lib/storage: return back finalPartsToMerge from 2 to 3 in order to prevent from excessive merges in old partitions

Slow loops could require seeks and expensive regexp matching, while fast loops just scans
all the metricIDs for the given `tag=value` prefix. So these operations must have separate
max loops multiplier.

.github/workflows/main.yml

@@ -29,6 +29,7 @@ jobs:
             git diff --exit-code
             make test-full
             make test-pure
+            make test-full-386
             make victoria-metrics
             make victoria-metrics-pure
             make victoria-metrics-arm

Makefile

@@ -26,6 +26,9 @@ package: package-victoria-metrics
 release: victoria-metrics-prod
 	cd bin && tar czf victoria-metrics-$(PKG_TAG).tar.gz victoria-metrics-prod
 
+pprof-cpu:
+	go tool pprof -trim_path=github.com/VictoriaMetrics/VictoriaMetrics@ $(PPROF_FILE)
+
 fmt:
 	GO111MODULE=on gofmt -l -w -s ./lib
 	GO111MODULE=on gofmt -l -w -s ./app
@@ -61,6 +64,9 @@ test-pure:
 test-full:
 	GO111MODULE=on go test -tags=integration -mod=vendor -coverprofile=coverage.txt -covermode=atomic ./lib/... ./app/...
 
+test-full-386:
+	GO111MODULE=on GOARCH=386 go test -tags=integration -mod=vendor -coverprofile=coverage.txt -covermode=atomic ./lib/... ./app/...
+
 benchmark:
 	GO111MODULE=on go test -mod=vendor -bench=. ./lib/...
 	GO111MODULE=on go test -mod=vendor -bench=. ./app/...
@@ -89,7 +95,7 @@ install-qtc:
 
 
 golangci-lint: install-golangci-lint
-	golangci-lint run --exclude '(SA4003|SA1019):' -D errcheck
+	golangci-lint run --exclude '(SA4003|SA1019):' -D errcheck -D structcheck
 
 install-golangci-lint:
 	which golangci-lint || GO111MODULE=off go get -u github.com/golangci/golangci-lint/cmd/golangci-lint

README.md

@@ -89,6 +89,7 @@ Cluster version is available [here](https://github.com/VictoriaMetrics/VictoriaM
   - [Troubleshooting](#troubleshooting)
   - [Backfilling](#backfilling)
   - [Profiling](#profiling)
+- [Integrations](#integrations)
 - [Roadmap](#roadmap)
 - [Contacts](#contacts)
 - [Community and contributions](#community-and-contributions)
@@ -107,8 +108,8 @@ or [docker image](https://hub.docker.com/r/victoriametrics/victoria-metrics/) wi
 
 The following command-line flags are used the most:
 
-* `-storageDataPath` - path to data directory. VictoriaMetrics stores all the data in this directory.
-* `-retentionPeriod` - retention period in months for the data. Older data is automatically deleted.
+* `-storageDataPath` - path to data directory. VictoriaMetrics stores all the data in this directory. Default path is `victoria-metrics-data` in current working directory.
+* `-retentionPeriod` - retention period in months for the data. Older data is automatically deleted. Default period is 1 month.
 * `-httpListenAddr` - TCP address to listen to for http requests. By default, it listens port `8428` on all the network interfaces.
 * `-graphiteListenAddr` - TCP and UDP address to listen to for Graphite data. By default, it is disabled.
 * `-opentsdbListenAddr` - TCP and UDP address to listen to for OpenTSDB data over telnet protocol. By default, it is disabled.
@@ -156,7 +157,7 @@ The label name may be arbitrary - `datacenter` is just an example. The label val
 across Prometheus instances, so those 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,
+It is recommended upgrading Prometheus to [v2.12.0](https://github.com/prometheus/prometheus/releases) or newer,
 since the previous versions may have issues with `remote_write`.
 
 
@@ -253,8 +254,8 @@ curl -G 'http://localhost:8428/api/v1/export' -d '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]}
+{"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]}
 ```
 
 Note that Influx line protocol expects [timestamps in *nanoseconds* by default](https://docs.influxdata.com/influxdb/v1.7/write_protocols/line_protocol_tutorial/#timestamp),
@@ -511,7 +512,7 @@ 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. The default value for `max_lookback` is `5m` (5 minutes), but can be overridden.
+on the interval `[now - max_lookback ... now]` is scraped for each time series. The default value for `max_lookback` is `5m` (5 minutes), but it 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`.
 
@@ -527,7 +528,7 @@ A rough estimation of the required resources for ingestion path:
   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 ingestion rate may be lower for high cardinality data.
+  the insert stream of 1M data points per second. The ingestion rate may be lower for high cardinality data or for time series with high number of labels.
   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.
@@ -652,6 +653,14 @@ For example, substitute `-graphiteListenAddr=:2003` with `-graphiteListenAddr=<i
 * There is no need in Operating System tuning since VictoriaMetrics is optimized for default OS settings.
   The only option is increasing the limit on [the number of open files in the OS](https://medium.com/@muhammadtriwibowo/set-permanently-ulimit-n-open-files-in-ubuntu-4d61064429a),
   so Prometheus instances could establish more connections to VictoriaMetrics.
+* The recommended filesystem is `ext4`, the recommended persistent storage is [persistent HDD-based disk on GCP](https://cloud.google.com/compute/docs/disks/#pdspecs),
+  since it is protected from hardware failures via internal replication and it can be [resized on the fly](https://cloud.google.com/compute/docs/disks/add-persistent-disk#resize_pd).
+  If you plan storing more than 1TB of data on `ext4` partition or plan extending it to more than 16TB,
+  then the following options are recommended to pass to `mkfs.ext4`:
+
+```
+mkfs.ext4 ... -O 64bit,huge_file,extent -T huge
+```
 
 
 ### Monitoring
@@ -664,10 +673,7 @@ 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.
+* `vm_rows{type="indexdb"}` - the number of rows in inverted index. High value for this number usually mean high churn rate for 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.
@@ -678,6 +684,9 @@ The most interesting metrics are:
 
 ### Troubleshooting
 
+* It is recommended to use default command-line flag values (i.e. don't set them explicitly) until the need
+  in tweaking these flag values arises.
+
 * If VictoriaMetrics works slowly and eats more than a CPU core per 100K ingested data points per second,
   then it is likely you have too many active time series for the current amount of RAM.
   It is recommended increasing the amount of RAM on the node with VictoriaMetrics in order to improve
@@ -723,6 +732,14 @@ The command for collecting CPU profile waits for 30 seconds before returning.
 The collected profiles may be analyzed with [go tool pprof](https://github.com/google/pprof).
 
 
+## Integrations
+
+* [netdata](https://github.com/netdata/netdata) can push data into VictoriaMetrics via `Prometheus remote_write API`.
+  See [these docs](https://github.com/netdata/netdata#integrations).
+* [go-graphite/carbonapi](https://github.com/go-graphite/carbonapi) can use VictoriaMetrics as time series backend.
+  See [this example](/blob/master/cmd/carbonapi/carbonapi.example.prometheus.yaml).
+
+
 ## Roadmap
 
 - [ ] Replication [#118](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/118)
@@ -745,8 +762,8 @@ Contact us with any questions regarding VictoriaMetrics at [info@victoriametrics
 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)
+- [telegram-en](https://t.me/VictoriaMetrics_en)
+- [telegram-ru](https://t.me/VictoriaMetrics_ru1)
 - [google groups](https://groups.google.com/forum/#!forum/victorametrics-users)
 
 

app/victoria-metrics/Makefile

@@ -32,6 +32,12 @@ victoria-metrics-arm64:
 victoria-metrics-arm64-prod:
 	APP_NAME=victoria-metrics APP_SUFFIX='-arm64' DOCKER_OPTS='--env CGO_ENABLED=0 --env GOARCH=arm64' $(MAKE) app-via-docker
 
+victoria-metrics-386:
+	CGO_ENABLED=0 GOOS=linux GOARCH=386 GO111MODULE=on go build -mod=vendor -ldflags "$(GO_BUILDINFO)" -o bin/victoria-metrics-386 ./app/victoria-metrics
+
+victoria-metrics-386-prod:
+	APP_NAME=victoria-metrics APP_SUFFIX='-386' DOCKER_OPTS='--env CGO_ENABLED=0 --env GOARCH=386' $(MAKE) app-via-docker
+
 victoria-metrics-pure:
 	APP_NAME=victoria-metrics $(MAKE) app-local-pure
 

app/victoria-metrics/main_test.go

@@ -50,52 +50,73 @@ const (
 	testStorageInitTimeout = 10 * time.Second
 )
 
-const (
-	tplWordTime              = "{TIME}"
-	tplQuotedWordTimeSeconds = `"{TIME_S}"`
-	tplQuotedWordTimeMillis  = `"{TIME_MS}"`
-)
-
 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"`
+	Name             string     `json:"name"`
+	Data             []string   `json:"data"`
+	Query            []string   `json:"query"`
+	ResultMetrics    []Metric   `json:"result_metrics"`
+	ResultSeries     Series     `json:"result_series"`
+	ResultQuery      Query      `json:"result_query"`
+	ResultQueryRange QueryRange `json:"result_query_range"`
+	Issue            string     `json:"issue"`
 }
 
-type Row struct {
+type Metric struct {
 	Metric     map[string]string `json:"metric"`
 	Values     []float64         `json:"values"`
 	Timestamps []int64           `json:"timestamps"`
 }
 
-func (r *Row) UnmarshalJSON(b []byte) error {
-	type withoutInterface Row
-	var to withoutInterface
-	if err := json.Unmarshal(populateTimeTpl(b), &to); err != nil {
-		return err
-	}
-	*r = Row(to)
-	return nil
+func (r *Metric) UnmarshalJSON(b []byte) error {
+	type plain Metric
+	return json.Unmarshal(testutil.PopulateTimeTpl(b, insertionTime), (*plain)(r))
 }
 
-func populateTimeTpl(b []byte) []byte {
-	var (
-		tplTimeToQuotedMS = [2][]byte{[]byte(tplQuotedWordTimeMillis), []byte(fmt.Sprintf("%d", timeToMillis(insertionTime)))}
-		tpsTimeToQuotedS  = [2][]byte{[]byte(tplQuotedWordTimeSeconds), []byte(fmt.Sprintf("%d", insertionTime.Unix()*1e3))}
-	)
-	tpls := [][2][]byte{
-		tplTimeToQuotedMS, tpsTimeToQuotedS,
-	}
-	for i := range tpls {
-		b = bytes.ReplaceAll(b, tpls[i][0], tpls[i][1])
-	}
-	return b
+type Series struct {
+	Status string              `json:"status"`
+	Data   []map[string]string `json:"data"`
+}
+type Query struct {
+	Status string    `json:"status"`
+	Data   QueryData `json:"data"`
+}
+type QueryData struct {
+	ResultType string            `json:"resultType"`
+	Result     []QueryDataResult `json:"result"`
+}
+
+type QueryDataResult struct {
+	Metric map[string]string `json:"metric"`
+	Value  []interface{}     `json:"value"`
+}
+
+func (r *QueryDataResult) UnmarshalJSON(b []byte) error {
+	type plain QueryDataResult
+	return json.Unmarshal(testutil.PopulateTimeTpl(b, insertionTime), (*plain)(r))
+}
+
+type QueryRange struct {
+	Status string         `json:"status"`
+	Data   QueryRangeData `json:"data"`
+}
+type QueryRangeData struct {
+	ResultType string                 `json:"resultType"`
+	Result     []QueryRangeDataResult `json:"result"`
+}
+
+type QueryRangeDataResult struct {
+	Metric map[string]string `json:"metric"`
+	Values [][]interface{}   `json:"values"`
+}
+
+func (r *QueryRangeDataResult) UnmarshalJSON(b []byte) error {
+	type plain QueryRangeDataResult
+	return json.Unmarshal(testutil.PopulateTimeTpl(b, insertionTime), (*plain)(r))
 }
 
 func TestMain(m *testing.M) {
@@ -179,10 +200,10 @@ func TestWriteRead(t *testing.T) {
 
 func testWrite(t *testing.T) {
 	t.Run("prometheus", func(t *testing.T) {
-		for _, test := range readIn("prometheus", t, fmt.Sprintf("%d", timeToMillis(insertionTime))) {
+		for _, test := range readIn("prometheus", t, insertionTime) {
 			s := newSuite(t)
 			r := testutil.WriteRequest{}
-			s.noError(json.Unmarshal([]byte(test.Data), &r.Timeseries))
+			s.noError(json.Unmarshal([]byte(strings.Join(test.Data, "\n")), &r.Timeseries))
 			data, err := testutil.Compress(r)
 			s.greaterThan(len(r.Timeseries), 0)
 			if err != nil {
@@ -194,39 +215,39 @@ func testWrite(t *testing.T) {
 	})
 
 	t.Run("influxdb", func(t *testing.T) {
-		for _, x := range readIn("influxdb", t, fmt.Sprintf("%d", insertionTime.UnixNano())) {
+		for _, x := range readIn("influxdb", t, insertionTime) {
 			test := x
 			t.Run(test.Name, func(t *testing.T) {
 				t.Parallel()
-				httpWrite(t, testWriteHTTPPath, bytes.NewBufferString(test.Data))
+				httpWrite(t, testWriteHTTPPath, bytes.NewBufferString(strings.Join(test.Data, "\n")))
 			})
 		}
 	})
 	t.Run("graphite", func(t *testing.T) {
-		for _, x := range readIn("graphite", t, fmt.Sprintf("%d", insertionTime.Unix())) {
+		for _, x := range readIn("graphite", t, insertionTime) {
 			test := x
 			t.Run(test.Name, func(t *testing.T) {
 				t.Parallel()
-				tcpWrite(t, "127.0.0.1"+testStatsDListenAddr, test.Data)
+				tcpWrite(t, "127.0.0.1"+testStatsDListenAddr, strings.Join(test.Data, "\n"))
 			})
 		}
 	})
 	t.Run("opentsdb", func(t *testing.T) {
-		for _, x := range readIn("opentsdb", t, fmt.Sprintf("%d", insertionTime.Unix())) {
+		for _, x := range readIn("opentsdb", t, insertionTime) {
 			test := x
 			t.Run(test.Name, func(t *testing.T) {
 				t.Parallel()
-				tcpWrite(t, "127.0.0.1"+testOpenTSDBListenAddr, test.Data)
+				tcpWrite(t, "127.0.0.1"+testOpenTSDBListenAddr, strings.Join(test.Data, "\n"))
 			})
 		}
 	})
 	t.Run("opentsdbhttp", func(t *testing.T) {
-		for _, x := range readIn("opentsdbhttp", t, fmt.Sprintf("%d", insertionTime.Unix())) {
+		for _, x := range readIn("opentsdbhttp", t, insertionTime) {
 			test := x
 			t.Run(test.Name, func(t *testing.T) {
 				t.Parallel()
 				logger.Infof("writing %s", test.Data)
-				httpWrite(t, testOpenTSDBWriteHTTPPath, bytes.NewBufferString(test.Data))
+				httpWrite(t, testOpenTSDBWriteHTTPPath, bytes.NewBufferString(strings.Join(test.Data, "\n")))
 			})
 		}
 	})
@@ -235,18 +256,49 @@ func testWrite(t *testing.T) {
 func testRead(t *testing.T) {
 	for _, engine := range []string{"prometheus", "graphite", "opentsdb", "influxdb", "opentsdbhttp"} {
 		t.Run(engine, func(t *testing.T) {
-			for _, x := range readIn(engine, t, fmt.Sprintf("%d", insertionTime.UnixNano())) {
+			for _, x := range readIn(engine, t, insertionTime) {
 				test := x
 				t.Run(test.Name, func(t *testing.T) {
 					t.Parallel()
-					rowContains(t, httpRead(t, testReadHTTPPath, test.Query), test.Result)
+					for _, q := range test.Query {
+						q = testutil.PopulateTimeTplString(q, insertionTime)
+						if test.Issue != "" {
+							test.Issue = "Regression in " + test.Issue
+						}
+						switch true {
+						case strings.HasPrefix(q, "/api/v1/export"):
+							if err := checkMetricsResult(httpReadMetrics(t, testReadHTTPPath, q), test.ResultMetrics); err != nil {
+								t.Fatalf("Export. %s fails with error %s.%s", q, err, test.Issue)
+							}
+						case strings.HasPrefix(q, "/api/v1/series"):
+							s := Series{}
+							httpReadStruct(t, testReadHTTPPath, q, &s)
+							if err := checkSeriesResult(s, test.ResultSeries); err != nil {
+								t.Fatalf("Series. %s fails with error %s.%s", q, err, test.Issue)
+							}
+						case strings.HasPrefix(q, "/api/v1/query_range"):
+							queryResult := QueryRange{}
+							httpReadStruct(t, testReadHTTPPath, q, &queryResult)
+							if err := checkQueryRangeResult(queryResult, test.ResultQueryRange); err != nil {
+								t.Fatalf("Query Range. %s fails with error %s.%s", q, err, test.Issue)
+							}
+						case strings.HasPrefix(q, "/api/v1/query"):
+							queryResult := Query{}
+							httpReadStruct(t, testReadHTTPPath, q, &queryResult)
+							if err := checkQueryResult(queryResult, test.ResultQuery); err != nil {
+								t.Fatalf("Query. %s fails with error %s.%s", q, err, test.Issue)
+							}
+						default:
+							t.Fatalf("unsupported read query %s", q)
+						}
+					}
 				})
 			}
 		})
 	}
 }
 
-func readIn(readFor string, t *testing.T, timeStr string) []test {
+func readIn(readFor string, t *testing.T, insertTime time.Time) []test {
 	t.Helper()
 	s := newSuite(t)
 	var tt []test
@@ -258,7 +310,9 @@ func readIn(readFor string, t *testing.T, timeStr string) []test {
 		s.noError(err)
 		item := test{}
 		s.noError(json.Unmarshal(b, &item))
-		item.Data = strings.Replace(item.Data, tplWordTime, timeStr, -1)
+		for i := range item.Data {
+			item.Data[i] = testutil.PopulateTimeTplString(item.Data[i], insertTime)
+		}
 		tt = append(tt, item)
 		return nil
 	}))
@@ -288,33 +342,42 @@ func tcpWrite(t *testing.T, address string, data string) {
 	s.equalInt(n, len(data))
 }
 
-func httpRead(t *testing.T, address, query string) []Row {
+func httpReadMetrics(t *testing.T, address, query string) []Metric {
 	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
+	var rows []Metric
 	for dec := json.NewDecoder(resp.Body); dec.More(); {
-		var row Row
+		var row Metric
 		s.noError(dec.Decode(&row))
 		rows = append(rows, row)
 	}
 	return rows
 }
-
-func rowContains(t *testing.T, rows, contains []Row) {
+func httpReadStruct(t *testing.T, address, query string, dst interface{}) {
 	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)
-	}
+	s := newSuite(t)
+	resp, err := http.Get(address + query)
+	s.noError(err)
+	defer resp.Body.Close()
+	s.equalInt(resp.StatusCode, 200)
+	s.noError(json.NewDecoder(resp.Body).Decode(dst))
 }
 
-func removeIfFound(r Row, contains []Row) []Row {
+func checkMetricsResult(got, want []Metric) error {
+	for _, r := range append([]Metric(nil), got...) {
+		want = removeIfFoundMetrics(r, want)
+	}
+	if len(want) > 0 {
+		return fmt.Errorf("exptected metrics %+v not found in %+v", want, got)
+	}
+	return nil
+}
+
+func removeIfFoundMetrics(r Metric, contains []Metric) []Metric {
 	for i, item := range contains {
 		if reflect.DeepEqual(r.Metric, item.Metric) && reflect.DeepEqual(r.Values, item.Values) &&
 			reflect.DeepEqual(r.Timestamps, item.Timestamps) {
@@ -325,6 +388,84 @@ func removeIfFound(r Row, contains []Row) []Row {
 	return contains
 }
 
+func checkSeriesResult(got, want Series) error {
+	if got.Status != want.Status {
+		return fmt.Errorf("status mismatch %q - %q", want.Status, got.Status)
+	}
+	wantData := append([]map[string]string(nil), want.Data...)
