricIDsMapByMetricNameMatch(metricIDs, srcMetricI
 	return nil
 }
 
-func (is *indexSearch) getTagFilterWithMinMetricIDsMap(tfs *TagFilters, maxMetrics int) (*tagFilter, map[uint64]struct{}, error) {
+func (is *indexSearch) getTagFilterWithMinMetricIDsCountAdaptive(tfs *TagFilters, maxMetrics int) (*tagFilter, map[uint64]struct{}, error) {
+	maxMetrics = is.adjustMaxMetricsAdaptive(maxMetrics)
+	kb := &is.kb
+	kb.B = append(kb.B[:0], uselessMultiTagFiltersKeyPrefix)
+	kb.B = encoding.MarshalUint64(kb.B, uint64(maxMetrics))
+	kb.B = tfs.marshal(kb.B)
+	if len(is.db.uselessTagFiltersCache.Get(nil, kb.B)) > 0 {
+		// Skip useless work below, since the tfs doesn't contain tag filters matching less than maxMetrics metrics.
+		return nil, nil, errTooManyMetrics
+	}
+
+	// Iteratively increase maxAllowedMetrics up to maxMetrics in order to limit
+	// the time required for founding the tag filter with minimum matching metrics.
+	maxAllowedMetrics := 16
+	if maxAllowedMetrics > maxMetrics {
+		maxAllowedMetrics = maxMetrics
+	}
+	for {
+		minTf, minMetricIDs, err := is.getTagFilterWithMinMetricIDsCount(tfs, maxAllowedMetrics)
+		if err != errTooManyMetrics {
+			if err != nil {
+				return nil, nil, err
+			}
+			if len(minMetricIDs) < maxAllowedMetrics {
+				// Found the tag filter with the minimum number of metrics.
+				return minTf, minMetricIDs, nil
+			}
+		}
+
+		// Too many metrics matched.
+		if maxAllowedMetrics >= maxMetrics {
+			// The tag filter with minimum matching metrics matches at least maxMetrics metrics.
+			kb.B = append(kb.B[:0], uselessMultiTagFiltersKeyPrefix)
+			kb.B = encoding.MarshalUint64(kb.B, uint64(maxMetrics))
+			kb.B = tfs.marshal(kb.B)
+			is.db.uselessTagFiltersCache.Set(kb.B, uselessTagFilterCacheValue)
+			return nil, nil, errTooManyMetrics
+		}
+
+		// Increase maxAllowedMetrics and try again.
+		maxAllowedMetrics *= 4
+		if maxAllowedMetrics > maxMetrics {
+			maxAllowedMetrics = maxMetrics
+		}
+	}
+}
+
+var errTooManyMetrics = errors.New("all the tag filters match too many metrics")
+
+func (is *indexSearch) adjustMaxMetricsAdaptive(maxMetrics int) int {
+	hmPrev := is.db.prevHourMetricIDs.Load().(*hourMetricIDs)
+	if !hmPrev.isFull {
+		return maxMetrics
+	}
+	hourMetrics := len(hmPrev.m)
+	if hourMetrics >= 256 && maxMetrics > hourMetrics/4 {
+		// It is cheaper to filter on the hour or day metrics if the minimum
+		// number of matching metrics across tfs exceeds hourMetrics / 4.
+		return hourMetrics / 4
+	}
+	return maxMetrics
+}
+
+func (is *indexSearch) getTagFilterWithMinMetricIDsCount(tfs *TagFilters, maxMetrics int) (*tagFilter, map[uint64]struct{}, error) {
 	var minMetricIDs map[uint64]struct{}
 	var minTf *tagFilter
+	kb := &is.kb
+	uselessTagFilters := 0
 	for i := range tfs.tfs {
 		tf := &tfs.tfs[i]
 		if tf.isNegative {
 			// Skip negative filters.
 			continue
 		}
-		metricIDs, err := is.getMetricIDsMapForTagFilter(tf, maxMetrics)
+
+		kb.B = append(kb.B[:0], uselessSingleTagFilterKeyPrefix)
+		kb.B = encoding.MarshalUint64(kb.B[:0], uint64(maxMetrics))
+		kb.B = tf.Marshal(kb.B)
+		if len(is.db.uselessTagFiltersCache.Get(nil, kb.B)) > 0 {
+			// Skip useless work below, since the tf matches at least maxMetrics metrics.
+			uselessTagFilters++
+			continue
+		}
+
+		metricIDs, err := is.getMetricIDsForTagFilter(tf, maxMetrics)
 		if err != nil {
 			if err == errFallbackToMetricNameMatch {
 				// Skip tag filters requiring to scan for too many metrics.
@@ -1149,25 +1310,37 @@ func (is *indexSearch) getTagFilterWithMinMetricIDsMap(tfs *TagFilters, maxMetri
 			}
 			return nil, nil, fmt.Errorf("cannot find MetricIDs for tagFilter %s: %s", tf, err)
 		}
-		if minTf == nil || len(metricIDs) < len(minMetricIDs) {
-			minMetricIDs = metricIDs
-			minTf = tf
-			maxMetrics = len(minMetricIDs)
-			if maxMetrics <= 1 {
-				// There is no need in inspecting other filters, since minTf
-				// already matches 0 or 1 metric.
-				break
-			}
+		if len(metricIDs) >= maxMetrics {
+			// The tf matches at least maxMetrics. Skip it
+			kb.B = append(kb.B[:0], uselessSingleTagFilterKeyPrefix)
+			kb.B = encoding.MarshalUint64(kb.B[:0], uint64(maxMetrics))
+			kb.B = tf.Marshal(kb.B)
+			is.db.uselessTagFiltersCache.Set(kb.B, uselessTagFilterCacheValue)
+			uselessTagFilters++
+			continue
+		}
+
+		minMetricIDs = metricIDs
+		minTf = tf
+		maxMetrics = len(minMetricIDs)
+		if maxMetrics <= 1 {
+			// There is no need in inspecting other filters, since minTf
+			// already matches 0 or 1 metric.
+			break
 		}
 	}
 	if minTf != nil {
 		return minTf, minMetricIDs, nil
 	}
+	if uselessTagFilters == len(tfs.tfs) {
+		// All the tag filters return at least maxMetrics entries.
+		return nil, nil, errTooManyMetrics
+	}
 
 	// There is no positive filter with small number of matching metrics.
 	// Create it, so it matches all the MetricIDs for tfs.commonPrefix.
 	metricIDs := make(map[uint64]struct{})
-	if err := is.getMetricIDsMapForCommonPrefix(metricIDs, tfs.commonPrefix, maxMetrics); err != nil {
+	if err := is.updateMetricIDsForCommonPrefix(metricIDs, tfs.commonPrefix, maxMetrics); err != nil {
 		return nil, nil, err
 	}
 	return nil, metricIDs, nil
@@ -1236,84 +1409,60 @@ func matchTagFilter(b []byte, tf *tagFilter) (bool, error) {
 }
 
 func (is *indexSearch) searchMetricIDs(tfss []*TagFilters, tr TimeRange, maxMetrics int) ([]uint64, error) {
-	metricIDsMap := make(map[uint64]struct{})
+	metricIDs := make(map[uint64]struct{})
 	for _, tfs := range tfss {
 		if len(tfs.tfs) == 0 {
 			// Return all the metric ids
-			if err := is.getMetricIDsMapForCommonPrefix(metricIDsMap, tfs.commonPrefix, maxMetrics+1); err != nil {
+			if err := is.updateMetricIDsForCommonPrefix(metricIDs, tfs.commonPrefix, maxMetrics+1); err != nil {
 				return nil, err
 			}
-			if len(metricIDsMap) > maxMetrics {
+			if len(metricIDs) > maxMetrics {
 				return nil, fmt.Errorf("the number or unique timeseries exceeds %d; either narrow down the search or increase -search.maxUniqueTimeseries", maxMetrics)
 			}
 			// Stop the iteration, since we cannot find more metric ids with the remaining tfss.
 			break
 		}
-		if err := is.searchMetricIDsMap(metricIDsMap, tfs, tr, maxMetrics+1); err != nil {
+		if err := is.updateMetricIDsForTagFilters(metricIDs, tfs, tr, maxMetrics+1); err != nil {
 			return nil, err
 		}
-		if len(metricIDsMap) > maxMetrics {
+		if len(metricIDs) > maxMetrics {
 			return nil, fmt.Errorf("the number or matching unique timeseries exceeds %d; either narrow down the search or increase -search.maxUniqueTimeseries", maxMetrics)
 		}
 	}
-	if len(metricIDsMap) == 0 {
+	if len(metricIDs) == 0 {
 		// Nothing found
 		return nil, nil
 	}
 
-	metricIDs := getSortedMetricIDs(metricIDsMap)
+	sortedMetricIDs := getSortedMetricIDs(metricIDs)
 
 	// Filter out deleted metricIDs.
 	dmis := is.db.getDeletedMetricIDs()
 	if len(dmis) > 0 {
-		metricIDsFiltered := metricIDs[:0]
-		for _, metricID := range metricIDs {
+		metricIDsFiltered := sortedMetricIDs[:0]
+		for _, metricID := range sortedMetricIDs {
 			if _, deleted := dmis[metricID]; !deleted {
 				metricIDsFiltered = append(metricIDsFiltered, metricID)
 			}
 		}
-		metricIDs = metricIDsFiltered
+		sortedMetricIDs = metricIDsFiltered
 	}
 
-	return metricIDs, nil
+	return sortedMetricIDs, nil
 }
 
-func (is *indexSearch) searchMetricIDsMap(metricIDs map[uint64]struct{}, tfs *TagFilters, tr TimeRange, maxMetrics int) error {
+func (is *indexSearch) updateMetricIDsForTagFilters(metricIDs map[uint64]struct{}, tfs *TagFilters, tr TimeRange, maxMetrics int) error {
 	// Sort tag filters for faster ts.Seek below.
 	sort.Slice(tfs.tfs, func(i, j int) bool { return bytes.Compare(tfs.tfs[i].prefix, tfs.tfs[j].prefix) < 0 })
 
-	// Find the filter with minimum matching metrics.
-	// Iteratively increase maxAllowedMetrics up to maxMetrics in order to limit
-	// the time required for founding the tag filter with minimum matching metrics.
-	var minTf *tagFilter
-	var minMetricIDs map[uint64]struct{}
-	maxAllowedMetrics := 16
-	if maxAllowedMetrics > maxMetrics {
-		maxAllowedMetrics = maxMetrics
-	}
-	for {
-		var err error
-		minTf, minMetricIDs, err = is.getTagFilterWithMinMetricIDsMap(tfs, maxAllowedMetrics)
-		if err != nil {
+	minTf, minMetricIDs, err := is.getTagFilterWithMinMetricIDsCountAdaptive(tfs, maxMetrics)
+	if err != nil {
+		if err != errTooManyMetrics {
 			return err
 		}
-		if len(minMetricIDs) < maxAllowedMetrics {
-			// Found the tag filter with the minimum number of metrics.
-			break
-		}
 
-		// Too many metrics matched.
-		if maxAllowedMetrics < maxMetrics {
-			// Increase maxAllowedMetrics and try again.
-			maxAllowedMetrics *= 4
-			if maxAllowedMetrics > maxMetrics {
-				maxAllowedMetrics = maxMetrics
-			}
-			continue
-		}
+		// All the tag filters match too many metrics.
 