+	for _, r := range got.Data {
+		wantData = removeIfFoundSeries(r, wantData)
+	}
+	if len(wantData) > 0 {
+		return fmt.Errorf("expected seria(s) %+v not found in %+v", wantData, got.Data)
+	}
+	return nil
+}
+
+func removeIfFoundSeries(r map[string]string, contains []map[string]string) []map[string]string {
+	for i, item := range contains {
+		if reflect.DeepEqual(r, item) {
+			contains[i] = contains[len(contains)-1]
+			return contains[:len(contains)-1]
+		}
+	}
+	return contains
+}
+
+func checkQueryResult(got, want Query) error {
+	if got.Status != want.Status {
+		return fmt.Errorf("status mismatch %q - %q", want.Status, got.Status)
+	}
+	if got.Data.ResultType != want.Data.ResultType {
+		return fmt.Errorf("result type mismatch %q - %q", want.Data.ResultType, got.Data.ResultType)
+	}
+	wantData := append([]QueryDataResult(nil), want.Data.Result...)
+	for _, r := range got.Data.Result {
+		wantData = removeIfFoundQueryData(r, wantData)
+	}
+	if len(wantData) > 0 {
+		return fmt.Errorf("expected query result %+v not found in %+v", wantData, got.Data.Result)
+	}
+	return nil
+}
+
+func removeIfFoundQueryData(r QueryDataResult, contains []QueryDataResult) []QueryDataResult {
+	for i, item := range contains {
+		if reflect.DeepEqual(r.Metric, item.Metric) && reflect.DeepEqual(r.Value[0], item.Value[0]) && reflect.DeepEqual(r.Value[1], item.Value[1]) {
+			contains[i] = contains[len(contains)-1]
+			return contains[:len(contains)-1]
+		}
+	}
+	return contains
+}
+
+func checkQueryRangeResult(got, want QueryRange) error {
+	if got.Status != want.Status {
+		return fmt.Errorf("status mismatch %q - %q", want.Status, got.Status)
+	}
+	if got.Data.ResultType != want.Data.ResultType {
+		return fmt.Errorf("result type mismatch %q - %q", want.Data.ResultType, got.Data.ResultType)
+	}
+	wantData := append([]QueryRangeDataResult(nil), want.Data.Result...)
+	for _, r := range got.Data.Result {
+		wantData = removeIfFoundQueryRangeData(r, wantData)
+	}
+	if len(wantData) > 0 {
+		return fmt.Errorf("expected query range result %+v not found in %+v", wantData, got.Data.Result)
+	}
+	return nil
+}
+
+func removeIfFoundQueryRangeData(r QueryRangeDataResult, contains []QueryRangeDataResult) []QueryRangeDataResult {
+	for i, item := range contains {
+		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} }
@@ -352,7 +493,3 @@ func (s *suite) greaterThan(a, b int) {
 		s.t.FailNow()
 	}
 }
-
-func timeToMillis(t time.Time) int64 {
-	return t.UnixNano() / 1e6
-}

app/victoria-metrics/test/parser.go

@@ -0,0 +1,52 @@
+package test
+
+import (
+	"fmt"
+	"log"
+	"regexp"
+	"strings"
+	"time"
+)
+
+var (
+	parseTimeExpRegex = regexp.MustCompile(`"?{TIME[^}]*}"?`)
+	extractRegex      = regexp.MustCompile(`"?{([^}]*)}"?`)
+)
+
+// PopulateTimeTplString substitutes {TIME_*} with t in s and returns the result.
+func PopulateTimeTplString(s string, t time.Time) string {
+	return string(PopulateTimeTpl([]byte(s), t))
+}
+
+// PopulateTimeTpl substitutes {TIME_*} with tGlobal in b and returns the result.
+func PopulateTimeTpl(b []byte, tGlobal time.Time) []byte {
+	return parseTimeExpRegex.ReplaceAllFunc(b, func(repl []byte) []byte {
+		t := tGlobal
+		repl = extractRegex.FindSubmatch(repl)[1]
+		parts := strings.SplitN(string(repl), "-", 2)
+		if len(parts) == 2 {
+			duration, err := time.ParseDuration(strings.TrimSpace(parts[1]))
+			if err != nil {
+				log.Fatalf("error %s parsing duration %s in %s", err, parts[1], repl)
+			}
+			t = t.Add(-duration)
+		}
+		switch strings.TrimSpace(parts[0]) {
+		case `TIME_S`:
+			return []byte(fmt.Sprintf("%d", t.Unix()))
+		case `TIME_MSZ`:
+			return []byte(fmt.Sprintf("%d", t.Unix()*1e3))
+		case `TIME_MS`:
+			return []byte(fmt.Sprintf("%d", timeToMillis(t)))
+		case `TIME_NS`:
+			return []byte(fmt.Sprintf("%d", t.UnixNano()))
+		default:
+			log.Fatalf("unkown time pattern %s in %s", parts[0], repl)
+		}
+		return repl
+	})
+}
+
+func timeToMillis(t time.Time) int64 {
+	return t.UnixNano() / 1e6
+}

app/victoria-metrics/test/parser_test.go

@@ -0,0 +1,24 @@
+package test
+
+import (
+	"testing"
+	"time"
+)
+
+func TestPopulateTimeTplString(t *testing.T) {
+	now, err := time.Parse(time.RFC3339, "2006-01-02T15:04:05Z")
+	if err != nil {
+		t.Fatalf("unexpected error when parsing time: %s", err)
+	}
+	f := func(s, resultExpected string) {
+		t.Helper()
+		result := PopulateTimeTplString(s, now)
+		if result != resultExpected {
+			t.Fatalf("unexpected result; got %q; want %q", result, resultExpected)
+		}
+	}
+	f("", "")
+	f("{TIME_S}", "1136214245")
+	f("now: {TIME_S}, past 30s: {TIME_MS-30s}, now: {TIME_S}", "now: 1136214245, past 30s: 1136214215000, now: 1136214245")
+	f("now: {TIME_MS}, past 30m: {TIME_MSZ-30m}, past 2h: {TIME_NS-2h}", "now: 1136214245000, past 30m: 1136212445000, past 2h: 1136207045000000000")
+}

app/victoria-metrics/test/prom_types.go

@@ -5,7 +5,6 @@ package test
 
 import (
 	"encoding/binary"
-	"log"
 	"math"
 	"math/bits"
 )
@@ -124,7 +123,6 @@ func (m *Sample) MarshalTo(dAtA []byte) (int, error) {
 func (m *Sample) MarshalToSizedBuffer(dAtA []byte) (int, error) {
 	i := len(dAtA)
 	if m.Timestamp != 0 {
-		log.Printf("prom types %d", m.Timestamp)
 		i = encodeVarintTypes(dAtA, i, uint64(m.Timestamp))
 		i--
 		dAtA[i] = 0x10

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

@@ -1,8 +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], "timestamps": ["{TIME_S}"]}
+  "data": ["graphite.foo.bar.baz;tag1=value1;tag2=value2 123 {TIME_S}"],
+  "query": ["/api/v1/export?match={__name__!=''}"],
+  "result_metrics": [
+    {"metric":{"__name__":"graphite.foo.bar.baz","tag1":"value1","tag2":"value2"},"values":[123], "timestamps": ["{TIME_MSZ}"]}
   ]
 }

app/victoria-metrics/testdata/graphite/comparison-not-inf-not-nan.json

@@ -0,0 +1,16 @@
+{
+  "name": "comparison-not-inf-not-nan",
+  "issue": "https://github.com/VictoriaMetrics/VictoriaMetrics/issues/150",
+  "data": [
+    "not_nan_not_inf;item=x 1 {TIME_S-1m}",
+    "not_nan_not_inf;item=x 1 {TIME_S-2m}",
+    "not_nan_not_inf;item=y 3 {TIME_S-1m}",
+    "not_nan_not_inf;item=y 1 {TIME_S-2m}"],
+  "query": ["/api/v1/query_range?query=1/(not_nan_not_inf-1)!=inf!=nan&start={TIME_S-3m}&end={TIME_S}&step=60"],
+  "result_query_range": {
+    "status":"success",
+    "data":{"resultType":"matrix",
+      "result":[
+	      {"metric":{"item":"y"},"values":[["{TIME_S-1m}","0.5"],["{TIME_S}","0.5"]]}
+      ]}}
+}

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

@@ -0,0 +1,24 @@
+{
+  "name": "max_lookback_set",
+  "issue": "https://github.com/VictoriaMetrics/VictoriaMetrics/issues/209",
+  "data": [
+    "max_lookback_set 1 {TIME_S-30s}",
+    "max_lookback_set 2 {TIME_S-60s}",
+    "max_lookback_set 3 {TIME_S-120s}",
+    "max_lookback_set 4 {TIME_S-150s}"
+  ],
+  "query": ["/api/v1/query_range?query=max_lookback_set&start={TIME_S-150s}&end={TIME_S}&step=10s&max_lookback=1s"],
+  "result_query_range": {
+    "status":"success",
+    "data":{"resultType":"matrix",
+      "result":[{"metric":{"__name__":"max_lookback_set"},"values":[
+	      ["{TIME_S-150s}","4"],
+	      ["{TIME_S-140s}","4"],
+	      ["{TIME_S-120s}","3"],
+	      ["{TIME_S-110s}","3"],
+	      ["{TIME_S-60s}","2"],
+	      ["{TIME_S-50s}","2"],
+	      ["{TIME_S-30s}","1"],
+	      ["{TIME_S-20s}","1"]
+      ]}]}}
+}

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

@@ -0,0 +1,32 @@
+{
+  "name": "max_lookback_unset",
+  "issue": "https://github.com/VictoriaMetrics/VictoriaMetrics/issues/209",
+  "data": [
+    "max_lookback_unset 1 {TIME_S-30s}",
+    "max_lookback_unset 2 {TIME_S-60s}",
+    "max_lookback_unset 3 {TIME_S-120s}",
+    "max_lookback_unset 4 {TIME_S-150s}"
+  ],
+  "query": ["/api/v1/query_range?query=max_lookback_unset&start={TIME_S-150s}&end={TIME_S}&step=10s"],
+  "result_query_range": {
+    "status":"success",
+    "data":{"resultType":"matrix",
+      "result":[{"metric":{"__name__":"max_lookback_unset"},"values":[
+	      ["{TIME_S-150s}","4"],
+	      ["{TIME_S-140s}","4"],
+	      ["{TIME_S-130s}","4"],
+	      ["{TIME_S-120s}","3"],
+	      ["{TIME_S-110s}","3"],
+	      ["{TIME_S-100s}","3"],
+	      ["{TIME_S-90s}","3"],
+	      ["{TIME_S-80s}","3"],
+	      ["{TIME_S-70s}","3"],
+	      ["{TIME_S-60s}","2"],
+	      ["{TIME_S-50s}","2"],
+	      ["{TIME_S-40s}","2"],
+	      ["{TIME_S-30s}","1"],
+	      ["{TIME_S-20s}","1"],
+	      ["{TIME_S-10s}","1"],
+	      ["{TIME_S}","1"]
+      ]}]}}
+}

app/victoria-metrics/testdata/graphite/not-nan-as-missing-data.json

@@ -0,0 +1,18 @@
+{
+  "name": "not-nan-as-missing-data",
+  "issue": "https://github.com/VictoriaMetrics/VictoriaMetrics/issues/153",
+  "data": [
+    "not_nan_as_missing_data;item=x 2 {TIME_S-2m}",
+    "not_nan_as_missing_data;item=x 1 {TIME_S-1m}",
+    "not_nan_as_missing_data;item=y 4 {TIME_S-2m}",
+    "not_nan_as_missing_data;item=y 3 {TIME_S-1m}"
+  ],
+  "query": ["/api/v1/query_range?query=not_nan_as_missing_data>1&start={TIME_S-2m}&end={TIME_S}&step=60"],
+  "result_query_range": {
+    "status":"success",
+    "data":{"resultType":"matrix",
+      "result":[
+	      {"metric":{"__name__":"not_nan_as_missing_data","item":"x"},"values":[["{TIME_S-2m}","2"]]},
+	      {"metric":{"__name__":"not_nan_as_missing_data","item":"y"},"values":[["{TIME_S-2m}","4"],["{TIME_S-1m}","3"],["{TIME_S}","3"]]}
+      ]}}
+}

app/victoria-metrics/testdata/graphite/subquery-aggregation.json

@@ -0,0 +1,14 @@
+{
+  "name": "subquery-aggregation",
+  "issue": "https://github.com/VictoriaMetrics/VictoriaMetrics/issues/184",
+  "data": [
+    "forms_daily_count;item=x 1 {TIME_S-1m}",
+    "forms_daily_count;item=x 2 {TIME_S-2m}",
+    "forms_daily_count;item=y 3 {TIME_S-1m}",
+    "forms_daily_count;item=y 4 {TIME_S-2m}"],
+  "query": ["/api/v1/query?query=min%20by%20(item)%20(min_over_time(forms_daily_count[10m:1m]))&time={TIME_S-1m}"],
+  "result_query": {
+    "status":"success",
+    "data":{"resultType":"vector","result":[{"metric":{"item":"x"},"value":["{TIME_S-1m}","1"]},{"metric":{"item":"y"},"value":["{TIME_S-1m}","3"]}]}
+  }
+}

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

@@ -1,8 +1,8 @@
 {
   "name": "basic_insertion",
-  "data": "measurement,tag1=value1,tag2=value2 field1=1.23,field2=123 {TIME}",
-  "query": "/api/v1/export?match={__name__!=\"\"}",
-  "result": [
+  "data": ["measurement,tag1=value1,tag2=value2 field1=1.23,field2=123 {TIME_NS}"],
+  "query": ["/api/v1/export?match={__name__!=''}"],
+  "result_metrics": [
     {"metric":{"__name__":"measurement_field2","tag1":"value1","tag2":"value2"},"values":[123], "timestamps": ["{TIME_MS}"]},
     {"metric":{"__name__":"measurement_field1","tag1":"value1","tag2":"value2"},"values":[1.23], "timestamps": ["{TIME_MS}"]}
   ]

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

@@ -1,8 +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], "timestamps": ["{TIME_S}"]}
+  "data": ["put openstdb.foo.bar.baz {TIME_S} 123 tag1=value1 tag2=value2"],
+  "query": ["/api/v1/export?match={__name__!=''}"],
+  "result_metrics": [
+    {"metric":{"__name__":"openstdb.foo.bar.baz","tag1":"value1","tag2":"value2"},"values":[123], "timestamps": ["{TIME_MSZ}"]}
   ]
 }

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

@@ -1,8 +1,8 @@
 {
   "name": "basic_insertion",
-  "data": "{\"metric\": \"opentsdbhttp.foo\", \"value\": 1001, \"timestamp\": {TIME}, \"tags\": {\"bar\":\"baz\", \"x\": \"y\"}}",
-  "query": "/api/v1/export?match={__name__!=\"\"}",
-  "result": [
-    {"metric":{"__name__":"opentsdbhttp.foo","bar":"baz","x":"y"},"values":[1001], "timestamps": ["{TIME_S}"]}
+  "data": ["{\"metric\": \"opentsdbhttp.foo\", \"value\": 1001, \"timestamp\": {TIME_S}, \"tags\": {\"bar\":\"baz\", \"x\": \"y\"}}"],
+  "query": ["/api/v1/export?match={__name__!=''}"],
+  "result_metrics": [
+    {"metric":{"__name__":"opentsdbhttp.foo","bar":"baz","x":"y"},"values":[1001], "timestamps": ["{TIME_MSZ}"]}
   ]
 }

app/victoria-metrics/testdata/opentsdbhttp/multi_line.json

@@ -1,9 +1,9 @@
 {
   "name": "multiline",
-  "data": "[{\"metric\": \"opentsdbhttp.multiline1\", \"value\": 1001, \"timestamp\": \"{TIME}\", \"tags\": {\"bar\":\"baz\", \"x\": \"y\"}}, {\"metric\": \"opentsdbhttp.multiline2\", \"value\": 1002, \"timestamp\": {TIME}}]",
-  "query": "/api/v1/export?match={__name__!=\"\"}",
-  "result": [
-    {"metric":{"__name__":"opentsdbhttp.multiline1","bar":"baz","x":"y"},"values":[1001], "timestamps": ["{TIME_S}"]},
-    {"metric":{"__name__":"opentsdbhttp.multiline2"},"values":[1002], "timestamps": ["{TIME_S}"]}
+  "data": ["[{\"metric\": \"opentsdbhttp.multiline1\", \"value\": 1001, \"timestamp\": \"{TIME_S}\", \"tags\": {\"bar\":\"baz\", \"x\": \"y\"}}, {\"metric\": \"opentsdbhttp.multiline2\", \"value\": 1002, \"timestamp\": {TIME_S}}]"],
+  "query": ["/api/v1/export?match={__name__!=''}"],
+  "result_metrics": [
+    {"metric":{"__name__":"opentsdbhttp.multiline1","bar":"baz","x":"y"},"values":[1001], "timestamps": ["{TIME_MSZ}"]},
+    {"metric":{"__name__":"opentsdbhttp.multiline2"},"values":[1002], "timestamps": ["{TIME_MSZ}"]}
   ]
 }

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

@@ -1,8 +1,8 @@
 {
   "name": "basic_insertion",
-  "data": "[{\"labels\":[{\"name\":\"__name__\",\"value\":\"prometheus.bar\"},{\"name\":\"baz\",\"value\":\"qux\"}],\"samples\":[{\"value\":100000,\"timestamp\":{TIME}}]}]",
-  "query": "/api/v1/export?match={__name__!=\"\"}",
-  "result": [
+  "data": ["[{\"labels\":[{\"name\":\"__name__\",\"value\":\"prometheus.bar\"},{\"name\":\"baz\",\"value\":\"qux\"}],\"samples\":[{\"value\":100000,\"timestamp\":\"{TIME_MS}\"}]}]"],
+  "query": ["/api/v1/export?match={__name__!=''}"],
+  "result_metrics": [
     {"metric":{"__name__":"prometheus.bar","baz":"qux"},"values":[100000], "timestamps": ["{TIME_MS}"]}
   ]
 }

app/victoria-metrics/testdata/prometheus/case-sensitive-regex.json

@@ -0,0 +1,10 @@
+{
+  "name": "case-sensitive-regex",
+  "issue": "https://github.com/VictoriaMetrics/VictoriaMetrics/issues/161",
+  "data": ["[{\"labels\":[{\"name\":\"__name__\",\"value\":\"prometheus.sensitiveRegex\"},{\"name\":\"label\",\"value\":\"sensitiveRegex\"}],\"samples\":[{\"value\":2,\"timestamp\":\"{TIME_MS}\"}]},{\"labels\":[{\"name\":\"__name__\",\"value\":\"prometheus.sensitiveRegex\"},{\"name\":\"label\",\"value\":\"SensitiveRegex\"}],\"samples\":[{\"value\":1,\"timestamp\":\"{TIME_MS}\"}]}]"],
+  "query": ["/api/v1/export?match={label=~'(?i)sensitiveregex'}"],
+  "result_metrics": [
+    {"metric":{"__name__":"prometheus.sensitiveRegex","label":"sensitiveRegex"},"values":[2], "timestamps": ["{TIME_MS}"]},
+    {"metric":{"__name__":"prometheus.sensitiveRegex","label":"SensitiveRegex"},"values":[1], "timestamps": ["{TIME_MS}"]}
+  ]
+}

app/victoria-metrics/testdata/prometheus/duplicate-label.json

@@ -0,0 +1,9 @@
+{
+  "name": "duplicate_label",
+  "issue": "https://github.com/VictoriaMetrics/VictoriaMetrics/issues/172",
+  "data": ["[{\"labels\":[{\"name\":\"__name__\",\"value\":\"prometheus.duplicate_label\"},{\"name\":\"duplicate\",\"value\":\"label\"},{\"name\":\"duplicate\",\"value\":\"label\"}],\"samples\":[{\"value\":1,\"timestamp\":\"{TIME_MS}\"}]}]"],
+  "query": ["/api/v1/export?match={__name__!=''}"],
+  "result_metrics": [
+    {"metric":{"__name__":"prometheus.duplicate_label","duplicate":"label"},"values":[1], "timestamps": ["{TIME_MS}"]}
+  ]
+}

app/victoria-metrics/testdata/prometheus/match-series.json

@@ -0,0 +1,15 @@
+{
+  "name": "match_series",
+  "issue": "https://github.com/VictoriaMetrics/VictoriaMetrics/issues/155",
+  "data": ["[{\"labels\":[{\"name\":\"__name__\",\"value\":\"MatchSeries\"},{\"name\":\"db\",\"value\":\"TenMinute\"},{\"name\":\"TurbineType\",\"value\":\"V112\"},{\"name\":\"Park\",\"value\":\"1\"}],\"samples\":[{\"value\":1,\"timestamp\":\"{TIME_MS}\"}]},{\"labels\":[{\"name\":\"__name__\",\"value\":\"MatchSeries\"},{\"name\":\"db\",\"value\":\"TenMinute\"},{\"name\":\"TurbineType\",\"value\":\"V112\"},{\"name\":\"Park\",\"value\":\"2\"}],\"samples\":[{\"value\":1,\"timestamp\":\"{TIME_MS}\"}]},{\"labels\":[{\"name\":\"__name__\",\"value\":\"MatchSeries\"},{\"name\":\"db\",\"value\":\"TenMinute\"},{\"name\":\"TurbineType\",\"value\":\"V112\"},{\"name\":\"Park\",\"value\":\"3\"}],\"samples\":[{\"value\":1,\"timestamp\":\"{TIME_MS}\"}]},{\"labels\":[{\"name\":\"__name__\",\"value\":\"MatchSeries\"},{\"name\":\"db\",\"value\":\"TenMinute\"},{\"name\":\"TurbineType\",\"value\":\"V112\"},{\"name\":\"Park\",\"value\":\"4\"}],\"samples\":[{\"value\":1,\"timestamp\":\"{TIME_MS}\"}]}]"],
+  "query": ["/api/v1/series?match[]={__name__='MatchSeries'}", "/api/v1/series?match[]={__name__=~'MatchSeries.*'}"],
+  "result_series": {
+    "status": "success",
+    "data": [
+      {"__name__":"MatchSeries","db":"TenMinute","Park":"1","TurbineType":"V112"},
+      {"__name__":"MatchSeries","db":"TenMinute","Park":"2","TurbineType":"V112"},
+      {"__name__":"MatchSeries","db":"TenMinute","Park":"3","TurbineType":"V112"},
+      {"__name__":"MatchSeries","db":"TenMinute","Park":"4","TurbineType":"V112"}
+    ]
+  }
+}

app/vminsert/graphite/parser_test.go

@@ -85,6 +85,15 @@ func TestRowsUnmarshalSuccess(t *testing.T) {
 		}},
 	})
 
+	// Timestamp bigger than 1<<31
+	f("aaa 1123 429496729600", &Rows{
+		Rows: []Row{{
+			Metric:    "aaa",
+			Value:     1123,
+			Timestamp: 429496729600,
+		}},
+	})
+
 	// Tags
 	f("foo;bar=baz 1 2", &Rows{
 		Rows: []Row{{

app/vminsert/opentsdbhttp/server.go

@@ -38,7 +38,7 @@ func Serve(addr string, maxReqSize int64) {
 			return
 		}
 		if err != nil {
-			logger.Fatalf("FATAL: error serving HTTP OpenTSDB: %s", err)
+			logger.Fatalf("error serving HTTP OpenTSDB: %s", err)
 		}
 	}()
 }
@@ -65,6 +65,6 @@ func Stop() {
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
 	if err := httpServer.Shutdown(ctx); err != nil {
-		logger.Fatalf("FATAL: cannot close HTTP OpenTSDB server: %s", err)
+		logger.Fatalf("cannot close HTTP OpenTSDB server: %s", err)
 	}
 }

app/vmselect/netstorage/fadvise_darwin.go

@@ -4,6 +4,6 @@ import (
 	"os"
 )
 
-func mustFadviseRandomRead(f *os.File) {
+func mustFadviseSequentialRead(f *os.File) {
 	// Do nothing :)
 }

app/vmselect/netstorage/fadvise_freebsd.go

@@ -7,9 +7,9 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-func mustFadviseRandomRead(f *os.File) {
+func mustFadviseSequentialRead(f *os.File) {
 	fd := int(f.Fd())
-	if err := unix.Fadvise(int(fd), 0, 0, unix.FADV_RANDOM|unix.FADV_WILLNEED); err != nil {
-		logger.Panicf("FATAL: error returned from unix.Fadvise(RANDOM|WILLNEED): %s", err)
+	if err := unix.Fadvise(int(fd), 0, 0, unix.FADV_SEQUENTIAL|unix.FADV_WILLNEED); err != nil {
+		logger.Panicf("FATAL: error returned from unix.Fadvise(SEQUENTIAL|WILLNEED): %s", err)
 	}
 }

app/vmselect/netstorage/fadvise_linux.go

@@ -7,9 +7,9 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-func mustFadviseRandomRead(f *os.File) {
+func mustFadviseSequentialRead(f *os.File) {
 	fd := int(f.Fd())
-	if err := unix.Fadvise(int(fd), 0, 0, unix.FADV_RANDOM|unix.FADV_WILLNEED); err != nil {
-		logger.Panicf("FATAL: error returned from unix.Fadvise(RANDOM|WILLNEED): %s", err)
+	if err := unix.Fadvise(int(fd), 0, 0, unix.FADV_SEQUENTIAL|unix.FADV_WILLNEED); err != nil {
+		logger.Panicf("FATAL: error returned from unix.Fadvise(SEQUENTIAL|WILLNEED): %s", err)
 	}
 }

app/vmselect/netstorage/netstorage.go

@@ -484,9 +484,12 @@ func ProcessSearchQuery(sq *storage.SearchQuery, fetchData bool, deadline Deadli
 	tbf := getTmpBlocksFile()
 	m := make(map[string][]tmpBlockAddr)
 	blocksRead := 0
+	bb := tmpBufPool.Get()
+	defer tmpBufPool.Put(bb)
 	for sr.NextMetricBlock() {
 		blocksRead++
-		addr, err := tbf.WriteBlock(sr.MetricBlock.Block)
+		bb.B = storage.MarshalBlock(bb.B[:0], sr.MetricBlock.Block)
+		addr, err := tbf.WriteBlockData(bb.B)
 		if err != nil {
 			putTmpBlocksFile(tbf)
 			return nil, fmt.Errorf("cannot write data block #%d to temporary blocks file: %s", blocksRead, err)
@@ -520,6 +523,15 @@ func ProcessSearchQuery(sq *storage.SearchQuery, fetchData bool, deadline Deadli
 		pts.metricName = metricName
 		pts.addrs = addrs
 	}
+
+	// Sort rss.packedTimeseries by the first addr offset in order
+	// to reduce the number of disk seeks during unpacking in RunParallel.
+	// In this case tmpBlocksFile must be read almost sequentially.
+	sort.Slice(rss.packedTimeseries, func(i, j int) bool {
+		pts := rss.packedTimeseries
+		return pts[i].addrs[0].offset < pts[j].addrs[0].offset
+	})
+
 	return &rss, nil
 }
 

app/vmselect/netstorage/tmp_blocks_file.go

@@ -82,22 +82,18 @@ func (addr tmpBlockAddr) String() string {
 
 var tmpBlocksFilesCreated = metrics.NewCounter(`vm_tmp_blocks_files_created_total`)
 
-// WriteBlock writes b to tbf.
+// WriteBlockData writes b to tbf.
 //
 // It returns errors since the operation may fail on space shortage
 // and this must be handled.
-func (tbf *tmpBlocksFile) WriteBlock(b *storage.Block) (tmpBlockAddr, error) {
-	bb := tmpBufPool.Get()
-	defer tmpBufPool.Put(bb)
-	bb.B = storage.MarshalBlock(bb.B[:0], b)
-
+func (tbf *tmpBlocksFile) WriteBlockData(b []byte) (tmpBlockAddr, error) {
 	var addr tmpBlockAddr
 	addr.offset = tbf.offset
-	addr.size = len(bb.B)
+	addr.size = len(b)
 	tbf.offset += uint64(addr.size)
-	if len(tbf.buf)+len(bb.B) <= cap(tbf.buf) {
+	if len(tbf.buf)+len(b) <= cap(tbf.buf) {
 		// Fast path - the data fits tbf.buf
-		tbf.buf = append(tbf.buf, bb.B...)
+		tbf.buf = append(tbf.buf, b...)
 		return addr, nil
 	}
 
@@ -111,7 +107,7 @@ func (tbf *tmpBlocksFile) WriteBlock(b *storage.Block) (tmpBlockAddr, error) {
 		tmpBlocksFilesCreated.Inc()
 	}
 	_, err := tbf.f.Write(tbf.buf)
-	tbf.buf = append(tbf.buf[:0], bb.B...)
+	tbf.buf = append(tbf.buf[:0], b...)
 	if err != nil {
 		return addr, fmt.Errorf("cannot write block to %q: %s", tbf.f.Name(), err)
 	}
@@ -129,7 +125,10 @@ func (tbf *tmpBlocksFile) Finalize() error {
 	if _, err := tbf.f.Seek(0, 0); err != nil {
 		logger.Panicf("FATAL: cannot seek to the start of file: %s", err)
 	}
-	mustFadviseRandomRead(tbf.f)
+	// Hint the OS that the file is read almost sequentiallly.
+	// This should reduce the number of disk seeks, which is important
+	// for HDDs.
+	mustFadviseSequentialRead(tbf.f)
 	return nil
 }
 

app/vmselect/netstorage/tmp_blocks_file_test.go

@@ -77,9 +77,12 @@ func testTmpBlocksFile() error {
 			// Write blocks until their summary size exceeds `size`.
 			var addrs []tmpBlockAddr
 			var blocks []*storage.Block
+			bb := tmpBufPool.Get()
+			defer tmpBufPool.Put(bb)
 			for tbf.offset < uint64(size) {
 				b := createBlock()
-				addr, err := tbf.WriteBlock(b)
+				bb.B = storage.MarshalBlock(bb.B[:0], b)
+				addr, err := tbf.WriteBlockData(bb.B)
 				if err != nil {
 					return fmt.Errorf("cannot write block at offset %d: %s", tbf.offset, err)
 				}

app/vmselect/prometheus/export.qtpl

@@ -13,7 +13,7 @@
 	{% for i, ts := range rs.Timestamps %}
 		{%z= bb.B %}{% space %}
 		{%f= rs.Values[i] %}{% space %}
-		{%d= int(ts) %}{% newline %}
+		{%dl= ts %}{% newline %}
 	{% endfor %}
 	{% code quicktemplate.ReleaseByteBuffer(bb) %}
 {% endfunc %}
@@ -35,10 +35,10 @@
 		"timestamps":[
 			{% if len(rs.Timestamps) > 0 %}
 				{% code timestamps := rs.Timestamps %}
-				{%d= int(timestamps[0]) %}
+				{%dl= timestamps[0] %}
 				{% code timestamps = timestamps[1:] %}
 				{% for _, ts := range timestamps %}
-					,{%d= int(ts) %}
+					,{%dl= ts %}
 				{% endfor %}
 			{% endif %}
 		]

app/vmselect/prometheus/export.qtpl.go

@@ -49,7 +49,7 @@ func StreamExportPrometheusLine(qw422016 *qt422016.Writer, rs *netstorage.Result
 //line app/vmselect/prometheus/export.qtpl:15
 		qw422016.N().S(` `)
 //line app/vmselect/prometheus/export.qtpl:16
-		qw422016.N().D(int(ts))
+		qw422016.N().DL(ts)
 //line app/vmselect/prometheus/export.qtpl:16
 		qw422016.N().S(`
 `)
@@ -129,7 +129,7 @@ func StreamExportJSONLine(qw422016 *qt422016.Writer, rs *netstorage.Result) {
 		timestamps := rs.Timestamps
 
 //line app/vmselect/prometheus/export.qtpl:38
-		qw422016.N().D(int(timestamps[0]))
+		qw422016.N().DL(timestamps[0])
 //line app/vmselect/prometheus/export.qtpl:39
 		timestamps = timestamps[1:]
 
@@ -138,7 +138,7 @@ func StreamExportJSONLine(qw422016 *qt422016.Writer, rs *netstorage.Result) {
 //line app/vmselect/prometheus/export.qtpl:40
 			qw422016.N().S(`,`)
 //line app/vmselect/prometheus/export.qtpl:41
-			qw422016.N().D(int(ts))
+			qw422016.N().DL(ts)
 //line app/vmselect/prometheus/export.qtpl:42
 		}
 //line app/vmselect/prometheus/export.qtpl:43

app/vmselect/prometheus/federate.qtpl

@@ -10,7 +10,7 @@
 	{% if len(rs.Timestamps) == 0 || len(rs.Values) == 0 %}{% return %}{% endif %}
 	{%= prometheusMetricName(&rs.MetricName) %}{% space %}
 	{%f= rs.Values[len(rs.Values)-1] %}{% space %}
-	{%d= int(rs.Timestamps[len(rs.Timestamps)-1]) %}{% newline %}
+	{%dl= rs.Timestamps[len(rs.Timestamps)-1] %}{% newline %}
 {% endfunc %}
 
 {% endstripspace %}

app/vmselect/prometheus/federate.qtpl.go

@@ -41,7 +41,7 @@ func StreamFederate(qw422016 *qt422016.Writer, rs *netstorage.Result) {
 //line app/vmselect/prometheus/federate.qtpl:12
 	qw422016.N().S(` `)
 //line app/vmselect/prometheus/federate.qtpl:13
-	qw422016.N().D(int(rs.Timestamps[len(rs.Timestamps)-1]))
+	qw422016.N().DL(rs.Timestamps[len(rs.Timestamps)-1])
 //line app/vmselect/prometheus/federate.qtpl:13
 	qw422016.N().S(`
 `)

app/vmselect/prometheus/prometheus.go

@@ -21,17 +21,17 @@ import (
 )
 
 var (
+	latencyOffset = flag.Duration("search.latencyOffset", time.Second*60, "The time when data points become visible in query results after the colection. "+
+		"Too small value can result in incomplete last points for query results")
 	maxQueryDuration = flag.Duration("search.maxQueryDuration", time.Second*30, "The maximum time for search query execution")
 	maxQueryLen      = flag.Int("search.maxQueryLen", 16*1024, "The maximum search query length in bytes")
+	maxLookback      = flag.Duration("search.maxLookback", 0, "Synonim to `-search.lookback-delta` from Prometheus. "+
+		"The value is dynamically detected from interval between time series datapoints if not set. It can be overriden on per-query basis via `max_lookback` arg")
 )
 
 // Default step used if not set.
 const defaultStep = 5 * 60 * 1000
 
-// Latency for data processing pipeline, i.e. the time between data is ignested
-// into the system and the time it becomes visible to search.
-const latencyOffset = 60 * 1000
-
 // FederateHandler implements /federate . See https://prometheus.io/docs/prometheus/latest/federation/
 func FederateHandler(w http.ResponseWriter, r *http.Request) error {
 	startTime := time.Now()
@@ -43,11 +43,14 @@ func FederateHandler(w http.ResponseWriter, r *http.Request) error {
 	if len(matches) == 0 {
 		return fmt.Errorf("missing `match[]` arg")
 	}
-	maxLookback, err := getDuration(r, "max_lookback", defaultStep)
+	lookbackDelta, err := getMaxLookback(r)
 	if err != nil {
 		return err
 	}
-	start, err := getTime(r, "start", ct-maxLookback)
+	if lookbackDelta <= 0 {
+		lookbackDelta = defaultStep
+	}
+	start, err := getTime(r, "start", ct-lookbackDelta)
 	if err != nil {
 		return err
 	}
@@ -463,17 +466,22 @@ func QueryHandler(w http.ResponseWriter, r *http.Request) error {
 	if err != nil {
 		return err
 	}
-	step, err := getDuration(r, "step", latencyOffset)
+	queryOffset := getLatencyOffsetMilliseconds()
+	step, err := getDuration(r, "step", queryOffset)
 	if err != nil {
 		return err
 	}
 	deadline := getDeadline(r)
+	lookbackDelta, err := getMaxLookback(r)
+	if err != nil {
+		return err
+	}
 
 	if len(query) > *maxQueryLen {
 		return fmt.Errorf(`too long query; got %d bytes; mustn't exceed %d bytes`, len(query), *maxQueryLen)
 	}
-	if ct-start < latencyOffset {
-		start -= latencyOffset
+	if ct-start < queryOffset {
+		start -= queryOffset
 	}
 	if childQuery, windowStr, offsetStr := promql.IsMetricSelectorWithRollup(query); childQuery != "" {
 		var window int64
@@ -503,10 +511,11 @@ func QueryHandler(w http.ResponseWriter, r *http.Request) error {
 	}
 
 	ec := promql.EvalConfig{
-		Start:    start,
-		End:      start,
-		Step:     step,
-		Deadline: deadline,
+		Start:         start,
+		End:           start,
+		Step:          step,
+		Deadline:      deadline,
+		LookbackDelta: lookbackDelta,
 	}
 	result, err := promql.Exec(&ec, query, true)
 	if err != nil {
@@ -546,6 +555,10 @@ func QueryRangeHandler(w http.ResponseWriter, r *http.Request) error {
 	}
 	deadline := getDeadline(r)
 	mayCache := !getBool(r, "nocache")
+	lookbackDelta, err := getMaxLookback(r)
+	if err != nil {
+		return err
+	}
 
 	// Validate input args.
 	if len(query) > *maxQueryLen {
@@ -562,17 +575,19 @@ func QueryRangeHandler(w http.ResponseWriter, r *http.Request) error {
 	}
 
 	ec := promql.EvalConfig{
-		Start:    start,
-		End:      end,
-		Step:     step,
-		Deadline: deadline,
-		MayCache: mayCache,
+		Start:         start,
+		End:           end,
+		Step:          step,
+		Deadline:      deadline,
+		MayCache:      mayCache,
+		LookbackDelta: lookbackDelta,
 	}
 	result, err := promql.Exec(&ec, query, false)
 	if err != nil {
 		return fmt.Errorf("cannot execute %q: %s", query, err)
 	}
-	if ct-end < latencyOffset {
+	queryOffset := getLatencyOffsetMilliseconds()
+	if ct-end < queryOffset {
 		result = adjustLastPoints(result)
 	}
 
@@ -726,6 +741,11 @@ func getDuration(r *http.Request, argKey string, defaultValue int64) (int64, err
 
 const maxDurationMsecs = 100 * 365 * 24 * 3600 * 1000
 
+func getMaxLookback(r *http.Request) (int64, error) {
+	d := int64(*maxLookback / time.Millisecond)
+	return getDuration(r, "max_lookback", d)
+}
+
 func getDeadline(r *http.Request) netstorage.Deadline {
 	d, err := getDuration(r, "timeout", 0)
 	if err != nil {
@@ -764,3 +784,11 @@ func getTagFilterssFromMatches(matches []string) ([][]storage.TagFilter, error)
 	}
 	return tagFilterss, nil
 }
+
+func getLatencyOffsetMilliseconds() int64 {
+	d := int64(*latencyOffset / time.Millisecond)
+	if d <= 1000 {
+		d = 1000
+	}
+	return d
+}

app/vmselect/prometheus/series_count_response.qtpl

@@ -3,7 +3,7 @@ SeriesCountResponse generates response for /api/v1/series/count .