-		// The tag filter with minimum matching metrics matches at least maxMetrics.
-		//
 		// Slow path: try filtering the matching metrics by time range.
 		// This should work well for cases when old metrics are constantly substituted
 		// by big number of new metrics. For example, prometheus-operator creates many new
@@ -1324,11 +1473,8 @@ func (is *indexSearch) searchMetricIDsMap(metricIDs map[uint64]struct{}, tfs *Ta
 		maxTimeRangeMetrics := 20 * maxMetrics
 		metricIDsForTimeRange, err := is.getMetricIDsForTimeRange(tr, maxTimeRangeMetrics+1)
 		if err == errMissingMetricIDsForDate {
-			// Give up.
-			for metricID := range minMetricIDs {
-				metricIDs[metricID] = struct{}{}
-			}
-			return nil
+			return fmt.Errorf("cannot find tag filter matching less than %d time series; either increase -search.maxUniqueTimeseries or use more specific tag filters",
+				maxMetrics)
 		}
 		if err != nil {
 			return err
@@ -1339,7 +1485,6 @@ func (is *indexSearch) searchMetricIDsMap(metricIDs map[uint64]struct{}, tfs *Ta
 		}
 		minMetricIDs = metricIDsForTimeRange
 		minTf = nil
-		break
 	}
 
 	// Find intersection of minTf with other tfs.
@@ -1349,7 +1494,7 @@ func (is *indexSearch) searchMetricIDsMap(metricIDs map[uint64]struct{}, tfs *Ta
 		if tf == minTf {
 			continue
 		}
-		mIDs, err := is.intersectMetricIDsMapForTagFilter(tf, minMetricIDs)
+		mIDs, err := is.intersectMetricIDsWithTagFilter(tf, minMetricIDs)
 		if err == errFallbackToMetricNameMatch {
 			// The tag filter requires too many index scans. Postpone it,
 			// so tag filters with lower number of index scans may be applied.
@@ -1362,9 +1507,9 @@ func (is *indexSearch) searchMetricIDsMap(metricIDs map[uint64]struct{}, tfs *Ta
 		minMetricIDs = mIDs
 	}
 	for i, tf := range tfsPostponed {
-		mIDs, err := is.intersectMetricIDsMapForTagFilter(tf, minMetricIDs)
+		mIDs, err := is.intersectMetricIDsWithTagFilter(tf, minMetricIDs)
 		if err == errFallbackToMetricNameMatch {
-			return is.searchMetricIDsMapByMetricNameMatch(metricIDs, minMetricIDs, tfsPostponed[i:])
+			return is.updateMetricIDsByMetricNameMatch(metricIDs, minMetricIDs, tfsPostponed[i:])
 		}
 		if err != nil {
 			return err
@@ -1377,30 +1522,55 @@ func (is *indexSearch) searchMetricIDsMap(metricIDs map[uint64]struct{}, tfs *Ta
 	return nil
 }
 
-func (is *indexSearch) getMetricIDsMapForTagFilter(tf *tagFilter, maxMetrics int) (map[uint64]struct{}, error) {
+const (
+	uselessSingleTagFilterKeyPrefix = 0
+	uselessMultiTagFiltersKeyPrefix = 1
+)
+
+var uselessTagFilterCacheValue = []byte("1")
+
+func (is *indexSearch) getMetricIDsForTagFilter(tf *tagFilter, maxMetrics int) (map[uint64]struct{}, error) {
 	if tf.isNegative {
 		logger.Panicf("BUG: isNegative must be false")
 	}
 	metricIDs := make(map[uint64]struct{}, maxMetrics)
 	if len(tf.orSuffixes) > 0 {
 		// Fast path for orSuffixes - seek for rows for each value from orSuffxies.
-		if err := is.updateMetricIDsMapForOrSuffixesNoFilter(tf, maxMetrics, metricIDs); err != nil {
+		if err := is.updateMetricIDsForOrSuffixesNoFilter(tf, maxMetrics, metricIDs); err != nil {
 			return nil, err
 		}
 		return metricIDs, nil
 	}
 
-	// Slow path - scan all the rows with tf.prefix
+	// Slow path - scan for all the rows with the given prefix.
 	maxLoops := maxMetrics * maxIndexScanLoopsPerMetric
+	err := is.getMetricIDsForTagFilterSlow(tf, maxLoops, func(metricID uint64) bool {
+		metricIDs[metricID] = struct{}{}
+		return len(metricIDs) < maxMetrics
+	})
+	if err != nil {
+		return nil, err
+	}
+	return metricIDs, nil
+}
+
+func (is *indexSearch) getMetricIDsForTagFilterSlow(tf *tagFilter, maxLoops int, f func(metricID uint64) bool) error {
+	if len(tf.orSuffixes) > 0 {
+		logger.Panicf("BUG: the getMetricIDsForTagFilterSlow must be called only for empty tf.orSuffixes; got %s", tf.orSuffixes)
+	}
+
+	// Scan all the rows with tf.prefix and call f on every tf match.
 	loops := 0
 	ts := &is.ts
+	kb := &is.kb
+	var prevMatchingK []byte
+	var prevMatch bool
 	ts.Seek(tf.prefix)
-	for len(metricIDs) < maxMetrics && ts.NextItem() {
+	for ts.NextItem() {
 		loops++
 		if loops > maxLoops {
-			return nil, errFallbackToMetricNameMatch
+			return errFallbackToMetricNameMatch
 		}
-
 		k := ts.Item
 		if !bytes.HasPrefix(k, tf.prefix) {
 			break
@@ -1409,28 +1579,52 @@ func (is *indexSearch) getMetricIDsMapForTagFilter(tf *tagFilter, maxMetrics int
 		// Get MetricID from k (the last 8 bytes).
 		k = k[len(tf.prefix):]
 		if len(k) < 8 {
-			return nil, fmt.Errorf("invald key suffix size; want at least %d bytes; got %d bytes", 8, len(k))
+			return fmt.Errorf("invald key suffix size; want at least %d bytes; got %d bytes", 8, len(k))
 		}
 		v := k[len(k)-8:]
 		k = k[:len(k)-8]
+		metricID := encoding.UnmarshalUint64(v)
+
+		if prevMatch && string(k) == string(prevMatchingK) {
+			// Fast path: the same tag value found.
+			// There is no need in checking it again with potentially
+			// slow tf.matchSuffix, which may call regexp.
+			if !f(metricID) {
+				break
+			}
+			continue
+		}
 
 		ok, err := tf.matchSuffix(k)
 		if err != nil {
-			return nil, fmt.Errorf("error when matching %s: %s", tf, err)
+			return fmt.Errorf("error when matching %s: %s", tf, err)
 		}
 		if !ok {
+			prevMatch = false
+			// Optimization: skip all the metricIDs for the given tag value
+			kb.B = append(kb.B[:0], ts.Item[:len(ts.Item)-8]...)
+			// The last char in kb.B must be tagSeparatorChar. Just increment it
+			// in order to jump to the next tag value.
+			if len(kb.B) == 0 || kb.B[len(kb.B)-1] != tagSeparatorChar || tagSeparatorChar >= 0xff {
+				return fmt.Errorf("data corruption: the last char in k=%X must be %X", kb.B, tagSeparatorChar)
+			}
+			kb.B[len(kb.B)-1]++
+			ts.Seek(kb.B)
 			continue
 		}
-		metricID := encoding.UnmarshalUint64(v)
-		metricIDs[metricID] = struct{}{}
+		prevMatch = true
+		prevMatchingK = append(prevMatchingK[:0], k...)
+		if !f(metricID) {
+			break
+		}
 	}
 	if err := ts.Error(); err != nil {
-		return nil, fmt.Errorf("error when searching for tag filter prefix %q: %s", tf.prefix, err)
+		return fmt.Errorf("error when searching for tag filter prefix %q: %s", tf.prefix, err)
 	}
-	return metricIDs, nil
+	return nil
 }
 
-func (is *indexSearch) updateMetricIDsMapForOrSuffixesNoFilter(tf *tagFilter, maxMetrics int, metricIDs map[uint64]struct{}) error {
+func (is *indexSearch) updateMetricIDsForOrSuffixesNoFilter(tf *tagFilter, maxMetrics int, metricIDs map[uint64]struct{}) error {
 	if tf.isNegative {
 		logger.Panicf("BUG: isNegative must be false")
 	}
@@ -1440,7 +1634,7 @@ func (is *indexSearch) updateMetricIDsMapForOrSuffixesNoFilter(tf *tagFilter, ma
 		kb.B = append(kb.B[:0], tf.prefix...)
 		kb.B = append(kb.B, orSuffix...)
 		kb.B = append(kb.B, tagSeparatorChar)
-		if err := is.updateMetricIDsMapForOrSuffixNoFilter(kb.B, maxMetrics, metricIDs); err != nil {
+		if err := is.updateMetricIDsForOrSuffixNoFilter(kb.B, maxMetrics, metricIDs); err != nil {
 			return err
 		}
 		if len(metricIDs) >= maxMetrics {
@@ -1450,7 +1644,7 @@ func (is *indexSearch) updateMetricIDsMapForOrSuffixesNoFilter(tf *tagFilter, ma
 	return nil
 }
 
-func (is *indexSearch) updateMetricIDsMapForOrSuffixesWithFilter(tf *tagFilter, metricIDs, filter map[uint64]struct{}) error {
+func (is *indexSearch) updateMetricIDsForOrSuffixesWithFilter(tf *tagFilter, metricIDs, filter map[uint64]struct{}) error {
 	sortedFilter := getSortedMetricIDs(filter)
 	kb := kbPool.Get()
 	defer kbPool.Put(kb)
@@ -1458,14 +1652,14 @@ func (is *indexSearch) updateMetricIDsMapForOrSuffixesWithFilter(tf *tagFilter,
 		kb.B = append(kb.B[:0], tf.prefix...)
 		kb.B = append(kb.B, orSuffix...)
 		kb.B = append(kb.B, tagSeparatorChar)
-		if err := is.updateMetricIDsMapForOrSuffixWithFilter(kb.B, metricIDs, sortedFilter, tf.isNegative); err != nil {
+		if err := is.updateMetricIDsForOrSuffixWithFilter(kb.B, metricIDs, sortedFilter, tf.isNegative); err != nil {
 			return err
 		}
 	}
 	return nil
 }
 
-func (is *indexSearch) updateMetricIDsMapForOrSuffixNoFilter(prefix []byte, maxMetrics int, metricIDs map[uint64]struct{}) error {
+func (is *indexSearch) updateMetricIDsForOrSuffixNoFilter(prefix []byte, maxMetrics int, metricIDs map[uint64]struct{}) error {
 	ts := &is.ts
 	maxLoops := maxMetrics * maxIndexScanLoopsPerMetric
 	loops := 0
@@ -1492,7 +1686,7 @@ func (is *indexSearch) updateMetricIDsMapForOrSuffixNoFilter(prefix []byte, maxM
 	return nil
 }
 
-func (is *indexSearch) updateMetricIDsMapForOrSuffixWithFilter(prefix []byte, metricIDs map[uint64]struct{}, sortedFilter []uint64, isNegative bool) error {
+func (is *indexSearch) updateMetricIDsForOrSuffixWithFilter(prefix []byte, metricIDs map[uint64]struct{}, sortedFilter []uint64, isNegative bool) error {
 	ts := &is.ts
 	kb := &is.kb
 	for {
@@ -1519,6 +1713,15 @@ func (is *indexSearch) updateMetricIDsMapForOrSuffixWithFilter(prefix []byte, me
 		}
 		metricID := encoding.UnmarshalUint64(v)
 		if metricID != nextMetricID {
+			// Skip metricIDs smaller than the found metricID, since they don't
+			// match anything.
+			if len(sortedFilter) > 0 && metricID > sortedFilter[0] {
+				sortedFilter = sortedFilter[1:]
+				n := sort.Search(len(sortedFilter), func(i int) bool {
+					return metricID <= sortedFilter[i]
+				})
+				sortedFilter = sortedFilter[n:]
+			}
 			continue
 		}
 		if isNegative {
@@ -1533,7 +1736,7 @@ func (is *indexSearch) updateMetricIDsMapForOrSuffixWithFilter(prefix []byte, me
 	return nil
 }
 
-var errFallbackToMetricNameMatch = errors.New("fall back to searchMetricIDsMapByMetricNameMatch because of too many index scan loops")
+var errFallbackToMetricNameMatch = errors.New("fall back to updateMetricIDsByMetricNameMatch because of too many index scan loops")
 
 var errMissingMetricIDsForDate = errors.New("missing metricIDs for date")
 