 {% func SeriesCountResponse(n uint64) %}
 {
 	"status":"success",
-	"data":[{%d int(n) %}]
+	"data":[{%dl int64(n) %}]
 }
 {% endfunc %}
 {% endstripspace %}

app/vmselect/prometheus/series_count_response.qtpl.go

@@ -24,7 +24,7 @@ func StreamSeriesCountResponse(qw422016 *qt422016.Writer, n uint64) {
 //line app/vmselect/prometheus/series_count_response.qtpl:3
 	qw422016.N().S(`{"status":"success","data":[`)
 //line app/vmselect/prometheus/series_count_response.qtpl:6
-	qw422016.N().D(int(n))
+	qw422016.N().DL(int64(n))
 //line app/vmselect/prometheus/series_count_response.qtpl:6
 	qw422016.N().S(`]}`)
 //line app/vmselect/prometheus/series_count_response.qtpl:8

app/vmselect/promql/arch_386.go

@@ -0,0 +1,3 @@
+package promql
+
+const maxByteSliceLen = 1<<31 - 1

app/vmselect/promql/eval.go

@@ -70,6 +70,9 @@ type EvalConfig struct {
 
 	MayCache bool
 
+	// LookbackDelta is analog to `-query.lookback-delta` from Prometheus.
+	LookbackDelta int64
+
 	timestamps     []int64
 	timestampsOnce sync.Once
 }
@@ -82,6 +85,7 @@ func newEvalConfig(src *EvalConfig) *EvalConfig {
 	ec.Step = src.Step
 	ec.Deadline = src.Deadline
 	ec.MayCache = src.MayCache
+	ec.LookbackDelta = src.LookbackDelta
 
 	// do not copy src.timestamps - they must be generated again.
 	return &ec
@@ -465,7 +469,7 @@ func evalRollupFuncWithSubquery(ec *EvalConfig, name string, rf rollupFunc, re *
 	}
 
 	sharedTimestamps := getTimestamps(ec.Start, ec.End, ec.Step)
-	preFunc, rcs := getRollupConfigs(name, rf, ec.Start, ec.End, ec.Step, window, sharedTimestamps)
+	preFunc, rcs := getRollupConfigs(name, rf, ec.Start, ec.End, ec.Step, window, ec.LookbackDelta, sharedTimestamps)
 	tss := make([]*timeseries, 0, len(tssSQ)*len(rcs))
 	var tssLock sync.Mutex
 	removeMetricGroup := !rollupFuncsKeepMetricGroup[name]
@@ -586,7 +590,7 @@ func evalRollupFuncWithMetricExpr(ec *EvalConfig, name string, rf rollupFunc, me
 		return tss, nil
 	}
 	sharedTimestamps := getTimestamps(start, ec.End, ec.Step)
-	preFunc, rcs := getRollupConfigs(name, rf, start, ec.End, ec.Step, window, sharedTimestamps)
+	preFunc, rcs := getRollupConfigs(name, rf, start, ec.End, ec.Step, window, ec.LookbackDelta, sharedTimestamps)
 
 	// Verify timeseries fit available memory after the rollup.
 	// Take into account points from tssCached.
@@ -689,7 +693,8 @@ func doRollupForTimeseries(rc *rollupConfig, tsDst *timeseries, mnSrc *storage.M
 	tsDst.denyReuse = true
 }
 
-func getRollupConfigs(name string, rf rollupFunc, start, end, step, window int64, sharedTimestamps []int64) (func(values []float64, timestamps []int64), []*rollupConfig) {
+func getRollupConfigs(name string, rf rollupFunc, start, end, step, window int64, lookbackDelta int64, sharedTimestamps []int64) (
+	func(values []float64, timestamps []int64), []*rollupConfig) {
 	preFunc := func(values []float64, timestamps []int64) {}
 	if rollupFuncsRemoveCounterResets[name] {
 		preFunc = func(values []float64, timestamps []int64) {
@@ -705,6 +710,7 @@ func getRollupConfigs(name string, rf rollupFunc, start, end, step, window int64
 			Step:            step,
 			Window:          window,
 			MayAdjustWindow: rollupFuncsMayAdjustWindow[name],
+			LookbackDelta:   lookbackDelta,
 			Timestamps:      sharedTimestamps,
 		}
 	}

app/vmselect/promql/exec.go

@@ -194,11 +194,14 @@ type parseCacheValue struct {
 }
 
 type parseCache struct {
-	m  map[string]*parseCacheValue
-	mu sync.RWMutex
+	// Move atomic counters to the top of struct for 8-byte alignment on 32-bit arch.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212
 
 	requests uint64
 	misses   uint64
+
+	m  map[string]*parseCacheValue
+	mu sync.RWMutex
 }
 
 func (pc *parseCache) Requests() uint64 {

app/vmselect/promql/exec_test.go

@@ -369,6 +369,17 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run("timestamp(time()>=1600)", func(t *testing.T) {
+		t.Parallel()
+		q := `timestamp(time()>=1600)`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{nan, nan, nan, 1600, 1800, 2000},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
 	t.Run("time()/100", func(t *testing.T) {
 		t.Parallel()
 		q := `time()/100`
@@ -2671,6 +2682,28 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run(`increases_over_time`, func(t *testing.T) {
+		t.Parallel()
+		q := `increases_over_time(rand(0)[200s:10s])`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{11, 9, 9, 12, 9, 8},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
+	t.Run(`decreases_over_time`, func(t *testing.T) {
+		t.Parallel()
+		q := `decreases_over_time(rand(0)[200s:10s])`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{9, 11, 11, 8, 11, 12},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
 	t.Run(`limitk(-1)`, func(t *testing.T) {
 		t.Parallel()
 		q := `limitk(-1, label_set(10, "foo", "bar") or label_set(time()/150, "baz", "sss"))`
@@ -3523,7 +3556,7 @@ func TestExecSuccess(t *testing.T) {
 		}}
 		r4 := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{0.85, 0.94, 0.97, 0.93, 0.98, 0.92},
+			Values:     []float64{0.9, 0.94, 0.97, 0.93, 0.98, 0.92},
 			Timestamps: timestampsExpected,
 		}
 		r4.MetricName.Tags = []storage.Tag{{
@@ -3571,7 +3604,7 @@ func TestExecSuccess(t *testing.T) {
 		q := `sort(rollup(time()[:50s]))`
 		r1 := netstorage.Result{
 			MetricName: metricNameExpected,
-			Values:     []float64{850, 1050, 1250, 1450, 1650, 1850},
+			Values:     []float64{800, 1000, 1200, 1400, 1600, 1800},
 			Timestamps: timestampsExpected,
 		}
 		r1.MetricName.Tags = []storage.Tag{{
@@ -3677,6 +3710,17 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run(`lag()`, func(t *testing.T) {
+		t.Parallel()
+		q := `lag(time()[60s:17s])`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{14, 10, 6, 2, 15, 11},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
 	t.Run(`()`, func(t *testing.T) {
 		t.Parallel()
 		q := `()`
@@ -4142,6 +4186,8 @@ func TestExecError(t *testing.T) {
 	f(`alias()`)
 	f(`alias(1)`)
 	f(`alias(1, "foo", "bar")`)
+	f(`lifetime()`)
+	f(`lag()`)
 
 	// Invalid argument type
 	f(`median_over_time({}, 2)`)

app/vmselect/promql/regexp_cache.go

@@ -51,11 +51,14 @@ type regexpCacheValue struct {
 }
 
 type regexpCache struct {
-	m  map[string]*regexpCacheValue
-	mu sync.RWMutex
+	// Move atomic counters to the top of struct for 8-byte alignment on 32-bit arch.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212
 
 	requests uint64
 	misses   uint64
+
+	m  map[string]*regexpCacheValue
+	mu sync.RWMutex
 }
 
 func (rc *regexpCache) Requests() uint64 {

app/vmselect/promql/rollup.go

@@ -38,21 +38,24 @@ 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),
-	"integrate":          newRollupFuncOneArg(rollupIntegrate),
-	"ideriv":             newRollupFuncOneArg(rollupIderiv),
-	"lifetime":           newRollupFuncOneArg(rollupLifetime),
-	"scrape_interval":    newRollupFuncOneArg(rollupScrapeInterval),
-	"rollup":             newRollupFuncOneArg(rollupFake),
-	"rollup_rate":        newRollupFuncOneArg(rollupFake), // + rollupFuncsRemoveCounterResets
-	"rollup_deriv":       newRollupFuncOneArg(rollupFake),
-	"rollup_delta":       newRollupFuncOneArg(rollupFake),
-	"rollup_increase":    newRollupFuncOneArg(rollupFake), // + rollupFuncsRemoveCounterResets
-	"rollup_candlestick": newRollupFuncOneArg(rollupFake),
+	"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),
+	"increases_over_time": newRollupFuncOneArg(rollupIncreases),
+	"decreases_over_time": newRollupFuncOneArg(rollupDecreases),
+	"integrate":           newRollupFuncOneArg(rollupIntegrate),
+	"ideriv":              newRollupFuncOneArg(rollupIderiv),
+	"lifetime":            newRollupFuncOneArg(rollupLifetime),
+	"lag":                 newRollupFuncOneArg(rollupLag),
+	"scrape_interval":     newRollupFuncOneArg(rollupScrapeInterval),
+	"rollup":              newRollupFuncOneArg(rollupFake),
+	"rollup_rate":         newRollupFuncOneArg(rollupFake), // + rollupFuncsRemoveCounterResets
+	"rollup_deriv":        newRollupFuncOneArg(rollupFake),
+	"rollup_delta":        newRollupFuncOneArg(rollupFake),
+	"rollup_increase":     newRollupFuncOneArg(rollupFake), // + rollupFuncsRemoveCounterResets
+	"rollup_candlestick":  newRollupFuncOneArg(rollupFake),
 }
 
 var rollupFuncsMayAdjustWindow = map[string]bool{
@@ -111,8 +114,9 @@ type rollupFuncArg struct {
 	values        []float64
 	timestamps    []int64
 
-	idx  int
-	step int64
+	currTimestamp int64
+	idx           int
+	step          int64
 }
 
 func (rfa *rollupFuncArg) reset() {
@@ -120,6 +124,7 @@ func (rfa *rollupFuncArg) reset() {
 	rfa.prevTimestamp = 0
 	rfa.values = nil
 	rfa.timestamps = nil
+	rfa.currTimestamp = 0
 	rfa.idx = 0
 	rfa.step = 0
 }
@@ -147,6 +152,9 @@ type rollupConfig struct {
 	MayAdjustWindow bool
 
 	Timestamps []int64
+
+	// LoookbackDelta is the analog to `-query.lookback-delta` from Prometheus world.
+	LookbackDelta int64
 }
 
 var (
@@ -184,6 +192,9 @@ func (rc *rollupConfig) Do(dstValues []float64, values []float64, timestamps []i
 	dstValues = decimal.ExtendFloat64sCapacity(dstValues, len(rc.Timestamps))
 
 	maxPrevInterval := getMaxPrevInterval(timestamps)
+	if rc.LookbackDelta > 0 && maxPrevInterval > rc.LookbackDelta {
+		maxPrevInterval = rc.LookbackDelta
+	}
 	window := rc.Window
 	if window <= 0 {
 		window = rc.Step
@@ -218,6 +229,7 @@ func (rc *rollupConfig) Do(dstValues []float64, values []float64, timestamps []i
 
 		rfa.values = values[i:j]
 		rfa.timestamps = timestamps[i:j]
+		rfa.currTimestamp = tEnd
 		value := rc.Func(rfa)
 		rfa.idx++
 		dstValues = append(dstValues, value)
@@ -531,11 +543,14 @@ func rollupAvg(rfa *rollupFuncArg) float64 {
 func rollupMin(rfa *rollupFuncArg) float64 {
 	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
+	minValue := rfa.prevValue
 	values := rfa.values
-	if len(values) == 0 {
-		return rfa.prevValue
+	if math.IsNaN(minValue) {
+		if len(values) == 0 {
+			return nan
+		}
+		minValue = values[0]
 	}
-	minValue := values[0]
 	for _, v := range values {
 		if v < minValue {
 			minValue = v
@@ -547,11 +562,14 @@ func rollupMin(rfa *rollupFuncArg) float64 {
 func rollupMax(rfa *rollupFuncArg) float64 {
 	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.
+	maxValue := rfa.prevValue
 	values := rfa.values
-	if len(values) == 0 {
-		return rfa.prevValue
+	if math.IsNaN(maxValue) {
+		if len(values) == 0 {
+			return nan
+		}
+		maxValue = values[0]
 	}
-	maxValue := values[0]
 	for _, v := range values {
 		if v > maxValue {
 			maxValue = v
@@ -565,7 +583,10 @@ func rollupSum(rfa *rollupFuncArg) float64 {
 	// before calling rollup funcs.
 	values := rfa.values
 	if len(values) == 0 {
-		return rfa.prevValue
+		if math.IsNaN(rfa.prevValue) {
+			return nan
+		}
+		return 0
 	}
 	var sum float64
 	for _, v := range values {
@@ -782,6 +803,18 @@ func rollupLifetime(rfa *rollupFuncArg) float64 {
 	return float64(timestamps[len(timestamps)-1]-rfa.prevTimestamp) * 1e-3
 }
 
+func rollupLag(rfa *rollupFuncArg) float64 {
+	// Calculate the duration between the current timestamp and the last data point.
+	timestamps := rfa.timestamps
+	if len(timestamps) == 0 {
+		if math.IsNaN(rfa.prevValue) {
+			return nan
+		}
+		return float64(rfa.currTimestamp-rfa.prevTimestamp) * 1e-3
+	}
+	return float64(rfa.currTimestamp-timestamps[len(timestamps)-1]) * 1e-3
+}
+
 func rollupScrapeInterval(rfa *rollupFuncArg) float64 {
 	// Calculate the average interval between data points.
 	timestamps := rfa.timestamps
@@ -820,6 +853,37 @@ func rollupChanges(rfa *rollupFuncArg) float64 {
 	return float64(n)
 }
 
+func rollupIncreases(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
+	}
+	prevValue := rfa.prevValue
+	if math.IsNaN(prevValue) {
+		prevValue = values[0]
+		values = values[1:]
+	}
+	if len(values) == 0 {
+		return 0
+	}
+	n := 0
+	for _, v := range values {
+		if v > prevValue {
+			n++
+		}
+		prevValue = v
+	}
+	return float64(n)
+}
+
+// `decreases_over_time` logic is the same as `resets` logic.
+var rollupDecreases = rollupResets
+
 func rollupResets(rfa *rollupFuncArg) float64 {
 	// There is no need in handling NaNs here, since they must be cleaned up
 	// before calling rollup funcs.

app/vmselect/promql/rollup_test.go

@@ -294,6 +294,8 @@ func TestRollupNewRollupFuncSuccess(t *testing.T) {
 	f("integrate", 61.0275)
 	f("distinct_over_time", 8)
 	f("ideriv", 0)
+	f("decreases_over_time", 5)
+	f("increases_over_time", 5)
 }
 
 func TestRollupNewRollupFuncError(t *testing.T) {
@@ -486,6 +488,51 @@ func TestRollupWindowPartialPoints(t *testing.T) {
 	})
 }
 
+func TestRollupFuncsLookbackDelta(t *testing.T) {
+	t.Run("1", func(t *testing.T) {
+		rc := rollupConfig{
+			Func:          rollupFirst,
+			Start:         80,
+			End:           140,
+			Step:          10,
+			LookbackDelta: 1,
+		}
+		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
+		values := rc.Do(nil, testValues, testTimestamps)
+		valuesExpected := []float64{99, 12, 44, nan, 32, 34, nan}
+		timestampsExpected := []int64{80, 90, 100, 110, 120, 130, 140}
+		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
+	})
+	t.Run("7", func(t *testing.T) {
+		rc := rollupConfig{
+			Func:          rollupFirst,
+			Start:         80,
+			End:           140,
+			Step:          10,
+			LookbackDelta: 7,
+		}
+		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
+		values := rc.Do(nil, testValues, testTimestamps)
+		valuesExpected := []float64{99, 12, 44, 44, 32, 34, nan}
+		timestampsExpected := []int64{80, 90, 100, 110, 120, 130, 140}
+		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
+	})
+	t.Run("0", func(t *testing.T) {
+		rc := rollupConfig{
+			Func:          rollupFirst,
+			Start:         80,
+			End:           140,
+			Step:          10,
+			LookbackDelta: 0,
+		}
+		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
+		values := rc.Do(nil, testValues, testTimestamps)
+		valuesExpected := []float64{34, 12, 12, 44, 44, 34, nan}
+		timestampsExpected := []int64{80, 90, 100, 110, 120, 130, 140}
+		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
+	})
+}
+
 func TestRollupFuncsNoWindow(t *testing.T) {
 	t.Run("first", func(t *testing.T) {
 		rc := rollupConfig{
@@ -525,7 +572,7 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		}
 		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
 		values := rc.Do(nil, testValues, testTimestamps)
-		valuesExpected := []float64{nan, 21, 12, 32, 34}
+		valuesExpected := []float64{nan, 21, 12, 12, 34}
 		timestampsExpected := []int64{0, 40, 80, 120, 160}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
@@ -585,6 +632,20 @@ func TestRollupFuncsNoWindow(t *testing.T) {
 		timestampsExpected := []int64{10, 50, 90, 130}
 		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
 	})
+	t.Run("lag", func(t *testing.T) {
+		rc := rollupConfig{
+			Func:   rollupLag,
+			Start:  0,
+			End:    160,
+			Step:   40,
+			Window: 0,
+		}
+		rc.Timestamps = getTimestamps(rc.Start, rc.End, rc.Step)
+		values := rc.Do(nil, testValues, testTimestamps)
+		valuesExpected := []float64{nan, 0.004, 0, 0, 0.03}
+		timestampsExpected := []int64{0, 40, 80, 120, 160}
+		testRowsEqual(t, values, rc.Timestamps, valuesExpected, timestampsExpected)
+	})
 	t.Run("lifetime_1", func(t *testing.T) {
 		rc := rollupConfig{
 			Func:   rollupLifetime,
@@ -811,7 +872,7 @@ func testRowsEqual(t *testing.T, values []float64, timestamps []int64, valuesExp
 			}
 			continue
 		}
-		if v != vExpected {
+		if math.Abs(v-vExpected) > 1e-15 {
 			t.Fatalf("unexpected value at values[%d]; got %f; want %f\nvalues=\n%v\nvaluesExpected=\n%v",
 				i, v, vExpected, values, valuesExpected)
 		}

app/vmselect/promql/transform.go

@@ -1121,7 +1121,10 @@ func transformTimestamp(tfa *transformFuncArg) ([]*timeseries, error) {
 		ts.MetricName.ResetMetricGroup()
 		values := ts.Values
 		for i, t := range ts.Timestamps {
-			values[i] = float64(t) / 1e3
+			v := values[i]
+			if !math.IsNaN(v) {
+				values[i] = float64(t) / 1e3
+			}
 		}
 	}
 	return rvs, nil

app/vmstorage/main.go

@@ -24,6 +24,9 @@ var (
 
 	// DataPath is a path to storage data.
 	DataPath = flag.String("storageDataPath", "victoria-metrics-data", "Path to storage data")
+
+	bigMergeConcurrency   = flag.Int("bigMergeConcurrency", 0, "The maximum number of CPU cores to use for big merges. Default value is used if set to 0")
+	smallMergeConcurrency = flag.Int("smallMergeConcurrency", 0, "The maximum number of CPU cores to use for small merges. Default value is used if set to 0")
 )
 
 // Init initializes vmstorage.
@@ -39,6 +42,10 @@ func InitWithoutMetrics() {
 	if err := encoding.CheckPrecisionBits(uint8(*precisionBits)); err != nil {
 		logger.Fatalf("invalid `-precisionBits`: %s", err)
 	}
+
+	storage.SetBigMergeWorkersCount(*bigMergeConcurrency)
+	storage.SetSmallMergeWorkersCount(*smallMergeConcurrency)
+
 	logger.Infof("opening storage at %q with retention period %d months", *DataPath, *retentionPeriod)
 	startTime := time.Now()
 	WG = syncwg.WaitGroup{}

dashboards/victoriametrics.json

@@ -14,7 +14,7 @@
       "type": "grafana",
       "id": "grafana",
       "name": "Grafana",
-      "version": "6.2.1"
+      "version": "6.3.5"
     },
     {
       "type": "panel",
@@ -60,12 +60,12 @@
       }
     ]
   },
-  "description": "Overview for single node VictoriaMetrics v1.22.2 or higher",
+  "description": "Overview for single node VictoriaMetrics v1.28.0 or higher",
   "editable": true,
   "gnetId": 10229,
   "graphTooltip": 0,
   "id": null,
-  "iteration": 1563651131627,
+  "iteration": 1572208904768,
   "links": [
     {
       "icon": "doc",
@@ -121,7 +121,6 @@
         {
           "targetBlank": true,
           "title": "VictoriaMetrics releases",
-          "type": "absolute",
           "url": "https://github.com/VictoriaMetrics/VictoriaMetrics/releases"
         }
       ],
@@ -490,6 +489,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "* `*` - unsupported query path\n* `/write` - insert into VM\n* `/metrics` - query VM system metrics\n* `/query` - query instant values\n* `/query_range` - query over a range of time\n* `/series` - match a certain label set\n* `/label/{}/values` - query a list of label values (variables mostly)",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -513,7 +513,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null as zero",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -580,6 +582,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "The less time it takes is better.\n* `*` - unsupported query path\n* `/write` - insert into VM\n* `/metrics` - query VM system metrics\n* `/query` - query instant values\n* `/query_range` - query over a range of time\n* `/series` - match a certain label set\n* `/label/{}/values` - query a list of label values (variables mostly)",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -603,7 +606,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null as zero",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -670,6 +675,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "Shows the number of active time series with new data points inserted during the last hour. High value may result in ingestion slowdown. \n\nSee following link for details:",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -692,12 +698,13 @@
         {
           "targetBlank": true,
           "title": "troubleshooting",
-          "type": "absolute",
           "url": "https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#troubleshooting"
         }
       ],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -764,6 +771,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "VictoriaMetrics stores various caches in RAM. Memory size for these caches may be limited with -`memory.allowedPercent` flag. Line `max allowed` shows max allowed memory size for cache.",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -784,7 +792,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -865,6 +875,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "* `*` - unsupported query path\n* `/write` - insert into VM\n* `/metrics` - query VM system metrics\n* `/query` - query instant values\n* `/query_range` - query over a range of time\n* `/series` - match a certain label set\n* `/label/{}/values` - query a list of label values (variables mostly)",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -888,7 +899,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null as zero",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -953,55 +966,74 @@
       "dashLength": 10,
       "dashes": false,
       "datasource": "${DS_PROMETHEUS}",
-      "description": "",
+      "description": "Shows how many ongoing insertions are taking place.\n* `max` - equal to number of CPU * 2\n* `current` - current number of goroutines busy with inserting rows into storage\n\nWhen `current` hits `max` constantly, it means storage is overloaded and require more CPU.",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
         "x": 12,
         "y": 27
       },
-      "id": 49,
+      "id": 59,
       "legend": {
-        "avg": false,
-        "current": false,
+        "alignAsTable": true,
+        "avg": true,
+        "current": true,
+        "hideEmpty": false,
+        "hideZero": false,
         "max": false,
         "min": false,
-        "show": false,
+        "show": true,
+        "sort": "current",
+        "sortDesc": true,
         "total": false,
-        "values": false
+        "values": true
       },
       "lines": true,
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
       "renderer": "flot",
-      "seriesOverrides": [],
+      "seriesOverrides": [
+        {
+          "alias": "max",
+          "color": "#C4162A"
+        }
+      ],
       "spaceLength": 10,
       "stack": false,
       "steppedLine": false,
       "targets": [
         {
-          "expr": "sum(rate(vm_tcplistener_accepts_total{job=\"$job\"}[$__interval]))",
+          "expr": "sum(vm_concurrent_addrows_capacity{job=\"$job\"})",
           "format": "time_series",
-          "hide": false,
           "intervalFactor": 1,
-          "legendFormat": "connections",
+          "legendFormat": "max",
           "refId": "A"
+        },
+        {
+          "expr": "sum(vm_concurrent_addrows_current{job=\"$job\"})",
+          "format": "time_series",
+          "intervalFactor": 1,
+          "legendFormat": "current",
+          "refId": "B"
         }
       ],
       "thresholds": [],
       "timeFrom": null,
       "timeRegions": [],
       "timeShift": null,
-      "title": "TCP connections rate",
+      "title": "Concurrent inserts",
       "tooltip": {
         "shared": true,
-        "sort": 0,
+        "sort": 2,
         "value_type": "individual"
       },
       "type": "graph",
@@ -1014,7 +1046,7 @@
       },
       "yaxes": [
         {
-          "decimals": null,
+          "decimals": 0,
           "format": "short",
           "label": null,
           "logBase": 1,
@@ -1023,6 +1055,7 @@
           "show": true
         },
         {
+          "decimals": 0,
           "format": "short",
           "label": null,
           "logBase": 1,
@@ -1044,6 +1077,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -1064,7 +1098,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -1125,6 +1161,98 @@
         "alignLevel": null
       }
     },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": "${DS_PROMETHEUS}",
+      "description": "",
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 12,
+        "y": 35
+      },
+      "id": 49,
+      "legend": {
+        "avg": false,
+        "current": false,
+        "max": false,
+        "min": false,
+        "show": false,
+        "total": false,
+        "values": false
+      },
+      "lines": true,
+      "linewidth": 1,
+      "links": [],
+      "nullPointMode": "null",
+      "options": {
+        "dataLinks": []
+      },
+      "percentage": false,
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "expr": "sum(rate(vm_tcplistener_accepts_total{job=\"$job\"}[$__interval]))",
+          "format": "time_series",
+          "hide": false,
+          "intervalFactor": 1,
+          "legendFormat": "connections",
+          "refId": "A"
+        }
+      ],
+      "thresholds": [],
+      "timeFrom": null,
+      "timeRegions": [],
+      "timeShift": null,
+      "title": "TCP connections rate",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "buckets": null,
+        "mode": "time",
+        "name": null,
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "decimals": null,
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        },
+        {
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false,
+        "alignLevel": null
+      }
+    },
     {
       "collapsed": false,
       "gridPos": {
@@ -1146,6 +1274,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "How many datapoints are inserted into storage per second",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -1168,7 +1297,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null as zero",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -1242,6 +1373,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "How many datapoints are in RAM queue waiting to be written into storage. The less is better.",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -1262,7 +1394,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -1344,6 +1478,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "How many datapoints are in the storage.",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -1364,7 +1499,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -1431,6 +1568,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "Data parts of LSM tree.\nHigh number of parts could be an evidence of slow merge performance - check the resource utilization.\n* `indexdb` - inverted index\n* `storage/small` - recently added parts of data ingested into storage(hot data)\n* `storage/big` -  small parts gradually merged into big parts (cold data)",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -1451,7 +1589,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -1518,6 +1658,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "Shows amount of on-disk space occupied by data points.",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -1538,7 +1679,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -1605,6 +1748,7 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "Shows amount of on-disk space occupied by inverted index.",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
@@ -1625,7 +1769,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -1683,13 +1829,105 @@
         "alignLevel": null
       }
     },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": "${DS_PROMETHEUS}",
+      "description": "Shows how many rows were ignored on insertion due to corrupted or out of retention timestamps.",
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 0,
+        "y": 68
+      },
+      "id": 58,
+      "legend": {
+        "avg": false,
+        "current": false,
+        "max": false,
+        "min": false,
+        "show": false,
+        "total": false,
+        "values": false
+      },
+      "lines": true,
+      "linewidth": 1,
+      "links": [],
+      "nullPointMode": "null",
+      "options": {
+        "dataLinks": []
+      },
+      "percentage": false,
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "expr": "sum(vm_rows_ignored_total{job=\"$job\"}) by (reason) > 0",
+          "format": "time_series",
+          "hide": false,
+          "intervalFactor": 1,
+          "legendFormat": "{{reason}}",
+          "refId": "A"
+        }
+      ],
+      "thresholds": [],
+      "timeFrom": null,
+      "timeRegions": [],
+      "timeShift": null,
+      "title": "Rows ignored",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "buckets": null,
+        "mode": "time",
+        "name": null,
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "decimals": null,
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        },
+        {
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false,
+        "alignLevel": null
+      }
+    },
     {
       "collapsed": false,
       "gridPos": {
         "h": 1,
         "w": 24,
         "x": 0,
-        "y": 68
+        "y": 76
       },
       "id": 46,
       "panels": [],
@@ -1704,11 +1942,12 @@
       "datasource": "${DS_PROMETHEUS}",
       "description": "",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
         "x": 0,
-        "y": 69
+        "y": 77
       },
       "id": 44,
       "legend": {
@@ -1724,7 +1963,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -1806,11 +2047,12 @@
       "dashLength": 10,
       "dashes": false,
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
         "x": 12,
-        "y": 69
+        "y": 77
       },
       "id": 57,
       "legend": {
@@ -1826,7 +2068,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -1892,11 +2136,12 @@
       "dashes": false,
       "datasource": "${DS_PROMETHEUS}",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
         "x": 0,
-        "y": 77
+        "y": 85
       },
       "id": 47,
       "legend": {
@@ -1912,7 +2157,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -1979,11 +2226,12 @@
       "dashes": false,
       "datasource": "${DS_PROMETHEUS}",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
         "x": 12,
-        "y": 77
+        "y": 85
       },
       "id": 42,
       "legend": {
@@ -1999,7 +2247,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -2065,11 +2315,12 @@
       "dashes": false,
       "datasource": "${DS_PROMETHEUS}",
       "fill": 1,
+      "fillGradient": 0,
       "gridPos": {
         "h": 8,
         "w": 12,
         "x": 0,
-        "y": 85
+        "y": 93
       },
       "id": 48,
       "legend": {
@@ -2085,7 +2336,9 @@
       "linewidth": 1,
       "links": [],
       "nullPointMode": "null",
-      "options": {},
+      "options": {
+        "dataLinks": []
+      },
       "percentage": false,
       "pointradius": 2,
       "points": false,
@@ -2147,7 +2400,7 @@
     }
   ],
   "refresh": "30s",
-  "schemaVersion": 18,
+  "schemaVersion": 19,
   "style": "dark",
   "tags": [],
   "templating": {
@@ -2230,5 +2483,5 @@
   "timezone": "",
   "title": "VictoriaMetrics",
   "uid": "wNf0q_kZk",
-  "version": 2
-}
+  "version": 3
+}

deployment/docker/Makefile

@@ -1,5 +1,5 @@
 DOCKER_NAMESPACE := victoriametrics
-BUILDER_IMAGE := local/builder:go1.13.0
+BUILDER_IMAGE := local/builder:go1.13.3
 CERTS_IMAGE := local/certs:1.0.2
 
 package-certs:

deployment/docker/builder/Dockerfile

@@ -1,2 +1,2 @@
-FROM golang:1.13.0
+FROM golang:1.13.3
 STOPSIGNAL SIGINT

deployment/docker/docker-compose.yml

@@ -2,7 +2,7 @@ version: '3.5'
 services:
   prometheus:
     container_name: prometheus
-    image: prom/prometheus:v2.10.0
+    image: prom/prometheus:v2.12.0
     depends_on:
       - "victoriametrics"
     ports:
@@ -35,7 +35,7 @@ services:
     restart: always
   grafana:
     container_name: grafana
-    image: grafana/grafana:6.2.1
+    image: grafana/grafana:6.3.5
     entrypoint: >
       /bin/sh -c "
       cd /var/lib/grafana &&

go.mod

@@ -1,17 +1,18 @@
 module github.com/VictoriaMetrics/VictoriaMetrics
 
 require (
-	github.com/VictoriaMetrics/fastcache v1.5.1
-	github.com/VictoriaMetrics/metrics v1.7.1
+	github.com/VictoriaMetrics/fastcache v1.5.2
+	github.com/VictoriaMetrics/metrics v1.7.2
 	github.com/cespare/xxhash/v2 v2.1.0
 	github.com/golang/snappy v0.0.1
 	github.com/google/go-cmp v0.3.0 // indirect
-	github.com/klauspost/compress v1.8.3
+	github.com/klauspost/compress v1.9.1
 	github.com/valyala/fastjson v1.4.1
-	github.com/valyala/gozstd v1.6.1
+	github.com/valyala/fastrand v1.0.0
+	github.com/valyala/gozstd v1.6.2
 	github.com/valyala/histogram v1.0.1
-	github.com/valyala/quicktemplate v1.2.0
-	golang.org/x/sys v0.0.0-20190913121621-c3b328c6e5a7
+	github.com/valyala/quicktemplate v1.3.1
+	golang.org/x/sys v0.0.0-20191027211539-f8518d3b3627
 )
 
 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 v1.5.1 h1:qHgHjyoNFV7jgucU8QZUuU4gcdhfs8QW1kw68OD2Lag=
-github.com/VictoriaMetrics/fastcache v1.5.1/go.mod h1:+jv9Ckb+za/P1ZRg/sulP5Ni1v49daAVERr0H3CuscE=
-github.com/VictoriaMetrics/metrics v1.7.1 h1:g2qrY6Upn8rvlvR40cGHFY0crwi4hpqF0n9vJMNsCSg=
-github.com/VictoriaMetrics/metrics v1.7.1/go.mod h1:LU2j9qq7xqZYXz8tF3/RQnB2z2MbZms5TDiIg9/NHiQ=
+github.com/VictoriaMetrics/fastcache v1.5.2 h1:Erd8iIuBAL9kke8JzM4+WxkKuFkHh3ktwLanJvDgR44=
+github.com/VictoriaMetrics/fastcache v1.5.2/go.mod h1:+jv9Ckb+za/P1ZRg/sulP5Ni1v49daAVERr0H3CuscE=
+github.com/VictoriaMetrics/metrics v1.7.2 h1:PzC0SEo5lbbNK7xaYwclCCdoaIGRmXOfflIMF3LpSW4=
+github.com/VictoriaMetrics/metrics v1.7.2/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=
@@ -22,8 +22,8 @@ github.com/google/go-cmp v0.3.0 h1:crn/baboCvb5fXaQ0IJ1SGTsTVrWpDsCWC8EGETZijY=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/klauspost/compress v1.4.0/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
 github.com/klauspost/compress v1.4.1/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
-github.com/klauspost/compress v1.8.3 h1:CkLseiEYMM/fRb0RIg9mXB+Iwgmle+U9KGFu+JCO4Ec=
-github.com/klauspost/compress v1.8.3/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
+github.com/klauspost/compress v1.9.1 h1:TWy0o9J9c6LK9C8t7Msh6IAJNXbsU/nvKLTQUU5HdaY=
+github.com/klauspost/compress v1.9.1/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
 github.com/klauspost/cpuid v0.0.0-20180405133222-e7e905edc00e/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
 github.com/klauspost/cpuid v1.2.0 h1:NMpwD2G9JSFOE1/TJjGSo5zG7Yb2bTe7eq1jH+irmeE=
 github.com/klauspost/cpuid v1.2.0/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
@@ -41,13 +41,13 @@ 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 v1.6.1 h1:oFN2mNW0kOr1fEKJuLpDwakNb6Y9fElVEBZmPEsFTUw=
-github.com/valyala/gozstd v1.6.1/go.mod h1:y5Ew47GLlP37EkTB+B4s7r6A5rdaeB7ftbl9zoYiIPQ=
+github.com/valyala/gozstd v1.6.2 h1:MgBfNm0I8IKm51LUTTKfO9vi4BtmoH7kBXeUvgaiZVU=
+github.com/valyala/gozstd v1.6.2/go.mod h1:y5Ew47GLlP37EkTB+B4s7r6A5rdaeB7ftbl9zoYiIPQ=
 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 v1.2.0 h1:BaO1nHTkspYzmAjPXj0QiDJxai96tlcZyKcI9dyEGvM=
-github.com/valyala/quicktemplate v1.2.0/go.mod h1:EH+4AkTd43SvgIbQHYu59/cJyxDoOVRUAfrukLPuGJ4=
+github.com/valyala/quicktemplate v1.3.1 h1:V9Ixd/ONuoT6C1ipx8XR2dNGSDgIVnvT4ezZ38ZWllU=
+github.com/valyala/quicktemplate v1.3.1/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 v0.0.0-20190913121621-c3b328c6e5a7 h1:wYqz/tQaWUgGKyx+B/rssSE6wkIKdY5Ee6ryOmzarIg=
-golang.org/x/sys v0.0.0-20190913121621-c3b328c6e5a7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191027211539-f8518d3b3627 h1:/FZUR3d/QsXe4AcJyJFCc40TOj3y6Hs23Y3YJlvVkWo=
+golang.org/x/sys v0.0.0-20191027211539-f8518d3b3627/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

lib/bytesutil/bytesutil_test.go

@@ -1,6 +1,7 @@
 package bytesutil
 
 import (
+	"bytes"
 	"testing"
 )
 
@@ -20,3 +21,10 @@ func TestResize(t *testing.T) {
 		}
 	}
 }
+
+func TestToUnsafeString(t *testing.T) {
+	s := "str"
+	if !bytes.Equal([]byte("str"), ToUnsafeBytes(s)) {
+		t.Fatalf(`[]bytes(%s) doesnt equal to %s `, s, s)
+	}
+}

lib/decimal/decimal.go

@@ -3,6 +3,8 @@ package decimal
 import (
 	"math"
 	"sync"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fastnum"
 )
 
 // CalibrateScale calibrates a and b with the corresponding exponents ae, be
@@ -81,6 +83,13 @@ func ExtendInt64sCapacity(dst []int64, additionalItems int) []int64 {
 // AppendDecimalToFloat converts each item in va to f=v*10^e, appends it
 // to dst and returns the resulting dst.
 func AppendDecimalToFloat(dst []float64, va []int64, e int16) []float64 {
+	if fastnum.IsInt64Zeros(va) {
+		return fastnum.AppendFloat64Zeros(dst, len(va))
+	}
+	if e == 0 && fastnum.IsInt64Ones(va) {
+		return fastnum.AppendFloat64Ones(dst, len(va))
+	}
+
 	// Extend dst capacity in order to eliminate memory allocations below.
 	dst = ExtendFloat64sCapacity(dst, len(va))
 
@@ -108,6 +117,14 @@ func AppendFloatToDecimal(dst []int64, src []float64) (va []int64, e int16) {
 	if len(src) == 0 {
 		return dst, 0
 	}
+	if fastnum.IsFloat64Zeros(src) {
+		dst = fastnum.AppendInt64Zeros(dst, len(src))
+		return dst, 0
+	}
+	if fastnum.IsFloat64Ones(src) {
+		dst = fastnum.AppendInt64Ones(dst, len(src))
+		return dst, 0
+	}
 
 	// Extend dst capacity in order to eliminate memory allocations below.
 	dst = ExtendInt64sCapacity(dst, len(src))
@@ -265,61 +282,83 @@ var (
 // For instance, for f = -1.234 it returns v = -1234, e = -3.