@@ -1541,22 +1744,81 @@ func (is *indexSearch) getMetricIDsForTimeRange(tr TimeRange, maxMetrics int) (m
 	if tr.isZero() {
 		return nil, errMissingMetricIDsForDate
 	}
-	minDate := tr.MinTimestamp / msecPerDay
-	maxDate := tr.MaxTimestamp / msecPerDay
+	atomic.AddUint64(&is.db.recentHourMetricIDsSearchCalls, 1)
+	if metricIDs, ok := is.getMetricIDsForRecentHours(tr, maxMetrics); ok {
+		// Fast path: tr covers the current and / or the previous hour.
+		// Return the full list of metric ids for this time range.
+		atomic.AddUint64(&is.db.recentHourMetricIDsSearchHits, 1)
+		return metricIDs, nil
+	}
+
+	// Slow path: collect the metric ids for all the days covering the given tr.
+	atomic.AddUint64(&is.db.dateMetricIDsSearchCalls, 1)
+	minDate := uint64(tr.MinTimestamp) / msecPerDay
+	maxDate := uint64(tr.MaxTimestamp) / msecPerDay
 	if maxDate-minDate > 40 {
 		// Too much dates must be covered. Give up.
 		return nil, errMissingMetricIDsForDate
 	}
 	metricIDs := make(map[uint64]struct{}, maxMetrics)
 	for minDate <= maxDate {
-		if err := is.getMetricIDsForDate(uint64(minDate), metricIDs, maxMetrics); err != nil {
+		if err := is.getMetricIDsForDate(minDate, metricIDs, maxMetrics); err != nil {
 			return nil, err
 		}
 		minDate++
 	}
+	atomic.AddUint64(&is.db.dateMetricIDsSearchHits, 1)
 	return metricIDs, nil
 }
 
+func (is *indexSearch) getMetricIDsForRecentHours(tr TimeRange, maxMetrics int) (map[uint64]struct{}, bool) {
+	minHour := uint64(tr.MinTimestamp) / msecPerHour
+	maxHour := uint64(tr.MaxTimestamp) / msecPerHour
+	hmCurr := is.db.currHourMetricIDs.Load().(*hourMetricIDs)
+	if maxHour == hmCurr.hour && minHour == maxHour && hmCurr.isFull {
+		// The tr fits the current hour.
+		// Return a copy of hmCurr.m, because the caller may modify
+		// the returned map.
+		if len(hmCurr.m) > maxMetrics {
+			return nil, false
+		}
+		return getMetricIDsCopy(hmCurr.m), true
+	}
+	hmPrev := is.db.prevHourMetricIDs.Load().(*hourMetricIDs)
+	if maxHour == hmPrev.hour && minHour == maxHour && hmPrev.isFull {
+		// The tr fits the previous hour.
+		// Return a copy of hmPrev.m, because the caller may modify
+		// the returned map.
+		if len(hmPrev.m) > maxMetrics {
+			return nil, false
+		}
+		return getMetricIDsCopy(hmPrev.m), true
+	}
+	if maxHour == hmCurr.hour && minHour == hmPrev.hour && hmCurr.isFull && hmPrev.isFull {
+		// The tr spans the previous and the current hours.
+		if len(hmCurr.m)+len(hmPrev.m) > maxMetrics {
+			return nil, false
+		}
+		metricIDs := make(map[uint64]struct{}, len(hmCurr.m)+len(hmPrev.m))
+		for metricID := range hmCurr.m {
+			metricIDs[metricID] = struct{}{}
+		}
+		for metricID := range hmPrev.m {
+			metricIDs[metricID] = struct{}{}
+		}
+		return metricIDs, true
+	}
+	return nil, false
+}
+
+func getMetricIDsCopy(src map[uint64]struct{}) map[uint64]struct{} {
+	dst := make(map[uint64]struct{}, len(src))
+	for metricID := range src {
+		dst[metricID] = struct{}{}
+	}
+	return dst
+}
+
 func (db *indexDB) storeDateMetricID(date, metricID uint64) error {
 	is := db.getIndexSearch()
 	ok, err := is.hasDateMetricID(date, metricID)
@@ -1629,7 +1891,29 @@ func (is *indexSearch) getMetricIDsForDate(date uint64, metricIDs map[uint64]str
 	return nil
 }
 
-func (is *indexSearch) getMetricIDsMapForCommonPrefix(metricIDs map[uint64]struct{}, commonPrefix []byte, maxMetrics int) error {
+func (is *indexSearch) containsTimeRange(tr TimeRange) (bool, error) {
+	ts := &is.ts
+	kb := &is.kb
+
+	// Verify whether the maximum date in `ts` covers tr.MinTimestamp.
+	minDate := uint64(tr.MinTimestamp) / msecPerDay
+	kb.B = marshalCommonPrefix(kb.B[:0], nsPrefixDateToMetricID)
+	kb.B = encoding.MarshalUint64(kb.B, minDate)
+	ts.Seek(kb.B)
+	if !ts.NextItem() {
+		if err := ts.Error(); err != nil {
+			return false, fmt.Errorf("error when searching for minDate=%d, prefix %q: %s", minDate, kb.B, err)
+		}
+		return false, nil
+	}
+	if !bytes.HasPrefix(ts.Item, kb.B[:1]) {
+		// minDate exceeds max date from ts.
+		return false, nil
+	}
+	return true, nil
+}
+
+func (is *indexSearch) updateMetricIDsForCommonPrefix(metricIDs map[uint64]struct{}, commonPrefix []byte, maxMetrics int) error {
 	ts := &is.ts
 	ts.Seek(commonPrefix)
 	for len(metricIDs) < maxMetrics && ts.NextItem() {
@@ -1654,11 +1938,11 @@ func (is *indexSearch) getMetricIDsMapForCommonPrefix(metricIDs map[uint64]struc
 }
 
 // The maximum number of index scan loops per already found metric.
-// Bigger number of loops is slower than searchMetricIDsMapByMetricNameMatch
+// Bigger number of loops is slower than updateMetricIDsByMetricNameMatch
 // over the found metrics.
 const maxIndexScanLoopsPerMetric = 32
 
-func (is *indexSearch) intersectMetricIDsMapForTagFilter(tf *tagFilter, filter map[uint64]struct{}) (map[uint64]struct{}, error) {
+func (is *indexSearch) intersectMetricIDsWithTagFilter(tf *tagFilter, filter map[uint64]struct{}) (map[uint64]struct{}, error) {
 	if len(filter) == 0 {
 		return nil, nil
 	}
@@ -1668,7 +1952,7 @@ func (is *indexSearch) intersectMetricIDsMapForTagFilter(tf *tagFilter, filter m
 	}
 	if len(tf.orSuffixes) > 0 {
 		// Fast path for orSuffixes - seek for rows for each value from orSuffixes.
-		if err := is.updateMetricIDsMapForOrSuffixesWithFilter(tf, metricIDs, filter); err != nil {
+		if err := is.updateMetricIDsForOrSuffixesWithFilter(tf, metricIDs, filter); err != nil {
 			return nil, err
 		}
 		return metricIDs, nil
@@ -1676,47 +1960,19 @@ func (is *indexSearch) intersectMetricIDsMapForTagFilter(tf *tagFilter, filter m
 
 	// Slow path - scan for all the rows with the given prefix.
 	maxLoops := len(filter) * maxIndexScanLoopsPerMetric
-	loops := 0
-	ts := &is.ts
-	ts.Seek(tf.prefix)
-	for ts.NextItem() {
-		loops++
-		if loops > maxLoops {
-			return nil, errFallbackToMetricNameMatch
-		}
-
-		k := ts.Item
-		if !bytes.HasPrefix(k, tf.prefix) {
-			break
-		}
-
-		// Extract MetricID from k (the last 8 bytes).
-		k = k[len(tf.prefix):]
-		if len(k) < 8 {
-			return nil, fmt.Errorf("cannot extract metricID from k; want at least %d bytes; got %d bytes", 8, len(k))
-		}
-		v := k[len(k)-8:]
-		k = k[:len(k)-8]
-
-		ok, err := tf.matchSuffix(k)
-		if err != nil {
-			return nil, fmt.Errorf("error when matching %s: %s", tf, err)
-		}
-		if !ok {
-			continue
-		}
-		metricID := encoding.UnmarshalUint64(v)
+	err := is.getMetricIDsForTagFilterSlow(tf, maxLoops, func(metricID uint64) bool {
 		if tf.isNegative {
 			// filter must be equal to metricIDs
 			delete(metricIDs, metricID)
-			continue
+			return true
 		}
 		if _, ok := filter[metricID]; ok {
 			metricIDs[metricID] = struct{}{}
 		}
-	}
-	if err := ts.Error(); err != nil {
-		return nil, fmt.Errorf("error searching %q: %s", tf.prefix, err)
+		return true
+	})
+	if err != nil {
+		return nil, err
 	}
 	return metricIDs, nil
 }

lib/storage/index_db_test.go

@@ -7,6 +7,7 @@ import (
 	"math/rand"
 	"os"
 	"reflect"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -60,8 +61,14 @@ func TestIndexDBOpenClose(t *testing.T) {
 	metricNameCache := fastcache.New(1234)
 	defer metricIDCache.Reset()
 	defer metricNameCache.Reset()
+
+	var hmCurr atomic.Value
+	hmCurr.Store(&hourMetricIDs{})
+	var hmPrev atomic.Value
+	hmPrev.Store(&hourMetricIDs{})
+
 	for i := 0; i < 5; i++ {
-		db, err := openIndexDB("test-index-db", metricIDCache, metricNameCache)
+		db, err := openIndexDB("test-index-db", metricIDCache, metricNameCache, &hmCurr, &hmPrev)
 		if err != nil {
 			t.Fatalf("cannot open indexDB: %s", err)
 		}
@@ -82,8 +89,14 @@ func TestIndexDB(t *testing.T) {
 		metricNameCache := fastcache.New(1234)
 		defer metricIDCache.Reset()
 		defer metricNameCache.Reset()
+
+		var hmCurr atomic.Value
+		hmCurr.Store(&hourMetricIDs{})
+		var hmPrev atomic.Value
+		hmPrev.Store(&hourMetricIDs{})
+
 		dbName := "test-index-db-serial"
-		db, err := openIndexDB(dbName, metricIDCache, metricNameCache)
+		db, err := openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
 		if err != nil {
 			t.Fatalf("cannot open indexDB: %s", err)
 		}
@@ -113,7 +126,7 @@ func TestIndexDB(t *testing.T) {
 
 		// Re-open the db and verify it works as expected.
 		db.MustClose()
-		db, err = openIndexDB(dbName, metricIDCache, metricNameCache)
+		db, err = openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
 		if err != nil {
 			t.Fatalf("cannot open indexDB: %s", err)
 		}
@@ -133,8 +146,14 @@ func TestIndexDB(t *testing.T) {
 		metricNameCache := fastcache.New(1234)
 		defer metricIDCache.Reset()
 		defer metricNameCache.Reset()
+
+		var hmCurr atomic.Value
+		hmCurr.Store(&hourMetricIDs{})
+		var hmPrev atomic.Value
+		hmPrev.Store(&hourMetricIDs{})
+
 		dbName := "test-index-db-concurrent"
-		db, err := openIndexDB(dbName, metricIDCache, metricNameCache)
+		db, err := openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
 		if err != nil {
 			t.Fatalf("cannot open indexDB: %s", err)
 		}
@@ -293,6 +312,16 @@ func testIndexDBGetOrCreateTSIDByName(db *indexDB, accountsCount, projectsCount,
 }
 
 func testIndexDBCheckTSIDByName(db *indexDB, mns []MetricName, tsids []TSID, isConcurrent bool) error {
+	// fill Date -> MetricID cache
+	date := uint64(timestampFromTime(time.Now())) / msecPerDay
+	for i := range tsids {
+		tsid := &tsids[i]
+		if err := db.storeDateMetricID(date, tsid.MetricID); err != nil {
+			return fmt.Errorf("error in storeDateMetricID(%d, %d): %s", date, tsid.MetricID, err)
+		}
+	}
+	db.tb.DebugFlush()
+
 	hasValue := func(tvs []string, v []byte) bool {
 		for _, tv := range tvs {
 			if string(v) == tv {
@@ -382,6 +411,19 @@ func testIndexDBCheckTSIDByName(db *indexDB, mns []MetricName, tsids []TSID, isC
 		}
 	}
 
+	// Check timerseriesCounters only for serial test.
+	// Concurrent test may create duplicate timeseries, so GetSeriesCount
+	// would return more timeseries than needed.
+	if !isConcurrent {
+		n, err := db.GetSeriesCount()
+		if err != nil {
+			return fmt.Errorf("unexpected error in GetSeriesCount(): %s", err)
+		}
+		if n != uint64(len(timeseriesCounters)) {
+			return fmt.Errorf("unexpected GetSeriesCount(); got %d; want %d", n, uint64(len(timeseriesCounters)))
+		}
+	}
+
 	// Try tag filters.
 	for i := range mns {
 		mn := &mns[i]

lib/storage/index_db_timing_test.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"sync/atomic"
 	"testing"
 
 	"github.com/VictoriaMetrics/fastcache"
@@ -16,8 +17,14 @@ func BenchmarkIndexDBAddTSIDs(b *testing.B) {
 	metricNameCache := fastcache.New(1234)
 	defer metricIDCache.Reset()
 	defer metricNameCache.Reset()
+
+	var hmCurr atomic.Value
+	hmCurr.Store(&hourMetricIDs{})
+	var hmPrev atomic.Value
+	hmPrev.Store(&hourMetricIDs{})
+
 	const dbName = "bench-index-db-add-tsids"
-	db, err := openIndexDB(dbName, metricIDCache, metricNameCache)
+	db, err := openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
 	if err != nil {
 		b.Fatalf("cannot open indexDB: %s", err)
 	}
@@ -76,8 +83,14 @@ func BenchmarkIndexDBSearchTSIDs(b *testing.B) {
 	metricNameCache := fastcache.New(1234)
 	defer metricIDCache.Reset()
 	defer metricNameCache.Reset()
+
+	var hmCurr atomic.Value
+	hmCurr.Store(&hourMetricIDs{})
+	var hmPrev atomic.Value
+	hmPrev.Store(&hourMetricIDs{})
+
 	const dbName = "bench-index-db-search-tsids"
-	db, err := openIndexDB(dbName, metricIDCache, metricNameCache)
+	db, err := openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
 	if err != nil {
 		b.Fatalf("cannot open indexDB: %s", err)
 	}
@@ -88,8 +101,6 @@ func BenchmarkIndexDBSearchTSIDs(b *testing.B) {
 		}
 	}()
 
-	const accountsCount = 111
-	const projectsCount = 33333
 	const recordsCount = 1e5
 
 	// Fill the db with recordsCount records.
@@ -147,8 +158,14 @@ func BenchmarkIndexDBGetTSIDs(b *testing.B) {
 	metricNameCache := fastcache.New(1234)
 	defer metricIDCache.Reset()
 	defer metricNameCache.Reset()
+
+	var hmCurr atomic.Value
+	hmCurr.Store(&hourMetricIDs{})
+	var hmPrev atomic.Value
+	hmPrev.Store(&hourMetricIDs{})
+
 	const dbName = "bench-index-db-get-tsids"
-	db, err := openIndexDB(dbName, metricIDCache, metricNameCache)
+	db, err := openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
 	if err != nil {
 		b.Fatalf("cannot open indexDB: %s", err)
 	}
@@ -160,8 +177,6 @@ func BenchmarkIndexDBGetTSIDs(b *testing.B) {
 	}()
 
 	const recordsPerLoop = 1000
-	const accountsCount = 111
-	const projectsCount = 33333
 	const recordsCount = 1e5
 
 	// Fill the db with recordsCount records.

lib/storage/inmemory_part.go

@@ -51,7 +51,8 @@ func (mp *inmemoryPart) InitFromRows(rows []rawRow) {
 // It is unsafe re-using mp while the returned part is in use.
 func (mp *inmemoryPart) NewPart() (*part, error) {
 	ph := mp.ph
-	return newPart(&ph, "", mp.metaindexData.NewReader(), &mp.timestampsData, &mp.valuesData, &mp.indexData)
+	size := uint64(len(mp.timestampsData.B) + len(mp.valuesData.B) + len(mp.indexData.B) + len(mp.metaindexData.B))
+	return newPart(&ph, "", size, mp.metaindexData.NewReader(), &mp.timestampsData, &mp.valuesData, &mp.indexData)
 }
 
 func getInmemoryPart() *inmemoryPart {

lib/storage/merge.go

@@ -29,7 +29,7 @@ func mergeBlockStreams(ph *partHeader, bsw *blockStreamWriter, bsrs []*blockStre
 	if err == errForciblyStopped {
 		return err
 	}
-	return fmt.Errorf("cannot merge %d streams: %s", len(bsrs), err)
+	return fmt.Errorf("cannot merge %d streams: %s: %s", len(bsrs), bsrs, err)
 }
 
 var bsmPool = &sync.Pool{

lib/storage/metric_name.go

@@ -50,6 +50,12 @@ func (tag *Tag) copyFrom(src *Tag) {
 	tag.Value = append(tag.Value[:0], src.Value...)
 }
 
+func marshalTagValueNoTrailingTagSeparator(dst, src []byte) []byte {
+	dst = marshalTagValue(dst, src)
+	// Remove trailing tagSeparatorChar
+	return dst[:len(dst)-1]
+}
+
 func marshalTagValue(dst, src []byte) []byte {
 	n1 := bytes.IndexByte(src, escapeChar)
 	n2 := bytes.IndexByte(src, tagSeparatorChar)
@@ -586,13 +592,6 @@ func copyTags(dst, src []Tag) []Tag {
 	return dst
 }
 
-func (mn *MetricName) tagsLess(i, j int) bool {
-	a, b := mn.Tags[i].Key, mn.Tags[j].Key
-	a = normalizeTagKey(a)
-	b = normalizeTagKey(b)
-	return bytes.Compare(a, b) < 0
-}
-
 var commonTagKeys = func() map[string][]byte {
 	lcm := map[string][]byte{
 		// job-like tags must go first in MetricName.Tags.

lib/storage/part.go

@@ -36,6 +36,9 @@ type part struct {
 	// Empty for in-memory part.
 	path string
 
+	// Total size in bytes of part data.
+	size uint64
+
 	timestampsFile fs.ReadAtCloser
 	valuesFile     fs.ReadAtCloser
 	indexFile      fs.ReadAtCloser
@@ -59,6 +62,7 @@ func openFilePart(path string) (*part, error) {
 	if err != nil {
 		return nil, fmt.Errorf("cannot open timestamps file: %s", err)
 	}
+	timestampsSize := fs.MustFileSize(timestampsPath)
 
 	valuesPath := path + "/values.bin"
 	valuesFile, err := fs.OpenReaderAt(valuesPath)
@@ -66,6 +70,7 @@ func openFilePart(path string) (*part, error) {
 		timestampsFile.MustClose()
 		return nil, fmt.Errorf("cannot open values file: %s", err)
 	}
+	valuesSize := fs.MustFileSize(valuesPath)
 
 	indexPath := path + "/index.bin"
 	indexFile, err := fs.OpenReaderAt(indexPath)
@@ -74,6 +79,7 @@ func openFilePart(path string) (*part, error) {
 		valuesFile.MustClose()
 		return nil, fmt.Errorf("cannot open index file: %s", err)
 	}
+	indexSize := fs.MustFileSize(indexPath)
 
 	metaindexPath := path + "/metaindex.bin"
 	metaindexFile, err := filestream.Open(metaindexPath, true)
@@ -83,15 +89,17 @@ func openFilePart(path string) (*part, error) {
 		indexFile.MustClose()
 		return nil, fmt.Errorf("cannot open metaindex file: %s", err)
 	}
+	metaindexSize := fs.MustFileSize(metaindexPath)
 
-	return newPart(&ph, path, metaindexFile, timestampsFile, valuesFile, indexFile)
+	size := timestampsSize + valuesSize + indexSize + metaindexSize
+	return newPart(&ph, path, size, metaindexFile, timestampsFile, valuesFile, indexFile)
 }
 
 // newPart returns new part initialized with the given arguments.
 //
 // The returned part calls MustClose on all the files passed to newPart
 // when calling part.MustClose.
-func newPart(ph *partHeader, path string, metaindexReader filestream.ReadCloser, timestampsFile, valuesFile, indexFile fs.ReadAtCloser) (*part, error) {
+func newPart(ph *partHeader, path string, size uint64, metaindexReader filestream.ReadCloser, timestampsFile, valuesFile, indexFile fs.ReadAtCloser) (*part, error) {
 	var errors []error
 	metaindex, err := unmarshalMetaindexRows(nil, metaindexReader)
 	if err != nil {
@@ -102,6 +110,7 @@ func newPart(ph *partHeader, path string, metaindexReader filestream.ReadCloser,
 	p := &part{
 		ph:             *ph,
 		path:           path,
+		size:           size,
 		timestampsFile: timestampsFile,
 		valuesFile:     valuesFile,
 		indexFile:      indexFile,

lib/storage/partition.go

@@ -212,14 +212,8 @@ func createPartition(timestamp int64, smallPartitionsPath, bigPartitionsPath str
 // The pt must be detached from table before calling pt.Drop.
 func (pt *partition) Drop() {
 	logger.Infof("dropping partition %q at smallPartsPath=%q, bigPartsPath=%q", pt.name, pt.smallPartsPath, pt.bigPartsPath)
-
-	if err := os.RemoveAll(pt.smallPartsPath); err != nil {
-		logger.Panicf("FATAL: cannot remove small parts directory %q: %s", pt.smallPartsPath, err)
-	}
-	if err := os.RemoveAll(pt.bigPartsPath); err != nil {
-		logger.Panicf("FATAL: cannot remove big parts directory %q: %s", pt.bigPartsPath, err)
-	}
-
+	fs.MustRemoveAll(pt.smallPartsPath)
+	fs.MustRemoveAll(pt.bigPartsPath)
 	logger.Infof("partition %q has been dropped", pt.name)
 }
 
@@ -288,6 +282,9 @@ type partitionMetrics struct {
 	SmallIndexBlocksCacheRequests uint64
 	SmallIndexBlocksCacheMisses   uint64
 
+	BigSizeBytes   uint64
+	SmallSizeBytes uint64
+
 	BigRowsCount   uint64
 	SmallRowsCount uint64
 
@@ -332,6 +329,7 @@ func (pt *partition) UpdateMetrics(m *partitionMetrics) {
 		m.BigIndexBlocksCacheMisses += p.ibCache.Misses()
 		m.BigRowsCount += p.ph.RowsCount
 		m.BigBlocksCount += p.ph.BlocksCount
+		m.BigSizeBytes += p.size
 		m.BigPartsRefCount += atomic.LoadUint64(&pw.refCount)
 	}
 
@@ -343,6 +341,7 @@ func (pt *partition) UpdateMetrics(m *partitionMetrics) {
 		m.SmallIndexBlocksCacheMisses += p.ibCache.Misses()
 		m.SmallRowsCount += p.ph.RowsCount
 		m.SmallBlocksCount += p.ph.BlocksCount
+		m.SmallSizeBytes += p.size
 		m.SmallPartsRefCount += atomic.LoadUint64(&pw.refCount)
 	}
 
@@ -599,7 +598,7 @@ func (pt *partition) MustClose() {
 	logger.Infof("%d inmemory parts have been flushed to files in %s on %q", len(pws), time.Since(startTime), pt.smallPartsPath)
 