 //
 // FromFloat doesn't work properly with NaN values, so don't pass them here.
-func FromFloat(f float64) (v int64, e int16) {
-	if math.IsInf(f, 0) {
-		// Special case for Inf
-		if math.IsInf(f, 1) {
-			return vInfPos, 0
-		}
-		return vInfNeg, 0
-	}
-
-	minus := false
-	if f < 0 {
-		f = -f
-		minus = true
-	}
+func FromFloat(f float64) (int64, int16) {
 	if f == 0 {
-		// Special case for 0.0 and -0.0
 		return 0, 0
 	}
-	v, e = positiveFloatToDecimal(f)
-	if minus {
-		v = -v
+	if math.IsInf(f, 0) {
+		return fromFloatInf(f)
 	}
-	if v == 0 {
-		e = 0
-	} else if v > vMax {
-		v = vMax
-	} else if v < vMin {
+	if f > 0 {
+		v, e := positiveFloatToDecimal(f)
+		if v > vMax {
+			v = vMax
+		}
+		return v, e
+	}
+	v, e := positiveFloatToDecimal(-f)
+	v = -v
+	if v < vMin {
 		v = vMin
 	}
 	return v, e
 }
 
+func fromFloatInf(f float64) (int64, int16) {
+	// Special case for Inf
+	if math.IsInf(f, 1) {
+		return vInfPos, 0
+	}
+	return vInfNeg, 0
+}
+
 func positiveFloatToDecimal(f float64) (int64, int16) {
+	// There is no need in checking for f == 0, since it should be already checked by the caller.
+	u := uint64(f)
+	if float64(u) != f {
+		return positiveFloatToDecimalSlow(f)
+	}
+	// Fast path for integers.
+	if u < 1<<55 && u%10 != 0 {
+		return int64(u), 0
+	}
+	return getDecimalAndScale(u)
+}
+
+func getDecimalAndScale(u uint64) (int64, int16) {
 	var scale int16
-	v := int64(f)
-	if f == float64(v) {
-		// Fast path for integers.
-		u := uint64(v)
-		if u%10 != 0 {
-			return v, 0
-		}
-		// Minimize v by converting trailing zeros to scale.
+	for u >= 1<<55 {
+		// Remove trailing garbage bits left after float64->uint64 conversion,
+		// since float64 contains only 53 significant bits.
+		// See https://en.wikipedia.org/wiki/Double-precision_floating-point_format
 		u /= 10
 		scale++
-		for u != 0 && u%10 == 0 {
-			u /= 10
-			scale++
-		}
+	}
+	if u%10 != 0 {
 		return int64(u), scale
 	}
+	// Minimize v by converting trailing zeros to scale.
+	u /= 10
+	scale++
+	for u != 0 && u%10 == 0 {
+		u /= 10
+		scale++
+	}
+	return int64(u), scale
+}
 
+func positiveFloatToDecimalSlow(f float64) (int64, int16) {
 	// Slow path for floating point numbers.
+	var scale int16
+	prec := conversionPrecision
 	if f > 1e6 || f < 1e-6 {
 		// Normalize f, so it is in the small range suitable
 		// for the next loop.
+		if f > 1e6 {
+			// Increase conversion precision for big numbers.
+			// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/213
+			prec = 1e15
+		}
 		_, exp := math.Frexp(f)
 		scale = int16(float64(exp) * math.Ln2 / math.Ln10)
 		f *= math.Pow10(-int(scale))
@@ -327,13 +366,13 @@ func positiveFloatToDecimal(f float64) (int64, int16) {
 
 	// Multiply f by 100 until the fractional part becomes
 	// too small comparing to integer part.
-	for f < conversionPrecision {
+	for f < prec {
 		x, frac := math.Modf(f)
-		if frac*conversionPrecision < x {
+		if frac*prec < x {
 			f = x
 			break
 		}
-		if (1-frac)*conversionPrecision < x {
+		if (1-frac)*prec < x {
 			f = x + 1
 			break
 		}

lib/decimal/decimal_test.go

@@ -7,6 +7,44 @@ import (
 	"testing"
 )
 
+func TestPositiveFloatToDecimal(t *testing.T) {
+	f := func(f float64, decimalExpected int64, exponentExpected int16) {
+		t.Helper()
+		decimal, exponent := positiveFloatToDecimal(f)
+		if decimal != decimalExpected {
+			t.Fatalf("unexpected decimal for positiveFloatToDecimal(%f); got %d; want %d", f, decimal, decimalExpected)
+		}
+		if exponent != exponentExpected {
+			t.Fatalf("unexpected exponent for positiveFloatToDecimal(%f); got %d; want %d", f, exponent, exponentExpected)
+		}
+	}
+	f(0, 0, 1) // The exponent is 1 is OK here. See comment in positiveFloatToDecimal.
+	f(1, 1, 0)
+	f(30, 3, 1)
+	f(12345678900000000, 123456789, 8)
+	f(12345678901234567, 12345678901234568, 0)
+	f(1234567890123456789, 12345678901234567, 2)
+	f(12345678901234567890, 12345678901234567, 3)
+	f(18446744073670737131, 18446744073670737, 3)
+	f(123456789012345678901, 12345678901234568, 4)
+	f(1<<53, 1<<53, 0)
+	f(1<<54, 18014398509481984, 0)
+	f(1<<55, 3602879701896396, 1)
+	f(1<<62, 4611686018427387, 3)
+	f(1<<63, 9223372036854775, 3)
+	f(1<<64, 18446744073709548, 3)
+	f(1<<65, 368934881474191, 5)
+	f(1<<66, 737869762948382, 5)
+	f(1<<67, 1475739525896764, 5)
+
+	f(0.1, 1, -1)
+	f(123456789012345678e-5, 12345678901234568, -4)
+	f(1234567890123456789e-10, 12345678901234568, -8)
+	f(1234567890123456789e-14, 1234567890123, -8)
+	f(1234567890123456789e-17, 12345678901234, -12)
+	f(1234567890123456789e-20, 1234567890123, -14)
+}
+
 func TestAppendDecimalToFloat(t *testing.T) {
 	testAppendDecimalToFloat(t, []int64{}, 0, nil)
 	testAppendDecimalToFloat(t, []int64{0}, 0, []float64{0})
@@ -168,7 +206,7 @@ func TestAppendFloatToDecimal(t *testing.T) {
 	// no-op
 	testAppendFloatToDecimal(t, []float64{}, nil, 0)
 	testAppendFloatToDecimal(t, []float64{0}, []int64{0}, 0)
-	testAppendFloatToDecimal(t, []float64{0, 1, -1, 12345678, -123456789}, []int64{0, 1, -1, 12345678, -123456789}, 0)
+	testAppendFloatToDecimal(t, []float64{0, -0, 1, -1, 12345678, -123456789}, []int64{0, 0, 1, -1, 12345678, -123456789}, 0)
 
 	// upExp
 	testAppendFloatToDecimal(t, []float64{-24, 0, 4.123, 0.3}, []int64{-24000, 0, 4123, 300}, -3)
@@ -248,8 +286,8 @@ func TestFloatToDecimal(t *testing.T) {
 
 	f(math.Inf(1), vInfPos, 0)
 	f(math.Inf(-1), vInfNeg, 0)
-	f(1<<63-1, 922337203685, 7)
-	f(-1<<63, -922337203685, 7)
+	f(1<<63-1, 9223372036854775, 3)
+	f(-1<<63, -9223372036854775, 3)
 
 	// Test precision loss due to conversionPrecision.
 	f(0.1234567890123456, 12345678901234, -14)

lib/decimal/decimal_timing_test.go

@@ -8,17 +8,38 @@ import (
 )
 
 func BenchmarkAppendDecimalToFloat(b *testing.B) {
+	b.Run("VarNums", func(b *testing.B) {
+		benchmarkAppendDecimalToFloat(b, testVA)
+	})
+	b.Run("Zeros", func(b *testing.B) {
+		benchmarkAppendDecimalToFloat(b, testZeros)
+	})
+	b.Run("Ones", func(b *testing.B) {
+		benchmarkAppendDecimalToFloat(b, testOnes)
+	})
+}
+
+func benchmarkAppendDecimalToFloat(b *testing.B, a []int64) {
 	b.ReportAllocs()
-	b.SetBytes(int64(len(testVA)))
+	b.SetBytes(int64(len(a)))
 	b.RunParallel(func(pb *testing.PB) {
 		var fa []float64
 		for pb.Next() {
-			fa = AppendDecimalToFloat(fa[:0], testVA, 0)
+			fa = AppendDecimalToFloat(fa[:0], a, 0)
 			atomic.AddUint64(&Sink, uint64(len(fa)))
 		}
 	})
 }
 
+var testZeros = make([]int64, 8*1024)
+var testOnes = func() []int64 {
+	a := make([]int64, 8*1024)
+	for i := 0; i < len(a); i++ {
+		a[i] = 1
+	}
+	return a
+}()
+
 func BenchmarkAppendFloatToDecimal(b *testing.B) {
 	b.Run("RealFloat", func(b *testing.B) {
 		benchmarkAppendFloatToDecimal(b, testFAReal)
@@ -26,8 +47,23 @@ func BenchmarkAppendFloatToDecimal(b *testing.B) {
 	b.Run("Integers", func(b *testing.B) {
 		benchmarkAppendFloatToDecimal(b, testFAInteger)
 	})
+	b.Run("Zeros", func(b *testing.B) {
+		benchmarkAppendFloatToDecimal(b, testFZeros)
+	})
+	b.Run("Ones", func(b *testing.B) {
+		benchmarkAppendFloatToDecimal(b, testFOnes)
+	})
 }
 
+var testFZeros = make([]float64, 8*1024)
+var testFOnes = func() []float64 {
+	a := make([]float64, 8*1024)
+	for i := 0; i < len(a); i++ {
+		a[i] = 1
+	}
+	return a
+}()
+
 func benchmarkAppendFloatToDecimal(b *testing.B, fa []float64) {
 	b.ReportAllocs()
 	b.SetBytes(int64(len(fa)))

lib/encoding/encoding.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/decimal"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fastnum"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 )
 
@@ -201,6 +202,14 @@ func unmarshalInt64Array(dst []int64, src []byte, mt MarshalType, firstValue int
 		if len(src) > 0 {
 			return nil, fmt.Errorf("unexpected data left in const encoding: %d bytes", len(src))
 		}
+		if firstValue == 0 {
+			dst = fastnum.AppendInt64Zeros(dst, itemsCount)
+			return dst, nil
+		}
+		if firstValue == 1 {
+			dst = fastnum.AppendInt64Ones(dst, itemsCount)
+			return dst, nil
+		}
 		for itemsCount > 0 {
 			dst = append(dst, firstValue)
 			itemsCount--
@@ -267,6 +276,14 @@ func isConst(a []int64) bool {
 	if len(a) == 0 {
 		return false
 	}
+	if fastnum.IsInt64Zeros(a) {
+		// Fast path for array containing only zeros.
+		return true
+	}
+	if fastnum.IsInt64Ones(a) {
+		// Fast path for array containing only ones.
+		return true
+	}
 	v1 := a[0]
 	for _, v := range a {
 		if v != v1 {

lib/encoding/encoding_timing_test.go

@@ -32,7 +32,7 @@ func BenchmarkUnmarshalGaugeArray(b *testing.B) {
 		var dst []int64
 		var err error
 		for pb.Next() {
-			dst, err = unmarshalInt64Array(dst[:0], benchMarshaledGaugeArray, MarshalTypeZSTDNearestDelta, 0, len(benchGaugeArray))
+			dst, err = unmarshalInt64Array(dst[:0], benchMarshaledGaugeArray, MarshalTypeZSTDNearestDelta, benchGaugeArray[0], len(benchGaugeArray))
 			if err != nil {
 				panic(fmt.Errorf("cannot unmarshal gauge array: %s", err))
 			}
@@ -79,7 +79,7 @@ func BenchmarkUnmarshalDeltaConstArray(b *testing.B) {
 		var dst []int64
 		var err error
 		for pb.Next() {
-			dst, err = unmarshalInt64Array(dst[:0], benchMarshaledDeltaConstArray, MarshalTypeDeltaConst, 0, len(benchDeltaConstArray))
+			dst, err = unmarshalInt64Array(dst[:0], benchMarshaledDeltaConstArray, MarshalTypeDeltaConst, benchDeltaConstArray[0], len(benchDeltaConstArray))
 			if err != nil {
 				panic(fmt.Errorf("cannot unmarshal delta const array: %s", err))
 			}
@@ -126,7 +126,7 @@ func BenchmarkUnmarshalConstArray(b *testing.B) {
 		var dst []int64
 		var err error
 		for pb.Next() {
-			dst, err = unmarshalInt64Array(dst[:0], benchMarshaledConstArray, MarshalTypeConst, 0, len(benchConstArray))
+			dst, err = unmarshalInt64Array(dst[:0], benchMarshaledConstArray, MarshalTypeConst, benchConstArray[0], len(benchConstArray))
 			if err != nil {
 				panic(fmt.Errorf("cannot unmarshal const array: %s", err))
 			}
@@ -171,7 +171,7 @@ func BenchmarkUnmarshalZeroConstArray(b *testing.B) {
 		var dst []int64
 		var err error
 		for pb.Next() {
-			dst, err = unmarshalInt64Array(dst[:0], benchMarshaledZeroConstArray, MarshalTypeConst, 0, len(benchZeroConstArray))
+			dst, err = unmarshalInt64Array(dst[:0], benchMarshaledZeroConstArray, MarshalTypeConst, benchZeroConstArray[0], len(benchZeroConstArray))
 			if err != nil {
 				panic(fmt.Errorf("cannot unmarshal zero const array: %s", err))
 			}
@@ -210,7 +210,7 @@ func BenchmarkUnmarshalInt64Array(b *testing.B) {
 		var dst []int64
 		var err error
 		for pb.Next() {
-			dst, err = unmarshalInt64Array(dst[:0], benchMarshaledInt64Array, benchMarshalType, 0, len(benchInt64Array))
+			dst, err = unmarshalInt64Array(dst[:0], benchMarshaledInt64Array, benchMarshalType, benchInt64Array[0], len(benchInt64Array))
 			if err != nil {
 				panic(fmt.Errorf("cannot unmarshal int64 array: %s", err))
 			}

lib/encoding/int.go

@@ -1,6 +1,7 @@
 package encoding
 
 import (
+	"encoding/binary"
 	"fmt"
 	"sync"
 )
@@ -12,8 +13,8 @@ func MarshalUint16(dst []byte, u uint16) []byte {
 
 // UnmarshalUint16 returns unmarshaled uint32 from src.
 func UnmarshalUint16(src []byte) uint16 {
-	_ = src[1]
-	return uint16(src[0])<<8 | uint16(src[1])
+	// This is faster than the manual conversion.
+	return binary.BigEndian.Uint16(src)
 }
 
 // MarshalUint32 appends marshaled v to dst and returns the result.
@@ -23,8 +24,8 @@ func MarshalUint32(dst []byte, u uint32) []byte {
 
 // UnmarshalUint32 returns unmarshaled uint32 from src.
 func UnmarshalUint32(src []byte) uint32 {
-	_ = src[3]
-	return uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3])
+	// This is faster than the manual conversion.
+	return binary.BigEndian.Uint32(src)
 }
 
 // MarshalUint64 appends marshaled v to dst and returns the result.
@@ -34,8 +35,8 @@ func MarshalUint64(dst []byte, u uint64) []byte {
 
 // UnmarshalUint64 returns unmarshaled uint64 from src.
 func UnmarshalUint64(src []byte) uint64 {
-	_ = src[7]
-	return uint64(src[0])<<56 | uint64(src[1])<<48 | uint64(src[2])<<40 | uint64(src[3])<<32 | uint64(src[4])<<24 | uint64(src[5])<<16 | uint64(src[6])<<8 | uint64(src[7])
+	// This is faster than the manual conversion.
+	return binary.BigEndian.Uint64(src)
 }
 
 // MarshalInt16 appends marshaled v to dst and returns the result.
@@ -48,8 +49,8 @@ func MarshalInt16(dst []byte, v int16) []byte {
 
 // UnmarshalInt16 returns unmarshaled int16 from src.
 func UnmarshalInt16(src []byte) int16 {
-	_ = src[1]
-	u := uint16(src[0])<<8 | uint16(src[1])
+	// This is faster than the manual conversion.
+	u := binary.BigEndian.Uint16(src)
 	v := int16(u>>1) ^ (int16(u<<15) >> 15) // zig-zag decoding without branching.
 	return v
 }
@@ -64,8 +65,8 @@ func MarshalInt64(dst []byte, v int64) []byte {
 
 // UnmarshalInt64 returns unmarshaled int64 from src.
 func UnmarshalInt64(src []byte) int64 {
-	_ = src[7]
-	u := uint64(src[0])<<56 | uint64(src[1])<<48 | uint64(src[2])<<40 | uint64(src[3])<<32 | uint64(src[4])<<24 | uint64(src[5])<<16 | uint64(src[6])<<8 | uint64(src[7])
+	// This is faster than the manual conversion.
+	u := binary.BigEndian.Uint64(src)
 	v := int64(u>>1) ^ (int64(u<<63) >> 63) // zig-zag decoding without branching.
 	return v
 }

lib/encoding/int_timing_test.go

@@ -6,6 +6,33 @@ import (
 	"testing"
 )
 
+func BenchmarkMarshalUint64(b *testing.B) {
+	b.ReportAllocs()
+	b.SetBytes(1)
+	b.RunParallel(func(pb *testing.PB) {
+		var dst []byte
+		var sink uint64
+		for pb.Next() {
+			dst = MarshalUint64(dst[:0], sink)
+			sink += uint64(len(dst))
+		}
+		atomic.AddUint64(&Sink, sink)
+	})
+}
+
+func BenchmarkUnmarshalUint64(b *testing.B) {
+	b.ReportAllocs()
+	b.SetBytes(1)
+	b.RunParallel(func(pb *testing.PB) {
+		var sink uint64
+		for pb.Next() {
+			v := UnmarshalUint64(testMarshaledUint64Data)
+			sink += v
+		}
+		atomic.AddUint64(&Sink, sink)
+	})
+}
+
 func BenchmarkMarshalInt64(b *testing.B) {
 	b.ReportAllocs()
 	b.SetBytes(1)
@@ -120,3 +147,4 @@ func benchmarkUnmarshalVarInt64s(b *testing.B, maxValue int64) {
 }
 
 var testMarshaledInt64Data = MarshalInt64(nil, 1234567890)
+var testMarshaledUint64Data = MarshalUint64(nil, 1234567890)

lib/fastnum/fastnum.go

@@ -0,0 +1,144 @@
+package fastnum
+
+import (
+	"bytes"
+	"unsafe"
+)
+
+// AppendInt64Zeros appends items zeros to dst and returns the result.