 	// Remove references to smallParts from the pt, so they may be eventually closed
-	// after all the seraches are done.
+	// after all the searches are done.
 	pt.partsLock.Lock()
 	smallParts := pt.smallParts
 	pt.smallParts = nil
@@ -1019,12 +1018,14 @@ func (pt *partition) mergeParts(pws []*partWrapper, stopCh <-chan struct{}) erro
 	}
 
 	var newPW *partWrapper
+	var newPSize uint64
 	if len(dstPartPath) > 0 {
 		// Open the merged part if it is non-empty.
 		newP, err := openFilePart(dstPartPath)
 		if err != nil {
 			return fmt.Errorf("cannot open merged part %q: %s", dstPartPath, err)
 		}
+		newPSize = newP.size
 		newPW = &partWrapper{
 			p:        newP,
 			refCount: 1,
@@ -1063,7 +1064,7 @@ func (pt *partition) mergeParts(pws []*partWrapper, stopCh <-chan struct{}) erro
 
 	d := time.Since(startTime)
 	if d > 10*time.Second {
-		logger.Infof("merged %d rows in %s at %d rows/sec to %q", outRowsCount, d, int(float64(outRowsCount)/d.Seconds()), dstPartPath)
+		logger.Infof("merged %d rows in %s at %d rows/sec to %q; sizeBytes: %d", outRowsCount, d, int(float64(outRowsCount)/d.Seconds()), dstPartPath, newPSize)
 	}
 
 	return nil
@@ -1223,13 +1224,9 @@ func openParts(pathPrefix1, pathPrefix2, path string) ([]*partWrapper, error) {
 	}
 
 	txnDir := path + "/txn"
-	if err := os.RemoveAll(txnDir); err != nil {
-		return nil, fmt.Errorf("cannot delete transaction directory %q: %s", txnDir, err)
-	}
+	fs.MustRemoveAll(txnDir)
 	tmpDir := path + "/tmp"
-	if err := os.RemoveAll(tmpDir); err != nil {
-		return nil, fmt.Errorf("cannot remove temporary directory %q: %s", tmpDir, err)
-	}
+	fs.MustRemoveAll(tmpDir)
 	if err := createPartitionDirs(path); err != nil {
 		return nil, fmt.Errorf("cannot create directories for partition %q: %s", path, err)
 	}
@@ -1342,8 +1339,8 @@ func (pt *partition) createSnapshot(srcDir, dstDir string) error {
 		}
 	}
 
-	fs.SyncPath(dstDir)
-	fs.SyncPath(filepath.Dir(dstDir))
+	fs.MustSyncPath(dstDir)
+	fs.MustSyncPath(filepath.Dir(dstDir))
 
 	return nil
 }
@@ -1408,9 +1405,7 @@ func runTransaction(txnLock *sync.RWMutex, pathPrefix1, pathPrefix2, txnPath str
 		if err != nil {
 			return fmt.Errorf("invalid path to remove: %s", err)
 		}
-		if err := os.RemoveAll(path); err != nil {
-			return fmt.Errorf("cannot remove %q: %s", path, err)
-		}
+		fs.MustRemoveAll(path)
 	}
 
 	// Move the new part to new directory.
@@ -1438,14 +1433,12 @@ func runTransaction(txnLock *sync.RWMutex, pathPrefix1, pathPrefix2, txnPath str
 		}
 	} else {
 		// Just remove srcPath.
-		if err := os.RemoveAll(srcPath); err != nil {
-			return fmt.Errorf("cannot remove %q: %s", srcPath, err)
-		}
+		fs.MustRemoveAll(srcPath)
 	}
 
 	// Flush pathPrefix* directory metadata to the underying storage.
-	fs.SyncPath(pathPrefix1)
-	fs.SyncPath(pathPrefix2)
+	fs.MustSyncPath(pathPrefix1)
+	fs.MustSyncPath(pathPrefix2)
 
 	// Remove the transaction file.
 	if err := os.Remove(txnPath); err != nil {
@@ -1487,6 +1480,6 @@ func createPartitionDirs(path string) error {
 	if err := fs.MkdirAllFailIfExist(tmpPath); err != nil {
 		return fmt.Errorf("cannot create tmp directory %q: %s", tmpPath, err)
 	}
-	fs.SyncPath(path)
+	fs.MustSyncPath(path)
 	return nil
 }

lib/storage/partition_test.go

@@ -112,15 +112,15 @@ func testAppendPartsToMerge(t *testing.T, maxPartsToMerge int, initialRowsCount,
 
 	// Verify appending to prefix
 	prefix := []*partWrapper{
-		&partWrapper{
+		{
 			p: &part{
 				ph: partHeader{
 					RowsCount: 1234,
 				},
 			},
 		},
-		&partWrapper{},
-		&partWrapper{},
+		{},
+		{},
 	}
 	pms = appendPartsToMerge(prefix, pws, maxPartsToMerge, 1e9)
 	if !reflect.DeepEqual(pms[:len(prefix)], prefix) {

lib/storage/raw_row.go

@@ -19,7 +19,7 @@ type rawRow struct {
 	// Value is time series value for the given timestamp.
 	Value float64
 
-	// PrecisionBits is the number of the siginificant bits in the Value
+	// PrecisionBits is the number of the significant bits in the Value
 	// to store. Possible values are [1..64].
 	// 1 means max. 50% error, 2 - 25%, 3 - 12.5%, 64 means no error, i.e.
 	// Value stored without information loss.

lib/storage/search_test.go

@@ -44,7 +44,7 @@ func TestSearchQueryMarshalUnmarshal(t *testing.T) {
 		if sq1.MaxTimestamp != sq2.MaxTimestamp {
 			t.Fatalf("unexpected MaxTimestamp; got %d; want %d", sq2.MaxTimestamp, sq1.MaxTimestamp)
 		}
-		if len(sq1.TagFilterss) != len(sq1.TagFilterss) {
+		if len(sq1.TagFilterss) != len(sq2.TagFilterss) {
 			t.Fatalf("unexpected TagFilterss len; got %d; want %d", len(sq2.TagFilterss), len(sq1.TagFilterss))
 		}
 		for ii := range sq1.TagFilterss {

lib/storage/storage.go

@@ -2,6 +2,7 @@ package storage
 
 import (
 	"fmt"
+	"io/ioutil"
 	"math"
 	"os"
 	"path/filepath"
@@ -18,6 +19,7 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fs"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/memory"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/timerpool"
 	"github.com/VictoriaMetrics/fastcache"
 	"golang.org/x/sys/unix"
 )
@@ -30,7 +32,7 @@ type Storage struct {
 	cachePath       string
 	retentionMonths int
 
-	// lock file for excluse access to the storage on the given path.
+	// lock file for exclusive access to the storage on the given path.
 	flockF *os.File
 
 	idbCurr atomic.Value
@@ -49,8 +51,20 @@ type Storage struct {
 	// dateMetricIDCache is (Date, MetricID) cache.
 	dateMetricIDCache *fastcache.Cache
 
-	stop               chan struct{}
-	retentionWatcherWG sync.WaitGroup
+	// Fast cache for MetricID values occured during the current hour.
+	currHourMetricIDs atomic.Value
+
+	// Fast cache for MetricID values occured during the previous hour.
+	prevHourMetricIDs atomic.Value
+
+	// Pending MetricID values to be added to currHourMetricIDs.
+	pendingHourMetricIDsLock sync.Mutex
+	pendingHourMetricIDs     map[uint64]struct{}
+
+	stop chan struct{}
+
+	currHourMetricIDsUpdaterWG sync.WaitGroup
+	retentionWatcherWG         sync.WaitGroup
 }
 
 // OpenStorage opens storage on the given path with the given number of retention months.
@@ -99,13 +113,20 @@ func OpenStorage(path string, retentionMonths int) (*Storage, error) {
 	s.metricNameCache = s.mustLoadCache("MetricID->MetricName", "metricID_metricName", mem/8)
 	s.dateMetricIDCache = s.mustLoadCache("Date->MetricID", "date_metricID", mem/32)
 
+	hour := uint64(timestampFromTime(time.Now())) / msecPerHour
+	hmCurr := s.mustLoadHourMetricIDs(hour, "curr_hour_metric_ids")
+	hmPrev := s.mustLoadHourMetricIDs(hour-1, "prev_hour_metric_ids")
+	s.currHourMetricIDs.Store(hmCurr)
+	s.prevHourMetricIDs.Store(hmPrev)
+	s.pendingHourMetricIDs = make(map[uint64]struct{})
+
 	// Load indexdb
 	idbPath := path + "/indexdb"
 	idbSnapshotsPath := idbPath + "/snapshots"
 	if err := fs.MkdirAllIfNotExist(idbSnapshotsPath); err != nil {
 		return nil, fmt.Errorf("cannot create %q: %s", idbSnapshotsPath, err)
 	}
-	idbCurr, idbPrev, err := openIndexDBTables(idbPath, s.metricIDCache, s.metricNameCache)
+	idbCurr, idbPrev, err := openIndexDBTables(idbPath, s.metricIDCache, s.metricNameCache, &s.currHourMetricIDs, &s.prevHourMetricIDs)
 	if err != nil {
 		return nil, fmt.Errorf("cannot open indexdb tables at %q: %s", idbPath, err)
 	}
@@ -121,6 +142,7 @@ func OpenStorage(path string, retentionMonths int) (*Storage, error) {
 	}
 	s.tb = tb
 
+	s.startCurrHourMetricIDsUpdater()
 	s.startRetentionWatcher()
 
 	return s, nil
@@ -164,7 +186,7 @@ func (s *Storage) CreateSnapshot() (string, error) {
 	if err := fs.SymlinkRelative(bigDir, dstBigDir); err != nil {
 		return "", fmt.Errorf("cannot create symlink from %q to %q: %s", bigDir, dstBigDir, err)
 	}
-	fs.SyncPath(dstDataDir)
+	fs.MustSyncPath(dstDataDir)
 
 	idbSnapshot := fmt.Sprintf("%s/indexdb/snapshots/%s", s.path, snapshotName)
 	idb := s.idb()
@@ -184,8 +206,8 @@ func (s *Storage) CreateSnapshot() (string, error) {
 		return "", fmt.Errorf("cannot create symlink from %q to %q: %s", idbSnapshot, dstIdbDir, err)
 	}
 
-	fs.SyncPath(dstDir)
-	fs.SyncPath(srcDir + "/snapshots")
+	fs.MustSyncPath(dstDir)
+	fs.MustSyncPath(srcDir + "/snapshots")
 
 	logger.Infof("created Storage snapshot for %q at %q in %s", srcDir, dstDir, time.Since(startTime))
 	return snapshotName, nil
@@ -229,8 +251,8 @@ func (s *Storage) DeleteSnapshot(snapshotName string) error {
 
 	s.tb.MustDeleteSnapshot(snapshotName)
 	idbPath := fmt.Sprintf("%s/indexdb/snapshots/%s", s.path, snapshotName)
-	fs.MustRemoveAllSynced(idbPath)
-	fs.MustRemoveAllSynced(snapshotPath)
+	fs.MustRemoveAll(idbPath)
+	fs.MustRemoveAll(snapshotPath)
 
 	logger.Infof("deleted snapshot %q in %s", snapshotPath, time.Since(startTime))
 
@@ -250,29 +272,31 @@ func (s *Storage) idb() *indexDB {
 // Metrics contains essential metrics for the Storage.
 type Metrics struct {
 	TSIDCacheSize       uint64
-	TSIDCacheBytesSize  uint64
+	TSIDCacheSizeBytes  uint64
 	TSIDCacheRequests   uint64
 	TSIDCacheMisses     uint64
 	TSIDCacheCollisions uint64
 
 	MetricIDCacheSize       uint64
-	MetricIDCacheBytesSize  uint64
+	MetricIDCacheSizeBytes  uint64
 	MetricIDCacheRequests   uint64
 	MetricIDCacheMisses     uint64
 	MetricIDCacheCollisions uint64
 
 	MetricNameCacheSize       uint64
-	MetricNameCacheBytesSize  uint64
+	MetricNameCacheSizeBytes  uint64
 	MetricNameCacheRequests   uint64
 	MetricNameCacheMisses     uint64
 	MetricNameCacheCollisions uint64
 
 	DateMetricIDCacheSize       uint64
-	DateMetricIDCacheBytesSize  uint64
+	DateMetricIDCacheSizeBytes  uint64
 	DateMetricIDCacheRequests   uint64
 	DateMetricIDCacheMisses     uint64
 	DateMetricIDCacheCollisions uint64
 
+	HourMetricIDCacheSize uint64
+
 	IndexDBMetrics IndexDBMetrics
 	TableMetrics   TableMetrics
 }
@@ -287,7 +311,7 @@ func (s *Storage) UpdateMetrics(m *Metrics) {
 	var cs fastcache.Stats
 	s.tsidCache.UpdateStats(&cs)
 	m.TSIDCacheSize += cs.EntriesCount
-	m.TSIDCacheBytesSize += cs.BytesSize
+	m.TSIDCacheSizeBytes += cs.BytesSize
 	m.TSIDCacheRequests += cs.GetCalls
 	m.TSIDCacheMisses += cs.Misses
 	m.TSIDCacheCollisions += cs.Collisions
@@ -295,7 +319,7 @@ func (s *Storage) UpdateMetrics(m *Metrics) {
 	cs.Reset()
 	s.metricIDCache.UpdateStats(&cs)
 	m.MetricIDCacheSize += cs.EntriesCount
-	m.MetricIDCacheBytesSize += cs.BytesSize
+	m.MetricIDCacheSizeBytes += cs.BytesSize
 	m.MetricIDCacheRequests += cs.GetCalls
 	m.MetricIDCacheMisses += cs.Misses
 	m.MetricIDCacheCollisions += cs.Collisions
@@ -303,7 +327,7 @@ func (s *Storage) UpdateMetrics(m *Metrics) {
 	cs.Reset()
 	s.metricNameCache.UpdateStats(&cs)
 	m.MetricNameCacheSize += cs.EntriesCount
-	m.MetricNameCacheBytesSize += cs.BytesSize
+	m.MetricNameCacheSizeBytes += cs.BytesSize
 	m.MetricNameCacheRequests += cs.GetCalls
 	m.MetricNameCacheMisses += cs.Misses
 	m.MetricNameCacheCollisions += cs.Collisions
@@ -311,11 +335,19 @@ func (s *Storage) UpdateMetrics(m *Metrics) {
 	cs.Reset()
 	s.dateMetricIDCache.UpdateStats(&cs)
 	m.DateMetricIDCacheSize += cs.EntriesCount
-	m.DateMetricIDCacheBytesSize += cs.BytesSize
+	m.DateMetricIDCacheSizeBytes += cs.BytesSize
 	m.DateMetricIDCacheRequests += cs.GetCalls
 	m.DateMetricIDCacheMisses += cs.Misses
 	m.DateMetricIDCacheCollisions += cs.Collisions
 
+	hmCurr := s.currHourMetricIDs.Load().(*hourMetricIDs)
+	hmPrev := s.prevHourMetricIDs.Load().(*hourMetricIDs)
+	hourMetricIDsLen := len(hmPrev.m)
+	if len(hmCurr.m) > hourMetricIDsLen {
+		hourMetricIDsLen = len(hmCurr.m)
+	}
+	m.HourMetricIDCacheSize += uint64(hourMetricIDsLen)
+
 	s.idb().UpdateMetrics(&m.IndexDBMetrics)
 	s.tb.UpdateMetrics(&m.TableMetrics)
 }
@@ -340,11 +372,34 @@ func (s *Storage) retentionWatcher() {
 	}
 }
 
+func (s *Storage) startCurrHourMetricIDsUpdater() {
+	s.currHourMetricIDsUpdaterWG.Add(1)
+	go func() {
+		s.currHourMetricIDsUpdater()
+		s.currHourMetricIDsUpdaterWG.Done()
+	}()
+}
+
+var currHourMetricIDsUpdateInterval = time.Second * 10
+
+func (s *Storage) currHourMetricIDsUpdater() {
+	t := time.NewTimer(currHourMetricIDsUpdateInterval)
+	for {
+		select {
+		case <-s.stop:
+			return
+		case <-t.C:
+			s.updateCurrHourMetricIDs()
+			t.Reset(currHourMetricIDsUpdateInterval)
+		}
+	}
+}
+
 func (s *Storage) mustRotateIndexDB() {
 	// Create new indexdb table.
 	newTableName := nextIndexDBTableName()
 	idbNewPath := s.path + "/indexdb/" + newTableName
-	idbNew, err := openIndexDB(idbNewPath, s.metricIDCache, s.metricNameCache)
+	idbNew, err := openIndexDB(idbNewPath, s.metricIDCache, s.metricNameCache, &s.currHourMetricIDs, &s.prevHourMetricIDs)
 	if err != nil {
 		logger.Panicf("FATAL: cannot create new indexDB at %q: %s", idbNewPath, err)
 	}
@@ -361,7 +416,7 @@ func (s *Storage) mustRotateIndexDB() {
 	s.idbCurr.Store(idbNew)
 
 	// Persist changes on the file system.
-	fs.SyncPath(s.path)
+	fs.MustSyncPath(s.path)
 
 	// Flush tsidCache, so idbNew can be populated with fresh data.
 	s.tsidCache.Reset()
@@ -378,6 +433,7 @@ func (s *Storage) MustClose() {
 	close(s.stop)
 
 	s.retentionWatcherWG.Wait()
+	s.currHourMetricIDsUpdaterWG.Wait()
 
 	s.tb.MustClose()
 	s.idb().MustClose()
@@ -388,20 +444,91 @@ func (s *Storage) MustClose() {
 	s.mustSaveCache(s.metricNameCache, "MetricID->MetricName", "metricID_metricName")
 	s.mustSaveCache(s.dateMetricIDCache, "Date->MetricID", "date_metricID")
 
+	hmCurr := s.currHourMetricIDs.Load().(*hourMetricIDs)
+	s.mustSaveHourMetricIDs(hmCurr, "curr_hour_metric_ids")
+	hmPrev := s.prevHourMetricIDs.Load().(*hourMetricIDs)
+	s.mustSaveHourMetricIDs(hmPrev, "prev_hour_metric_ids")
+
 	// Release lock file.
 	if err := s.flockF.Close(); err != nil {
 		logger.Panicf("FATAL: cannot close lock file %q: %s", s.flockF.Name(), err)
 	}
 }
 
-func (s *Storage) mustLoadCache(info, name string, bytesSize int) *fastcache.Cache {
+func (s *Storage) mustLoadHourMetricIDs(hour uint64, name string) *hourMetricIDs {
+	path := s.cachePath + "/" + name
+	logger.Infof("loading %s from %q...", name, path)
+	startTime := time.Now()
+	if !fs.IsPathExist(path) {
+		logger.Infof("nothing to load from %q", path)
+		return &hourMetricIDs{}
+	}
+	src, err := ioutil.ReadFile(path)
+	if err != nil {
+		logger.Panicf("FATAL: cannot read %s: %s", path, err)
+	}
+	srcOrigLen := len(src)
+	if len(src) < 24 {
+		logger.Errorf("discarding %s, since it has broken header; got %d bytes; want %d bytes", path, len(src), 24)
+		return &hourMetricIDs{}
+	}
+	isFull := encoding.UnmarshalUint64(src)
+	src = src[8:]
+	hourLoaded := encoding.UnmarshalUint64(src)
+	src = src[8:]
+	if hourLoaded != hour {
+		logger.Infof("discarding %s, since it is outdated", name)
+		return &hourMetricIDs{}
+	}
+	hmLen := encoding.UnmarshalUint64(src)
+	src = src[8:]
+	if uint64(len(src)) != 8*hmLen {
+		logger.Errorf("discarding %s, since it has broken body; got %d bytes; want %d bytes", path, len(src), 8*hmLen)
+		return &hourMetricIDs{}
+	}
+	m := make(map[uint64]struct{}, hmLen)
+	for i := uint64(0); i < hmLen; i++ {
+		metricID := encoding.UnmarshalUint64(src)
+		src = src[8:]
+		m[metricID] = struct{}{}
+	}
+	logger.Infof("loaded %s from %q in %s; entriesCount: %d; sizeBytes: %d", name, path, time.Since(startTime), hmLen, srcOrigLen)
+	return &hourMetricIDs{
+		m:      m,
+		hour:   hourLoaded,
+		isFull: isFull != 0,
+	}
+}
+
+func (s *Storage) mustSaveHourMetricIDs(hm *hourMetricIDs, name string) {
+	path := s.cachePath + "/" + name
+	logger.Infof("saving %s to %q...", name, path)
+	startTime := time.Now()
+	dst := make([]byte, 0, len(hm.m)*8+24)
+	isFull := uint64(0)
+	if hm.isFull {
+		isFull = 1
+	}
+	dst = encoding.MarshalUint64(dst, isFull)
+	dst = encoding.MarshalUint64(dst, hm.hour)
+	dst = encoding.MarshalUint64(dst, uint64(len(hm.m)))
+	for metricID := range hm.m {
+		dst = encoding.MarshalUint64(dst, metricID)
+	}
+	if err := ioutil.WriteFile(path, dst, 0644); err != nil {
+		logger.Panicf("FATAL: cannot write %d bytes to %q: %s", len(dst), path, err)
+	}
+	logger.Infof("saved %s to %q in %s; entriesCount: %d; sizeBytes: %d", name, path, time.Since(startTime), len(hm.m), len(dst))
+}
+
+func (s *Storage) mustLoadCache(info, name string, sizeBytes int) *fastcache.Cache {
 	path := s.cachePath + "/" + name
 	logger.Infof("loading %s cache from %q...", info, path)
 	startTime := time.Now()
-	c := fastcache.LoadFromFileOrNew(path, bytesSize)
+	c := fastcache.LoadFromFileOrNew(path, sizeBytes)
 	var cs fastcache.Stats
 	c.UpdateStats(&cs)
-	logger.Infof("loaded %s cache from %q in %s; entriesCount: %d; bytesSize: %d",
+	logger.Infof("loaded %s cache from %q in %s; entriesCount: %d; sizeBytes: %d",
 		info, path, time.Since(startTime), cs.EntriesCount, cs.BytesSize)
 	return c
 }
@@ -417,7 +544,7 @@ func (s *Storage) mustSaveCache(c *fastcache.Cache, info, name string) {
 	var cs fastcache.Stats
 	c.UpdateStats(&cs)
 	c.Reset()
-	logger.Infof("saved %s cache to %q in %s; entriesCount: %d; bytesSize: %d",
+	logger.Infof("saved %s cache to %q in %s; entriesCount: %d; sizeBytes: %d",
 		info, path, time.Since(startTime), cs.EntriesCount, cs.BytesSize)
 }
 
@@ -475,6 +602,39 @@ func (s *Storage) SearchTagValues(tagKey []byte, maxTagValues int) ([]string, er
 	return s.idb().SearchTagValues(tagKey, maxTagValues)
 }
 