+//
+// It is faster than the corresponding loop.
+func AppendInt64Zeros(dst []int64, items int) []int64 {
+	return appendInt64Data(dst, items, int64Zeros[:])
+}
+
+// AppendInt64Ones appends items ones to dst and returns the result.
+//
+// It is faster than the correponding loop.
+func AppendInt64Ones(dst []int64, items int) []int64 {
+	return appendInt64Data(dst, items, int64Ones[:])
+}
+
+// AppendFloat64Zeros appends items zeros to dst and returns the result.
+//
+// It is faster than the corresponding loop.
+func AppendFloat64Zeros(dst []float64, items int) []float64 {
+	return appendFloat64Data(dst, items, float64Zeros[:])
+}
+
+// AppendFloat64Ones appends items ones to dst and returns the result.
+//
+// It is faster than the corresponding loop.
+func AppendFloat64Ones(dst []float64, items int) []float64 {
+	return appendFloat64Data(dst, items, float64Ones[:])
+}
+
+// IsInt64Zeros checks whether a contains only zeros.
+func IsInt64Zeros(a []int64) bool {
+	return isInt64Data(a, int64Zeros[:])
+}
+
+// IsInt64Ones checks whether a contains only ones.
+func IsInt64Ones(a []int64) bool {
+	return isInt64Data(a, int64Ones[:])
+}
+
+// IsFloat64Zeros checks whether a contains only zeros.
+func IsFloat64Zeros(a []float64) bool {
+	return isFloat64Data(a, float64Zeros[:])
+}
+
+// IsFloat64Ones checks whether a contains only ones.
+func IsFloat64Ones(a []float64) bool {
+	return isFloat64Data(a, float64Ones[:])
+}
+
+func appendInt64Data(dst []int64, items int, src []int64) []int64 {
+	for items > 0 {
+		n := len(src)
+		if n > items {
+			n = items
+		}
+		dst = append(dst, src[:n]...)
+		items -= n
+	}
+	return dst
+}
+
+func appendFloat64Data(dst []float64, items int, src []float64) []float64 {
+	for items > 0 {
+		n := len(src)
+		if n > items {
+			n = items
+		}
+		dst = append(dst, src[:n]...)
+		items -= n
+	}
+	return dst
+}
+
+func isInt64Data(a, data []int64) bool {
+	if len(a) == 0 {
+		return true
+	}
+	if len(data) != 8*1024 {
+		panic("len(data) must equal to 8*1024")
+	}
+	b := (*[64 * 1024]byte)(unsafe.Pointer(&data[0]))
+	for len(a) > 0 {
+		n := len(data)
+		if n > len(a) {
+			n = len(a)
+		}
+		x := a[:n]
+		a = a[n:]
+		xb := (*[64 * 1024]byte)(unsafe.Pointer(&x[0]))
+		xbLen := len(x) * 8
+		if !bytes.Equal(xb[:xbLen], b[:xbLen]) {
+			return false
+		}
+	}
+	return true
+}
+
+func isFloat64Data(a, data []float64) bool {
+	if len(a) == 0 {
+		return true
+	}
+	if len(data) != 8*1024 {
+		panic("len(data) must equal to 8*1024")
+	}
+	b := (*[64 * 1024]byte)(unsafe.Pointer(&data[0]))
+	for len(a) > 0 {
+		n := len(data)
+		if n > len(a) {
+			n = len(a)
+		}
+		x := a[:n]
+		a = a[n:]
+		xb := (*[64 * 1024]byte)(unsafe.Pointer(&x[0]))
+		xbLen := len(x) * 8
+		if !bytes.Equal(xb[:xbLen], b[:xbLen]) {
+			return false
+		}
+	}
+	return true
+}
+
+var (
+	int64Zeros [8 * 1024]int64
+	int64Ones  = func() (a [8 * 1024]int64) {
+		for i := 0; i < len(a); i++ {
+			a[i] = 1
+		}
+		return a
+	}()
+
+	float64Zeros [8 * 1024]float64
+	float64Ones  = func() (a [8 * 1024]float64) {
+		for i := 0; i < len(a); i++ {
+			a[i] = 1
+		}
+		return a
+	}()
+)

lib/fastnum/fastnum_test.go

@@ -0,0 +1,192 @@
+package fastnum
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestIsInt64Zeros(t *testing.T) {
+	for _, n := range []int{0, 1, 10, 100, 1000, 1e4, 1e5, 8*1024 + 1} {
+		t.Run(fmt.Sprintf("%d_items", n), func(t *testing.T) {
+			a := make([]int64, n)
+			if !IsInt64Zeros(a) {
+				t.Fatalf("IsInt64Zeros must return true")
+			}
+			if len(a) > 0 {
+				a[len(a)-1] = 1
+				if IsInt64Zeros(a) {
+					t.Fatalf("IsInt64Zeros must return false")
+				}
+			}
+		})
+	}
+}
+
+func TestIsInt64Ones(t *testing.T) {
+	for _, n := range []int{0, 1, 10, 100, 1000, 1e4, 1e5, 8*1024 + 1} {
+		t.Run(fmt.Sprintf("%d_items", n), func(t *testing.T) {
+			a := make([]int64, n)
+			for i := 0; i < n; i++ {
+				a[i] = 1
+			}
+			if !IsInt64Ones(a) {
+				t.Fatalf("IsInt64Ones must return true")
+			}
+			if len(a) > 0 {
+				a[len(a)-1] = 0
+				if IsInt64Ones(a) {
+					t.Fatalf("IsInt64Ones must return false")
+				}
+			}
+		})
+	}
+}
+
+func TestIsFloat64Zeros(t *testing.T) {
+	for _, n := range []int{0, 1, 10, 100, 1000, 1e4, 1e5, 8*1024 + 1} {
+		t.Run(fmt.Sprintf("%d_items", n), func(t *testing.T) {
+			a := make([]float64, n)
+			if !IsFloat64Zeros(a) {
+				t.Fatalf("IsInt64Zeros must return true")
+			}
+			if len(a) > 0 {
+				a[len(a)-1] = 1
+				if IsFloat64Zeros(a) {
+					t.Fatalf("IsInt64Zeros must return false")
+				}
+			}
+		})
+	}
+}
+
+func TestIsFloat64Ones(t *testing.T) {
+	for _, n := range []int{0, 1, 10, 100, 1000, 1e4, 1e5, 8*1024 + 1} {
+		t.Run(fmt.Sprintf("%d_items", n), func(t *testing.T) {
+			a := make([]float64, n)
+			for i := 0; i < n; i++ {
+				a[i] = 1
+			}
+			if !IsFloat64Ones(a) {
+				t.Fatalf("IsInt64Ones must return true")
+			}
+			if len(a) > 0 {
+				a[len(a)-1] = 0
+				if IsFloat64Ones(a) {
+					t.Fatalf("IsInt64Ones must return false")
+				}
+			}
+		})
+	}
+}
+
+func TestAppendInt64Zeros(t *testing.T) {
+	for _, n := range []int{0, 1, 10, 100, 1000, 1e4, 1e5, 8*1024 + 1} {
+		t.Run(fmt.Sprintf("%d_items", n), func(t *testing.T) {
+			a := AppendInt64Zeros(nil, n)
+			if len(a) != n {
+				t.Fatalf("unexpected len(a); got %d; want %d", len(a), n)
+			}
+			if !IsInt64Zeros(a) {
+				t.Fatalf("IsInt64Zeros must return true")
+			}
+
+			prefix := []int64{1, 2, 3}
+			a = AppendInt64Zeros(prefix, n)
+			if len(a) != len(prefix)+n {
+				t.Fatalf("unexpected len(a) with prefix; got %d; want %d", len(a), len(prefix)+n)
+			}
+			for i := 0; i < len(prefix); i++ {
+				if a[i] != prefix[i] {
+					t.Fatalf("unexpected prefix[%d]; got %d; want %d", i, a[i], prefix[i])
+				}
+			}
+			if !IsInt64Zeros(a[len(prefix):]) {
+				t.Fatalf("IsInt64Zeros for prefixed a must return true")
+			}
+		})
+	}
+}
+
+func TestAppendInt64Ones(t *testing.T) {
+	for _, n := range []int{0, 1, 10, 100, 1000, 1e4, 1e5, 8*1024 + 1} {
+		t.Run(fmt.Sprintf("%d_items", n), func(t *testing.T) {
+			a := AppendInt64Ones(nil, n)
+			if len(a) != n {
+				t.Fatalf("unexpected len(a); got %d; want %d", len(a), n)
+			}
+			if !IsInt64Ones(a) {
+				t.Fatalf("IsInt64Ones must return true")
+			}
+
+			prefix := []int64{1, 2, 3}
+			a = AppendInt64Ones(prefix, n)
+			if len(a) != len(prefix)+n {
+				t.Fatalf("unexpected len(a) with prefix; got %d; want %d", len(a), len(prefix)+n)
+			}
+			for i := 0; i < len(prefix); i++ {
+				if a[i] != prefix[i] {
+					t.Fatalf("unexpected prefix[%d]; got %d; want %d", i, a[i], prefix[i])
+				}
+			}
+			if !IsInt64Ones(a[len(prefix):]) {
+				t.Fatalf("IsInt64Ones for prefixed a must return true")
+			}
+		})
+	}
+}
+
+func TestAppendFloat64Zeros(t *testing.T) {
+	for _, n := range []int{0, 1, 10, 100, 1000, 1e4, 1e5, 8*1024 + 1} {
+		t.Run(fmt.Sprintf("%d_items", n), func(t *testing.T) {
+			a := AppendFloat64Zeros(nil, n)
+			if len(a) != n {
+				t.Fatalf("unexpected len(a); got %d; want %d", len(a), n)
+			}
+			if !IsFloat64Zeros(a) {
+				t.Fatalf("IsFloat64Zeros must return true")
+			}
+
+			prefix := []float64{1, 2, 3}
+			a = AppendFloat64Zeros(prefix, n)
+			if len(a) != len(prefix)+n {
+				t.Fatalf("unexpected len(a) with prefix; got %d; want %d", len(a), len(prefix)+n)
+			}
+			for i := 0; i < len(prefix); i++ {
+				if a[i] != prefix[i] {
+					t.Fatalf("unexpected prefix[%d]; got %f; want %f", i, a[i], prefix[i])
+				}
+			}
+			if !IsFloat64Zeros(a[len(prefix):]) {
+				t.Fatalf("IsFloat64Zeros for prefixed a must return true")
+			}
+		})
+	}
+}
+
+func TestAppendFloat64Ones(t *testing.T) {
+	for _, n := range []int{0, 1, 10, 100, 1000, 1e4, 1e5, 8*1024 + 1} {
+		t.Run(fmt.Sprintf("%d_items", n), func(t *testing.T) {
+			a := AppendFloat64Ones(nil, n)
+			if len(a) != n {
+				t.Fatalf("unexpected len(a); got %d; want %d", len(a), n)
+			}
+			if !IsFloat64Ones(a) {
+				t.Fatalf("IsFloat64Ones must return true")
+			}
+
+			prefix := []float64{1, 2, 3}
+			a = AppendFloat64Ones(prefix, n)
+			if len(a) != len(prefix)+n {
+				t.Fatalf("unexpected len(a) with prefix; got %d; want %d", len(a), len(prefix)+n)
+			}
+			for i := 0; i < len(prefix); i++ {
+				if a[i] != prefix[i] {
+					t.Fatalf("unexpected prefix[%d]; got %f; want %f", i, a[i], prefix[i])
+				}
+			}
+			if !IsFloat64Ones(a[len(prefix):]) {
+				t.Fatalf("IsFloat64Ones for prefixed a must return true")
+			}
+		})
+	}
+}

lib/fs/fs.go

@@ -92,7 +92,7 @@ var tmpFileNum uint64
 
 // WriteFileAtomically atomically writes data to the given file path.
 //
-// WriteFile returns only after the file is fully written and synced
+// WriteFileAtomically returns only after the file is fully written and synced
 // to the underlying storage.
 func WriteFileAtomically(path string, data []byte) error {
 	// Check for the existing file. It is expected that

lib/memory/memory_linux.go

@@ -9,12 +9,17 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 )
 
+const maxInt = int(^uint(0) >> 1)
+
 func sysTotalMemory() int {
 	var si syscall.Sysinfo_t
 	if err := syscall.Sysinfo(&si); err != nil {
 		logger.Panicf("FATAL: error in syscall.Sysinfo: %s", err)
 	}
-	totalMem := int(si.Totalram) * int(si.Unit)
+	totalMem := maxInt
+	if uint64(maxInt)/uint64(si.Totalram) > uint64(si.Unit) {
+		totalMem = int(uint64(si.Totalram) * uint64(si.Unit))
+	}
 
 	// Try determining the amount of memory inside docker container.
 	// See https://stackoverflow.com/questions/42187085/check-mem-limit-within-a-docker-container .

lib/mergeset/encoding.go

@@ -2,6 +2,7 @@ package mergeset
 
 import (
 	"fmt"
+	"os"
 	"sort"
 	"strings"
 	"sync"
@@ -11,10 +12,20 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 )
 
+type byteSliceSorter [][]byte
+
+func (s byteSliceSorter) Len() int { return len(s) }
+func (s byteSliceSorter) Less(i, j int) bool {
+	return string(s[i]) < string(s[j])
+}
+func (s byteSliceSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
 type inmemoryBlock struct {
 	commonPrefix []byte
 	data         []byte
-	items        [][]byte
+	items        byteSliceSorter
 }
 
 func (ib *inmemoryBlock) Reset() {
@@ -77,12 +88,9 @@ func (ib *inmemoryBlock) Add(x []byte) bool {
 // It must fit CPU cache size, i.e. 64KB for the current CPUs.
 const maxInmemoryBlockSize = 64 * 1024
 
-func (ib *inmemoryBlock) itemsLess(i, j int) bool {
-	return string(ib.items[i]) < string(ib.items[j])
-}
-
 func (ib *inmemoryBlock) sort() {
-	sort.Slice(ib.items, ib.itemsLess)
+	// Use sort.Sort instead of sort.Slice in order to eliminate memory allocation.
+	sort.Sort(&ib.items)
 	bb := bbPool.Get()
 	b := bytesutil.Resize(bb.B, len(ib.data))
 	b = b[:0]
@@ -120,7 +128,8 @@ func checkMarshalType(mt marshalType) error {
 }
 
 func (ib *inmemoryBlock) isSorted() bool {
-	return sort.SliceIsSorted(ib.items, ib.itemsLess)
+	// Use sort.IsSorted instead of sort.SliceIsSorted in order to eliminate memory allocation.
+	return sort.IsSorted(&ib.items)
 }
 
 // MarshalUnsortedData marshals unsorted items from ib to sb.
@@ -138,6 +147,10 @@ func (ib *inmemoryBlock) MarshalUnsortedData(sb *storageBlock, firstItemDst, com
 	return ib.marshalData(sb, firstItemDst, commonPrefixDst, compressLevel)
 }
 
+var isInTest = func() bool {
+	return strings.HasSuffix(os.Args[0], ".test")
+}()
+
 // MarshalUnsortedData marshals sorted items from ib to sb.
 //
 // It also:
@@ -146,17 +159,22 @@ func (ib *inmemoryBlock) MarshalUnsortedData(sb *storageBlock, firstItemDst, com
 // - returns the number of items encoded including the first item.
 // - returns the marshal type used for the encoding.
 func (ib *inmemoryBlock) MarshalSortedData(sb *storageBlock, firstItemDst, commonPrefixDst []byte, compressLevel int) ([]byte, []byte, uint32, marshalType) {
-	// if !ib.isSorted() {
-	//	logger.Panicf("BUG: %d items must be sorted; items:\n%s", len(ib.items), ib.debugItemsString())
-	// }
+	if isInTest && !ib.isSorted() {
+		logger.Panicf("BUG: %d items must be sorted; items:\n%s", len(ib.items), ib.debugItemsString())
+	}
 	ib.updateCommonPrefix()
 	return ib.marshalData(sb, firstItemDst, commonPrefixDst, compressLevel)
 }
 
 func (ib *inmemoryBlock) debugItemsString() string {
 	var sb strings.Builder
+	var prevItem []byte
 	for i, item := range ib.items {
+		if string(item) < string(prevItem) {
+			fmt.Fprintf(&sb, "!!! the next item is smaller than the previous item !!!\n")
+		}
 		fmt.Fprintf(&sb, "%05d %X\n", i, item)
+		prevItem = item
 	}
 	return sb.String()
 }
@@ -175,7 +193,7 @@ func (ib *inmemoryBlock) marshalData(sb *storageBlock, firstItemDst, commonPrefi
 	firstItemDst = append(firstItemDst, ib.items[0]...)
 	commonPrefixDst = append(commonPrefixDst, ib.commonPrefix...)
 
-	if len(ib.data)-len(ib.commonPrefix)*len(ib.items) < 64 || len(ib.items) < 10 {
+	if len(ib.data)-len(ib.commonPrefix)*len(ib.items) < 64 || len(ib.items) < 2 {
 		// Use plain encoding form small block, since it is cheaper.
 		ib.marshalDataPlain(sb)
 		return firstItemDst, commonPrefixDst, uint32(len(ib.items)), marshalTypePlain

lib/mergeset/merge.go

@@ -5,18 +5,31 @@ import (
 	"fmt"
 	"sync"
 	"sync/atomic"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 )
 
+// PrepareBlockCallback can transform the passed items allocated at the given data.
+//
+// The callback is called during merge before flushing full block of the given items
+// to persistent storage.
+//
+// The callback must return sorted items. The first and the last item must be unchanged.
+// The callback can re-use data and items for storing the result.
+type PrepareBlockCallback func(data []byte, items [][]byte) ([]byte, [][]byte)
+
 // mergeBlockStreams merges bsrs and writes result to bsw.
 //
 // It also fills ph.
 //
+// prepareBlock is optional.
+//
 // The function immediately returns when stopCh is closed.
 //
 // It also atomically adds the number of items merged to itemsMerged.
-func mergeBlockStreams(ph *partHeader, bsw *blockStreamWriter, bsrs []*blockStreamReader, stopCh <-chan struct{}, itemsMerged *uint64) error {
+func mergeBlockStreams(ph *partHeader, bsw *blockStreamWriter, bsrs []*blockStreamReader, prepareBlock PrepareBlockCallback, stopCh <-chan struct{}, itemsMerged *uint64) error {
 	bsm := bsmPool.Get().(*blockStreamMerger)
-	if err := bsm.Init(bsrs); err != nil {
+	if err := bsm.Init(bsrs, prepareBlock); err != nil {
 		return fmt.Errorf("cannot initialize blockStreamMerger: %s", err)
 	}
 	err := bsm.Merge(bsw, ph, stopCh, itemsMerged)
@@ -39,15 +52,24 @@ var bsmPool = &sync.Pool{
 }
 
 type blockStreamMerger struct {
+	prepareBlock PrepareBlockCallback
+
 	bsrHeap bsrHeap
 
 	// ib is a scratch block with pending items.
 	ib inmemoryBlock
 
 	phFirstItemCaught bool
+
+	// This are auxiliary buffers used in flushIB
+	// for consistency checks after prepareBlock call.