+// SearchTagEntries returns a list of (tagName -> tagValues) for (accountID, projectID).
+func (s *Storage) SearchTagEntries(maxTagKeys, maxTagValues int) ([]TagEntry, error) {
+	idb := s.idb()
+	keys, err := idb.SearchTagKeys(maxTagKeys)
+	if err != nil {
+		return nil, fmt.Errorf("cannot search tag keys: %s", err)
+	}
+
+	// Sort keys for faster seeks below
+	sort.Strings(keys)
+
+	tes := make([]TagEntry, len(keys))
+	for i, key := range keys {
+		values, err := idb.SearchTagValues([]byte(key), maxTagValues)
+		if err != nil {
+			return nil, fmt.Errorf("cannot search values for tag %q: %s", key, err)
+		}
+		te := &tes[i]
+		te.Key = key
+		te.Values = values
+	}
+	return tes, nil
+}
+
+// TagEntry contains (tagName -> tagValues) mapping
+type TagEntry struct {
+	// Key is tagName
+	Key string
+
+	// Values contains all the values for Key.
+	Values []string
+}
+
 // GetSeriesCount returns the approximate number of unique time series.
 //
 // It includes the deleted series too and may count the same series
@@ -553,12 +713,13 @@ func (s *Storage) AddRows(mrs []MetricRow, precisionBits uint8) error {
 	// Limit the number of concurrent goroutines that may add rows to the storage.
 	// This should prevent from out of memory errors and CPU trashing when too many
 	// goroutines call AddRows.
-	t := time.NewTimer(addRowsTimeout)
+	t := timerpool.Get(addRowsTimeout)
 	select {
 	case addRowsConcurrencyCh <- struct{}{}:
-		t.Stop()
+		timerpool.Put(t)
 		defer func() { <-addRowsConcurrencyCh }()
 	case <-t.C:
+		timerpool.Put(t)
 		return fmt.Errorf("Cannot add %d rows to storage in %s, since it is overloaded with %d concurrent writers. Add more CPUs or reduce load",
 			len(mrs), addRowsTimeout, cap(addRowsConcurrencyCh))
 	}
@@ -591,6 +752,7 @@ func (s *Storage) add(rows []rawRow, mrs []MetricRow, precisionBits uint8) ([]ra
 	}
 	rows = rows[:rowsLen+len(mrs)]
 	j := 0
+	minTimestamp, maxTimestamp := s.tb.getMinMaxTimestamps()
 	for i := range mrs {
 		mr := &mrs[i]
 		if math.IsNaN(mr.Value) {
@@ -598,6 +760,10 @@ func (s *Storage) add(rows []rawRow, mrs []MetricRow, precisionBits uint8) ([]ra
 			// doesn't know how to work with them.
 			continue
 		}
+		if mr.Timestamp < minTimestamp || mr.Timestamp > maxTimestamp {
+			// Skip rows with timestamps outside the retention.
+			continue
+		}
 		r := &rows[rowsLen+j]
 		j++
 		r.Timestamp = mr.Timestamp
@@ -656,13 +822,14 @@ func (s *Storage) add(rows []rawRow, mrs []MetricRow, precisionBits uint8) ([]ra
 	errors = s.updateDateMetricIDCache(rows, errors)
 	if len(errors) > 0 {
 		// Return only the first error, since it has no sense in returning all errors.
-		return rows, fmt.Errorf("errors occured during rows addition: %s", errors[0])
+		return rows, fmt.Errorf("errors occurred during rows addition: %s", errors[0])
 	}
 	return rows, nil
 }
 
 func (s *Storage) updateDateMetricIDCache(rows []rawRow, errors []error) []error {
 	var date uint64
+	var hour uint64
 	var prevTimestamp int64
 	kb := kbPool.Get()
 	defer kbPool.Put(kb)
@@ -674,17 +841,30 @@ func (s *Storage) updateDateMetricIDCache(rows []rawRow, errors []error) []error
 		r := &rows[i]
 		if r.Timestamp != prevTimestamp {
 			date = uint64(r.Timestamp) / msecPerDay
+			hour = uint64(r.Timestamp) / msecPerHour
 			prevTimestamp = r.Timestamp
 		}
 		metricID := r.TSID.MetricID
+		hm := s.currHourMetricIDs.Load().(*hourMetricIDs)
+		if hour == hm.hour {
+			// The r belongs to the current hour. Check for the current hour cache.
+			if _, ok := hm.m[metricID]; ok {
+				// Fast path: the metricID is in the current hour cache.
+				continue
+			}
+			s.pendingHourMetricIDsLock.Lock()
+			s.pendingHourMetricIDs[metricID] = struct{}{}
+			s.pendingHourMetricIDsLock.Unlock()
+		}
+
+		// Slower path: check global cache for (date, metricID) entry.
 		a[0] = date
 		a[1] = metricID
 		if s.dateMetricIDCache.Has(keyBuf) {
-			// Fast path: the (date, metricID) entry is in the cache.
 			continue
 		}
 
-		// Slow path: store the entry in the cache and in the indexDB.
+		// Slow path: store the entry in the (date, metricID) cache and in the indexDB.
 		// It is OK if the (date, metricID) entry is added multiple times to db
 		// by concurrent goroutines.
 		s.dateMetricIDCache.Set(keyBuf, nil)
@@ -696,6 +876,54 @@ func (s *Storage) updateDateMetricIDCache(rows []rawRow, errors []error) []error
 	return errors
 }
 
+func (s *Storage) updateCurrHourMetricIDs() {
+	hm := s.currHourMetricIDs.Load().(*hourMetricIDs)
+	s.pendingHourMetricIDsLock.Lock()
+	newMetricIDsLen := len(s.pendingHourMetricIDs)
+	s.pendingHourMetricIDsLock.Unlock()
+	hour := uint64(timestampFromTime(time.Now())) / msecPerHour
+	if newMetricIDsLen == 0 && hm.hour == hour {
+		// Fast path: nothing to update.
+		return
+	}
+
+	// Slow path: hm.m must be updated with non-empty s.pendingHourMetricIDs.
+	var m map[uint64]struct{}
+	isFull := hm.isFull
+	if hm.hour == hour {
+		m = make(map[uint64]struct{}, len(hm.m)+newMetricIDsLen)
+		for metricID := range hm.m {
+			m[metricID] = struct{}{}
+		}
+	} else {
+		m = make(map[uint64]struct{}, newMetricIDsLen)
+		isFull = true
+	}
+	s.pendingHourMetricIDsLock.Lock()
+	newMetricIDs := s.pendingHourMetricIDs
+	s.pendingHourMetricIDs = make(map[uint64]struct{}, len(newMetricIDs))
+	s.pendingHourMetricIDsLock.Unlock()
+	for metricID := range newMetricIDs {
+		m[metricID] = struct{}{}
+	}
+
+	hmNew := &hourMetricIDs{
+		m:      m,
+		hour:   hour,
+		isFull: isFull,
+	}
+	s.currHourMetricIDs.Store(hmNew)
+	if hm.hour != hour {
+		s.prevHourMetricIDs.Store(hm)
+	}
+}
+
+type hourMetricIDs struct {
+	m      map[uint64]struct{}
+	hour   uint64
+	isFull bool
+}
+
 func (s *Storage) getTSIDFromCache(dst *TSID, metricName []byte) bool {
 	buf := (*[unsafe.Sizeof(*dst)]byte)(unsafe.Pointer(dst))[:]
 	buf = s.tsidCache.Get(buf[:0], metricName)
@@ -707,7 +935,7 @@ func (s *Storage) putTSIDToCache(tsid *TSID, metricName []byte) {
 	s.tsidCache.Set(metricName, buf)
 }
 
-func openIndexDBTables(path string, metricIDCache, metricNameCache *fastcache.Cache) (curr, prev *indexDB, err error) {
+func openIndexDBTables(path string, metricIDCache, metricNameCache *fastcache.Cache, currHourMetricIDs, prevHourMetricIDs *atomic.Value) (curr, prev *indexDB, err error) {
 	if err := fs.MkdirAllIfNotExist(path); err != nil {
 		return nil, nil, fmt.Errorf("cannot create directory %q: %s", path, err)
 	}
@@ -756,24 +984,22 @@ func openIndexDBTables(path string, metricIDCache, metricNameCache *fastcache.Ca
 	for _, tn := range tableNames[:len(tableNames)-2] {
 		pathToRemove := path + "/" + tn
 		logger.Infof("removing obsolete indexdb dir %q...", pathToRemove)
-		if err := os.RemoveAll(pathToRemove); err != nil {
-			return nil, nil, fmt.Errorf("cannot remove obsolete indexdb dir %q: %s", pathToRemove, err)
-		}
+		fs.MustRemoveAll(pathToRemove)
 		logger.Infof("removed obsolete indexdb dir %q", pathToRemove)
 	}
 
 	// Persist changes on the file system.
-	fs.SyncPath(path)
+	fs.MustSyncPath(path)
 
 	// Open the last two tables.
 	currPath := path + "/" + tableNames[len(tableNames)-1]
 
-	curr, err = openIndexDB(currPath, metricIDCache, metricNameCache)
+	curr, err = openIndexDB(currPath, metricIDCache, metricNameCache, currHourMetricIDs, prevHourMetricIDs)
 	if err != nil {
 		return nil, nil, fmt.Errorf("cannot open curr indexdb table at %q: %s", currPath, err)
 	}
 	prevPath := path + "/" + tableNames[len(tableNames)-2]
-	prev, err = openIndexDB(prevPath, metricIDCache, metricNameCache)
+	prev, err = openIndexDB(prevPath, metricIDCache, metricNameCache, currHourMetricIDs, prevHourMetricIDs)
 	if err != nil {
 		curr.MustClose()
 		return nil, nil, fmt.Errorf("cannot open prev indexdb table at %q: %s", prevPath, err)

lib/storage/storage_test.go

@@ -11,6 +11,184 @@ import (
 	"time"
 )
 
+func TestUpdateCurrHourMetricIDs(t *testing.T) {
+	newStorage := func() *Storage {
+		var s Storage
+		s.currHourMetricIDs.Store(&hourMetricIDs{})
+		s.prevHourMetricIDs.Store(&hourMetricIDs{})
+		s.pendingHourMetricIDs = make(map[uint64]struct{})
+		return &s
+	}
+	t.Run("empty_pedning_metric_ids_stale_curr_hour", func(t *testing.T) {
+		s := newStorage()
+		hour := uint64(timestampFromTime(time.Now())) / msecPerHour
+		hmOrig := &hourMetricIDs{
+			m: map[uint64]struct{}{
+				12: {},
+				34: {},
+			},
+			hour: 123,
+		}
+		s.currHourMetricIDs.Store(hmOrig)
+		s.updateCurrHourMetricIDs()
+		hmCurr := s.currHourMetricIDs.Load().(*hourMetricIDs)
+		if hmCurr.hour != hour {
+			// It is possible new hour occured. Update the hour and verify it again.
+			hour = uint64(timestampFromTime(time.Now())) / msecPerHour
+			if hmCurr.hour != hour {
+				t.Fatalf("unexpected hmCurr.hour; got %d; want %d", hmCurr.hour, hour)
+			}
+		}
+		if len(hmCurr.m) != 0 {
+			t.Fatalf("unexpected length of hm.m; got %d; want %d", len(hmCurr.m), 0)
+		}
+		if !hmCurr.isFull {
+			t.Fatalf("unexpected hmCurr.isFull; got %v; want %v", hmCurr.isFull, true)
+		}
+
+		hmPrev := s.prevHourMetricIDs.Load().(*hourMetricIDs)
+		if !reflect.DeepEqual(hmPrev, hmOrig) {
+			t.Fatalf("unexpected hmPrev; got %v; want %v", hmPrev, hmOrig)
+		}
+
+		if len(s.pendingHourMetricIDs) != 0 {
+			t.Fatalf("unexpected len(s.pendingHourMetricIDs); got %d; want %d", len(s.pendingHourMetricIDs), 0)
+		}
+	})
+	t.Run("empty_pedning_metric_ids_valid_curr_hour", func(t *testing.T) {
+		s := newStorage()
+		hour := uint64(timestampFromTime(time.Now())) / msecPerHour
+		hmOrig := &hourMetricIDs{
+			m: map[uint64]struct{}{
+				12: {},
+				34: {},
+			},
+			hour: hour,
+		}
+		s.currHourMetricIDs.Store(hmOrig)
+		s.updateCurrHourMetricIDs()
+		hmCurr := s.currHourMetricIDs.Load().(*hourMetricIDs)
+		if hmCurr.hour != hour {
+			// It is possible new hour occured. Update the hour and verify it again.
+			hour = uint64(timestampFromTime(time.Now())) / msecPerHour
+			if hmCurr.hour != hour {
+				t.Fatalf("unexpected hmCurr.hour; got %d; want %d", hmCurr.hour, hour)
+			}
+			// Do not run other checks, since they may fail.
+			return
+		}
+		if !reflect.DeepEqual(hmCurr, hmOrig) {
+			t.Fatalf("unexpected hmCurr; got %v; want %v", hmCurr, hmOrig)
+		}
+		if hmCurr.isFull {
+			t.Fatalf("unexpected hmCurr.isFull; got %v; want %v", hmCurr.isFull, false)
+		}
+
+		hmPrev := s.prevHourMetricIDs.Load().(*hourMetricIDs)
+		hmEmpty := &hourMetricIDs{}
+		if !reflect.DeepEqual(hmPrev, hmEmpty) {
+			t.Fatalf("unexpected hmPrev; got %v; want %v", hmPrev, hmEmpty)
+		}
+
+		if len(s.pendingHourMetricIDs) != 0 {
+			t.Fatalf("unexpected len(s.pendingHourMetricIDs); got %d; want %d", len(s.pendingHourMetricIDs), 0)
+		}
+	})
+	t.Run("nonempty_pending_metric_ids_stale_curr_hour", func(t *testing.T) {
+		s := newStorage()
+		pendingHourMetricIDs := map[uint64]struct{}{
+			343:     {},
+			32424:   {},
+			8293432: {},
+		}
+		s.pendingHourMetricIDs = pendingHourMetricIDs
+
+		hour := uint64(timestampFromTime(time.Now())) / msecPerHour
+		hmOrig := &hourMetricIDs{
+			m: map[uint64]struct{}{
+				12: {},
+				34: {},
+			},
+			hour: 123,
+		}
+		s.currHourMetricIDs.Store(hmOrig)
+		s.updateCurrHourMetricIDs()
+		hmCurr := s.currHourMetricIDs.Load().(*hourMetricIDs)
+		if hmCurr.hour != hour {
+			// It is possible new hour occured. Update the hour and verify it again.
+			hour = uint64(timestampFromTime(time.Now())) / msecPerHour
+			if hmCurr.hour != hour {
+				t.Fatalf("unexpected hmCurr.hour; got %d; want %d", hmCurr.hour, hour)
+			}
+		}
+		if !reflect.DeepEqual(hmCurr.m, pendingHourMetricIDs) {
+			t.Fatalf("unexpected hm.m; got %v; want %v", hmCurr.m, pendingHourMetricIDs)
+		}
+		if !hmCurr.isFull {
+			t.Fatalf("unexpected hmCurr.isFull; got %v; want %v", hmCurr.isFull, true)
+		}
+
+		hmPrev := s.prevHourMetricIDs.Load().(*hourMetricIDs)
+		if !reflect.DeepEqual(hmPrev, hmOrig) {
+			t.Fatalf("unexpected hmPrev; got %v; want %v", hmPrev, hmOrig)
+		}
+
+		if len(s.pendingHourMetricIDs) != 0 {
+			t.Fatalf("unexpected len(s.pendingHourMetricIDs); got %d; want %d", len(s.pendingHourMetricIDs), 0)
+		}
+	})
+	t.Run("nonempty_pending_metric_ids_valid_curr_hour", func(t *testing.T) {
+		s := newStorage()
+		pendingHourMetricIDs := map[uint64]struct{}{
+			343:     {},
+			32424:   {},
+			8293432: {},
+		}
+		s.pendingHourMetricIDs = pendingHourMetricIDs
+
+		hour := uint64(timestampFromTime(time.Now())) / msecPerHour
+		hmOrig := &hourMetricIDs{
+			m: map[uint64]struct{}{
+				12: {},
+				34: {},
+			},
+			hour: hour,
+		}
+		s.currHourMetricIDs.Store(hmOrig)
+		s.updateCurrHourMetricIDs()
+		hmCurr := s.currHourMetricIDs.Load().(*hourMetricIDs)
+		if hmCurr.hour != hour {
+			// It is possible new hour occured. Update the hour and verify it again.
+			hour = uint64(timestampFromTime(time.Now())) / msecPerHour
+			if hmCurr.hour != hour {
+				t.Fatalf("unexpected hmCurr.hour; got %d; want %d", hmCurr.hour, hour)
+			}
+			// Do not run other checks, since they may fail.
+			return
+		}
+		m := getMetricIDsCopy(pendingHourMetricIDs)
+		for metricID := range hmOrig.m {
+			m[metricID] = struct{}{}
+		}
+		if !reflect.DeepEqual(hmCurr.m, m) {
+			t.Fatalf("unexpected hm.m; got %v; want %v", hmCurr.m, m)
+		}
+		if hmCurr.isFull {
+			t.Fatalf("unexpected hmCurr.isFull; got %v; want %v", hmCurr.isFull, false)
+		}
+
+		hmPrev := s.prevHourMetricIDs.Load().(*hourMetricIDs)
+		hmEmpty := &hourMetricIDs{}
+		if !reflect.DeepEqual(hmPrev, hmEmpty) {
+			t.Fatalf("unexpected hmPrev; got %v; want %v", hmPrev, hmEmpty)
+		}
+
+		if len(s.pendingHourMetricIDs) != 0 {
+			t.Fatalf("unexpected len(s.pendingHourMetricIDs); got %d; want %d", len(s.pendingHourMetricIDs), 0)
+		}
+	})
+}
+
 func TestMetricRowMarshalUnmarshal(t *testing.T) {
 	var buf []byte
 	typ := reflect.TypeOf(&MetricRow{})

lib/storage/table.go

@@ -164,10 +164,10 @@ func (tb *table) CreateSnapshot(snapshotName string) (string, string, error) {
 		}
 	}
 
-	fs.SyncPath(dstSmallDir)
-	fs.SyncPath(dstBigDir)
-	fs.SyncPath(filepath.Dir(dstSmallDir))
-	fs.SyncPath(filepath.Dir(dstBigDir))
+	fs.MustSyncPath(dstSmallDir)
+	fs.MustSyncPath(dstBigDir)
+	fs.MustSyncPath(filepath.Dir(dstSmallDir))
+	fs.MustSyncPath(filepath.Dir(dstBigDir))
 
 	logger.Infof("created table snapshot for %q at (%q, %q) in %s", tb.path, dstSmallDir, dstBigDir, time.Since(startTime))
 	return dstSmallDir, dstBigDir, nil
@@ -176,9 +176,9 @@ func (tb *table) CreateSnapshot(snapshotName string) (string, string, error) {
 // MustDeleteSnapshot deletes snapshot with the given snapshotName.
 func (tb *table) MustDeleteSnapshot(snapshotName string) {
 	smallDir := fmt.Sprintf("%s/small/snapshots/%s", tb.path, snapshotName)
-	fs.MustRemoveAllSynced(smallDir)
+	fs.MustRemoveAll(smallDir)
 	bigDir := fmt.Sprintf("%s/big/snapshots/%s", tb.path, snapshotName)
-	fs.MustRemoveAllSynced(bigDir)
+	fs.MustRemoveAll(bigDir)
 }
 
 func (tb *table) addPartitionNolock(pt *partition) {
@@ -310,22 +310,14 @@ func (tb *table) AddRows(rows []rawRow) error {
 	// The slowest path - there are rows that don't fit any existing partition.
 	// Create new partitions for these rows.
 	// Do this under tb.ptwsLock.
-	now := timestampFromTime(time.Now())
-	minTimestamp := now - tb.retentionMilliseconds
-	maxTimestamp := now + 2*24*3600*1000 // allow max +2 days from now due to timezones shit :)
+	minTimestamp, maxTimestamp := tb.getMinMaxTimestamps()
 	tb.ptwsLock.Lock()
 	var errors []error
 	for i := range missingRows {
 		r := &missingRows[i]
 
-		if r.Timestamp < minTimestamp {
-			// Silently skip row with too small timestamp, since it should be deleted anyway.
-			continue
-		}
-		if r.Timestamp > maxTimestamp {
-			err := fmt.Errorf("cannot add row %+v with too big timestamp to table %q; the timestamp cannot be bigger than %d (+2 days from now)",
-				r, tb.path, maxTimestamp)
-			errors = append(errors, err)
+		if r.Timestamp < minTimestamp || r.Timestamp > maxTimestamp {
+			// Silently skip row outside retention, since it should be deleted anyway.
 			continue
 		}
 
@@ -359,6 +351,20 @@ func (tb *table) AddRows(rows []rawRow) error {
 	return nil
 }
 
+func (tb *table) getMinMaxTimestamps() (int64, int64) {
+	now := timestampFromTime(time.Now())
+	minTimestamp := now - tb.retentionMilliseconds
+	maxTimestamp := now + 2*24*3600*1000 // allow max +2 days from now due to timezones shit :)
+	if minTimestamp < 0 {
+		// Negative timestamps aren't supported by the storage.
+		minTimestamp = 0
+	}
+	if maxTimestamp < 0 {
+		maxTimestamp = (1 << 63) - 1
+	}
+	return minTimestamp, maxTimestamp
+}
+
 func (tb *table) startRetentionWatcher() {
 	tb.retentionWatcherWG.Add(1)
 	go func() {

lib/storage/table_search_timing_test.go

@@ -92,7 +92,7 @@ func createBenchTable(b *testing.B, path string, startTimestamp int64, rowsPerIn
 					r.Value = value
 				}
 				if err := tb.AddRows(rows); err != nil {
-					b.Fatalf("cannot add %d rows: %s", rowsPerInsert, err)
+					panic(fmt.Errorf("cannot add %d rows: %s", rowsPerInsert, err))
 				}
 			}
 			wg.Done()

lib/storage/tag_filters.go

@@ -81,6 +81,13 @@ func (tfs *TagFilters) Reset() {
 	tfs.commonPrefix = marshalCommonPrefix(tfs.commonPrefix[:0], nsPrefixTagToMetricID)
 }
 
+func (tfs *TagFilters) marshal(dst []byte) []byte {
+	for i := range tfs.tfs {
+		dst = tfs.tfs[i].Marshal(dst)
+	}
+	return dst
+}
+
 // tagFilter represents a filter used for filtering tags.
 type tagFilter struct {
 	key        []byte
@@ -161,15 +168,14 @@ func (tf *tagFilter) Init(commonPrefix, key, value []byte, isNegative, isRegexp
 			tf.isRegexp = false
 		}
 	}
-	tf.prefix = marshalTagValue(tf.prefix, prefix)
-	if tf.isRegexp {
-		// Remove the trailing tagSeparatorChar from the prefix.
-		tf.prefix = tf.prefix[:len(tf.prefix)-1]
-	}
-	if len(expr) == 0 {
+	tf.prefix = marshalTagValueNoTrailingTagSeparator(tf.prefix, prefix)
+	if !tf.isRegexp {
+		// tf contains plain value without regexp.
+		// Add empty orSuffix in order to trigger fast path for orSuffixes
+		// during the search for matching metricIDs.
+		tf.orSuffixes = append(tf.orSuffixes[:0], "")
 		return nil
 	}
-
 	rcv, err := getRegexpFromCache(expr)
 	if err != nil {
 		return err
@@ -180,16 +186,14 @@ func (tf *tagFilter) Init(commonPrefix, key, value []byte, isNegative, isRegexp
 }
 
 func (tf *tagFilter) matchSuffix(b []byte) (bool, error) {
-	if !tf.isRegexp {
-		return len(b) == 0, nil
-	}
-
-	// Remove the trailing tagSeparatorChar before applying the regexp.
+	// Remove the trailing tagSeparatorChar.
 	if len(b) == 0 || b[len(b)-1] != tagSeparatorChar {
 		return false, fmt.Errorf("unexpected end of b; want %d; b=%q", tagSeparatorChar, b)
 	}
 	b = b[:len(b)-1]
-
+	if !tf.isRegexp {
+		return len(b) == 0, nil
+	}
 	ok := tf.reSuffixMatch(b)
 	return ok, nil
 }