+	firstItem []byte
+	lastItem  []byte
 }
 
 func (bsm *blockStreamMerger) reset() {
+	bsm.prepareBlock = nil
+
 	for i := range bsm.bsrHeap {
 		bsm.bsrHeap[i] = nil
 	}
@@ -57,8 +79,9 @@ func (bsm *blockStreamMerger) reset() {
 	bsm.phFirstItemCaught = false
 }
 
-func (bsm *blockStreamMerger) Init(bsrs []*blockStreamReader) error {
+func (bsm *blockStreamMerger) Init(bsrs []*blockStreamReader, prepareBlock PrepareBlockCallback) error {
 	bsm.reset()
+	bsm.prepareBlock = prepareBlock
 	for _, bsr := range bsrs {
 		if bsr.Next() {
 			bsm.bsrHeap = append(bsm.bsrHeap, bsr)
@@ -95,25 +118,23 @@ again:
 
 	bsr := heap.Pop(&bsm.bsrHeap).(*blockStreamReader)
 
-	if !bsm.phFirstItemCaught {
-		ph.firstItem = append(ph.firstItem[:0], bsr.Block.items[0]...)
-		bsm.phFirstItemCaught = true
-	}
-
 	var nextItem []byte
 	hasNextItem := false
 	if len(bsm.bsrHeap) > 0 {
 		nextItem = bsm.bsrHeap[0].bh.firstItem
 		hasNextItem = true
 	}
-	for bsr.blockItemIdx < len(bsr.Block.items) && (!hasNextItem || string(bsr.Block.items[bsr.blockItemIdx]) <= string(nextItem)) {
-		if bsm.ib.Add(bsr.Block.items[bsr.blockItemIdx]) {
-			bsr.blockItemIdx++
+	for bsr.blockItemIdx < len(bsr.Block.items) {
+		item := bsr.Block.items[bsr.blockItemIdx]
+		if hasNextItem && string(item) > string(nextItem) {
+			break
+		}
+		if !bsm.ib.Add(item) {
+			// The bsm.ib is full. Flush it to bsw and continue.
+			bsm.flushIB(bsw, ph, itemsMerged)
 			continue
 		}
-
-		// The bsm.ib is full. Flush it to bsw and continue.
-		bsm.flushIB(bsw, ph, itemsMerged)
+		bsr.blockItemIdx++
 	}
 	if bsr.blockItemIdx == len(bsr.Block.items) {
 		// bsr.Block is fully read. Proceed to the next block.
@@ -139,9 +160,35 @@ func (bsm *blockStreamMerger) flushIB(bsw *blockStreamWriter, ph *partHeader, it
 		// Nothing to flush.
 		return
 	}
-	itemsCount := uint64(len(bsm.ib.items))
-	ph.itemsCount += itemsCount
-	atomic.AddUint64(itemsMerged, itemsCount)
+	atomic.AddUint64(itemsMerged, uint64(len(bsm.ib.items)))
+	if bsm.prepareBlock != nil {
+		bsm.firstItem = append(bsm.firstItem[:0], bsm.ib.items[0]...)
+		bsm.lastItem = append(bsm.lastItem[:0], bsm.ib.items[len(bsm.ib.items)-1]...)
+		bsm.ib.data, bsm.ib.items = bsm.prepareBlock(bsm.ib.data, bsm.ib.items)
+		if len(bsm.ib.items) == 0 {
+			// Nothing to flush
+			return
+		}
+		// Consistency checks after prepareBlock call.
+		firstItem := bsm.ib.items[0]
+		if string(firstItem) != string(bsm.firstItem) {
+			logger.Panicf("BUG: prepareBlock must return first item equal to the original first item;\ngot\n%X\nwant\n%X", firstItem, bsm.firstItem)
+		}
+		lastItem := bsm.ib.items[len(bsm.ib.items)-1]
+		if string(lastItem) != string(bsm.lastItem) {
+			logger.Panicf("BUG: prepareBlock must return last item equal to the original last item;\ngot\n%X\nwant\n%X", lastItem, bsm.lastItem)
+		}
+		// Verify whether the bsm.ib.items are sorted only in tests, since this
+		// can be expensive check in prod for items with long common prefix.
+		if isInTest && !bsm.ib.isSorted() {
+			logger.Panicf("BUG: prepareBlock must return sorted items;\ngot\n%s", bsm.ib.debugItemsString())
+		}
+	}
+	ph.itemsCount += uint64(len(bsm.ib.items))
+	if !bsm.phFirstItemCaught {
+		ph.firstItem = append(ph.firstItem[:0], bsm.ib.items[0]...)
+		bsm.phFirstItemCaught = true
+	}
 	ph.lastItem = append(ph.lastItem[:0], bsm.ib.items[len(bsm.ib.items)-1]...)
 	bsw.WriteBlock(&bsm.ib)
 	bsm.ib.Reset()

lib/mergeset/merge_test.go

@@ -30,14 +30,14 @@ func TestMultilevelMerge(t *testing.T) {
 	var dstIP1 inmemoryPart
 	var bsw1 blockStreamWriter
 	bsw1.InitFromInmemoryPart(&dstIP1, 0)
-	if err := mergeBlockStreams(&dstIP1.ph, &bsw1, bsrs[:5], nil, &itemsMerged); err != nil {
+	if err := mergeBlockStreams(&dstIP1.ph, &bsw1, bsrs[:5], nil, nil, &itemsMerged); err != nil {
 		t.Fatalf("cannot merge first level part 1: %s", err)
 	}
 
 	var dstIP2 inmemoryPart
 	var bsw2 blockStreamWriter
 	bsw2.InitFromInmemoryPart(&dstIP2, 0)
-	if err := mergeBlockStreams(&dstIP2.ph, &bsw2, bsrs[5:], nil, &itemsMerged); err != nil {
+	if err := mergeBlockStreams(&dstIP2.ph, &bsw2, bsrs[5:], nil, nil, &itemsMerged); err != nil {
 		t.Fatalf("cannot merge first level part 2: %s", err)
 	}
 
@@ -54,7 +54,7 @@ func TestMultilevelMerge(t *testing.T) {
 		newTestBlockStreamReader(&dstIP2),
 	}
 	bsw.InitFromInmemoryPart(&dstIP, 0)
-	if err := mergeBlockStreams(&dstIP.ph, &bsw, bsrsTop, nil, &itemsMerged); err != nil {
+	if err := mergeBlockStreams(&dstIP.ph, &bsw, bsrsTop, nil, nil, &itemsMerged); err != nil {
 		t.Fatalf("cannot merge second level: %s", err)
 	}
 	if itemsMerged != uint64(len(items)) {
@@ -76,7 +76,7 @@ func TestMergeForciblyStop(t *testing.T) {
 	ch := make(chan struct{})
 	var itemsMerged uint64
 	close(ch)
-	if err := mergeBlockStreams(&dstIP.ph, &bsw, bsrs, ch, &itemsMerged); err != errForciblyStopped {
+	if err := mergeBlockStreams(&dstIP.ph, &bsw, bsrs, nil, ch, &itemsMerged); err != errForciblyStopped {
 		t.Fatalf("unexpected error during merge: got %v; want %v", err, errForciblyStopped)
 	}
 	if itemsMerged != 0 {
@@ -120,7 +120,7 @@ func testMergeBlockStreamsSerial(blocksToMerge, maxItemsPerBlock int) error {
 	var dstIP inmemoryPart
 	var bsw blockStreamWriter
 	bsw.InitFromInmemoryPart(&dstIP, 0)
-	if err := mergeBlockStreams(&dstIP.ph, &bsw, bsrs, nil, &itemsMerged); err != nil {
+	if err := mergeBlockStreams(&dstIP.ph, &bsw, bsrs, nil, nil, &itemsMerged); err != nil {
 		return fmt.Errorf("cannot merge block streams: %s", err)
 	}
 	if itemsMerged != uint64(len(items)) {

lib/mergeset/part.go

@@ -5,6 +5,7 @@ import (
 	"path/filepath"
 	"sync"
 	"sync/atomic"
+	"unsafe"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/filestream"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fs"
@@ -13,7 +14,7 @@ import (
 
 func getMaxCachedIndexBlocksPerPart() int {
 	maxCachedIndexBlocksPerPartOnce.Do(func() {
-		n := memory.Allowed() / 1024 / 1024 / 2
+		n := memory.Allowed() / 1024 / 1024 / 4
 		if n == 0 {
 			n = 10
 		}
@@ -29,7 +30,7 @@ var (
 
 func getMaxCachedInmemoryBlocksPerPart() int {
 	maxCachedInmemoryBlocksPerPartOnce.Do(func() {
-		n := memory.Allowed() / 1024 / 1024 / 2
+		n := memory.Allowed() / 1024 / 1024 / 4
 		if n == 0 {
 			n = 10
 		}
@@ -43,7 +44,7 @@ var (
 	maxCachedInmemoryBlocksPerPartOnce sync.Once
 )
 
-type part struct {
+type partInternals struct {
 	ph partHeader
 
 	path string
@@ -55,7 +56,14 @@ type part struct {
 	indexFile fs.ReadAtCloser
 	itemsFile fs.ReadAtCloser
 	lensFile  fs.ReadAtCloser
+}
 
+type part struct {
+	partInternals
+
+	// Align atomic counters inside caches by 8 bytes on 32-bit architectures.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212 .
+	_         [(8 - (unsafe.Sizeof(partInternals{}) % 8)) % 8]byte
 	idxbCache indexBlockCache
 	ibCache   inmemoryBlockCache
 }
@@ -114,15 +122,15 @@ func newPart(ph *partHeader, path string, size uint64, metaindexReader filestrea
 	}
 	metaindexReader.MustClose()
 
-	p := &part{
-		path: path,
-		size: size,
-		mrs:  mrs,
+	var p part
+	p.path = path
+	p.size = size
+	p.mrs = mrs
+
+	p.indexFile = indexFile
+	p.itemsFile = itemsFile
+	p.lensFile = lensFile
 
-		indexFile: indexFile,
-		itemsFile: itemsFile,
-		lensFile:  lensFile,
-	}
 	p.ph.CopyFrom(ph)
 	p.idxbCache.Init()
 	p.ibCache.Init()
@@ -133,7 +141,7 @@ func newPart(ph *partHeader, path string, size uint64, metaindexReader filestrea
 		p.MustClose()
 		return nil, err
 	}
-	return p, nil
+	return &p, nil
 }
 
 func (p *part) MustClose() {
@@ -165,12 +173,15 @@ func putIndexBlock(idxb *indexBlock) {
 var indexBlockPool sync.Pool
 
 type indexBlockCache struct {
+	// Atomically updated counters must go first in the struct, so they are properly
+	// aligned to 8 bytes on 32-bit architectures.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212
+	requests uint64
+	misses   uint64
+
 	m         map[uint64]*indexBlock
 	missesMap map[uint64]uint64
 	mu        sync.RWMutex
-
-	requests uint64
-	misses   uint64
 }
 
 func (idxbc *indexBlockCache) Init() {
@@ -274,12 +285,15 @@ func (idxbc *indexBlockCache) Misses() uint64 {
 }
 
 type inmemoryBlockCache struct {
+	// Atomically updated counters must go first in the struct, so they are properly
+	// aligned to 8 bytes on 32-bit architectures.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212
+	requests uint64
+	misses   uint64
+
 	m         map[inmemoryBlockCacheKey]*inmemoryBlock
 	missesMap map[inmemoryBlockCacheKey]uint64
 	mu        sync.RWMutex
-
-	requests uint64
-	misses   uint64
 }
 
 type inmemoryBlockCacheKey struct {

lib/mergeset/part_search.go

@@ -31,6 +31,8 @@ type partSearch struct {
 	// Pointer to inmemory block, which may be reused.
 	inmemoryBlockReuse *inmemoryBlock
 
+	shouldCacheBlock func(item []byte) bool
+
 	idxbCache *indexBlockCache
 	ibCache   *inmemoryBlockCache
 
@@ -59,6 +61,7 @@ func (ps *partSearch) reset() {
 		putInmemoryBlock(ps.inmemoryBlockReuse)
 		ps.inmemoryBlockReuse = nil
 	}
+	ps.shouldCacheBlock = nil
 	ps.idxbCache = nil
 	ps.ibCache = nil
 	ps.err = nil
@@ -75,7 +78,7 @@ func (ps *partSearch) reset() {
 // Init initializes ps for search in the p.
 //
 // Use Seek for search in p.
-func (ps *partSearch) Init(p *part) {
+func (ps *partSearch) Init(p *part, shouldCacheBlock func(item []byte) bool) {
 	ps.reset()
 
 	ps.p = p
@@ -324,6 +327,16 @@ func (ps *partSearch) readIndexBlock(mr *metaindexRow) (*indexBlock, error) {
 }
 
 func (ps *partSearch) getInmemoryBlock(bh *blockHeader) (*inmemoryBlock, bool, error) {
+	if ps.shouldCacheBlock != nil {
+		if !ps.shouldCacheBlock(bh.firstItem) {
+			ib, err := ps.readInmemoryBlock(bh)
+			if err != nil {
+				return nil, false, err
+			}
+			return ib, true, nil
+		}
+	}
+
 	var ibKey inmemoryBlockCacheKey
 	ibKey.Init(bh)
 	ib := ps.ibCache.Get(ibKey)
@@ -371,7 +384,7 @@ func binarySearchKey(items [][]byte, key []byte) int {
 	i, j := uint(0), n
 	for i < j {
 		h := uint(i+j) >> 1
-		if string(key) > string(items[h]) {
+		if h >= 0 && h < uint(len(items)) && string(key) > string(items[h]) {
 			i = h + 1
 		} else {
 			j = h

lib/mergeset/part_search_test.go

@@ -51,7 +51,7 @@ func testPartSearchConcurrent(p *part, items []string) error {
 func testPartSearchSerial(p *part, items []string) error {
 	var ps partSearch
 
-	ps.Init(p)
+	ps.Init(p, nil)
 	var k []byte
 
 	// Search for the item smaller than the items[0]
@@ -150,7 +150,7 @@ func newTestPart(blocksCount, maxItemsPerBlock int) (*part, []string, error) {
 	var ip inmemoryPart
 	var bsw blockStreamWriter
 	bsw.InitFromInmemoryPart(&ip, 0)
-	if err := mergeBlockStreams(&ip.ph, &bsw, bsrs, nil, &itemsMerged); err != nil {
+	if err := mergeBlockStreams(&ip.ph, &bsw, bsrs, nil, nil, &itemsMerged); err != nil {
 		return nil, nil, fmt.Errorf("cannot merge blocks: %s", err)
 	}
 	if itemsMerged != uint64(len(items)) {

lib/mergeset/table.go

@@ -70,10 +70,23 @@ const rawItemsFlushInterval = time.Second
 
 // Table represents mergeset table.
 type Table struct {
+	// Atomically updated counters must go first in the struct, so they are properly
+	// aligned to 8 bytes on 32-bit architectures.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212
+
+	activeMerges   uint64
+	mergesCount    uint64
+	itemsMerged    uint64
+	assistedMerges uint64
+
+	mergeIdx uint64
+
 	path string
 
 	flushCallback func()
 
+	prepareBlock PrepareBlockCallback
+
 	partsLock sync.Mutex
 	parts     []*partWrapper
 
@@ -81,8 +94,6 @@ type Table struct {
 	rawItemsLock          sync.Mutex
 	rawItemsLastFlushTime time.Time
 
-	mergeIdx uint64
-
 	snapshotLock sync.RWMutex
 
 	flockF *os.File
@@ -94,13 +105,10 @@ type Table struct {
 
 	rawItemsFlusherWG sync.WaitGroup
 
+	convertersWG sync.WaitGroup
+
 	// Use syncwg instead of sync, since Add/Wait may be called from concurrent goroutines.
 	rawItemsPendingFlushesWG syncwg.WaitGroup
-
-	activeMerges   uint64
-	mergesCount    uint64
-	itemsMerged    uint64
-	assistedMerges uint64
 }
 
 type partWrapper struct {
@@ -139,8 +147,11 @@ func (pw *partWrapper) decRef() {
 // Optional flushCallback is called every time new data batch is flushed
 // to the underlying storage and becomes visible to search.
 //
+// Optional prepareBlock is called during merge before flushing the prepared block
+// to persistent storage.
+//
 // The table is created if it doesn't exist yet.
-func OpenTable(path string, flushCallback func()) (*Table, error) {
+func OpenTable(path string, flushCallback func(), prepareBlock PrepareBlockCallback) (*Table, error) {
 	path = filepath.Clean(path)
 	logger.Infof("opening table %q...", path)
 	startTime := time.Now()
@@ -165,6 +176,7 @@ func OpenTable(path string, flushCallback func()) (*Table, error) {
 	tb := &Table{
 		path:          path,
 		flushCallback: flushCallback,
+		prepareBlock:  prepareBlock,
 		parts:         pws,
 		mergeIdx:      uint64(time.Now().UnixNano()),
 		flockF:        flockF,
@@ -178,6 +190,12 @@ func OpenTable(path string, flushCallback func()) (*Table, error) {
 	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)
 
+	tb.convertersWG.Add(1)
+	go func() {
+		tb.convertToV1280()
+		tb.convertersWG.Done()
+	}()
+
 	return tb, nil
 }
 
@@ -190,6 +208,11 @@ func (tb *Table) MustClose() {
 	tb.rawItemsFlusherWG.Wait()
 	logger.Infof("raw items flusher stopped in %s on %q", time.Since(startTime), tb.path)
 
+	logger.Infof("waiting for converters to stop on %q...", tb.path)
+	startTime = time.Now()
+	tb.convertersWG.Wait()
+	logger.Infof("converters stopped in %s on %q", time.Since(startTime), tb.path)
+
 	logger.Infof("waiting for part mergers to stop on %q...", tb.path)
 	startTime = time.Now()
 	tb.partMergersWG.Wait()
@@ -216,7 +239,7 @@ func (tb *Table) MustClose() {
 	}
 	tb.partsLock.Unlock()
 
-	if err := tb.mergePartsOptimal(pws); err != nil {
+	if err := tb.mergePartsOptimal(pws, nil); err != nil {
 		logger.Panicf("FATAL: cannot flush inmemory parts to files in %q: %s", tb.path, err)
 	}
 	logger.Infof("%d inmemory parts have been flushed to files in %s on %q", len(pws), time.Since(startTime), tb.path)
@@ -393,15 +416,67 @@ func (tb *Table) rawItemsFlusher() {
 	}
 }
 
-func (tb *Table) mergePartsOptimal(pws []*partWrapper) error {
+const convertToV1280FileName = "converted-to-v1.28.0"
+
+func (tb *Table) convertToV1280() {
+	// Convert tag->metricID rows into tag->metricIDs rows when upgrading to v1.28.0+.
+	flagFilePath := tb.path + "/" + convertToV1280FileName
+	if fs.IsPathExist(flagFilePath) {
+		// The conversion has been already performed.
+		return
+	}
+
+	getAllPartsForMerge := func() []*partWrapper {
+		var pws []*partWrapper
+		tb.partsLock.Lock()
+		for _, pw := range tb.parts {
+			if pw.isInMerge {
+				continue
+			}
+			pw.isInMerge = true
+			pws = append(pws, pw)
+		}
+		tb.partsLock.Unlock()
+		return pws
+	}
+	pws := getAllPartsForMerge()
+	if len(pws) > 0 {
+		logger.Infof("started round 1 of background conversion of %q to v1.28.0 format; merge %d parts", tb.path, len(pws))
+		startTime := time.Now()
+		if err := tb.mergePartsOptimal(pws, tb.stopCh); err != nil {
+			logger.Errorf("failed round 1 of background conversion of %q to v1.28.0 format: %s", tb.path, err)
+			return
+		}
+		logger.Infof("finished round 1 of background conversion of %q to v1.28.0 format in %s", tb.path, time.Since(startTime))
+
+		// The second round is needed in order to merge small blocks
+		// with tag->metricIDs rows left after the first round.
+		pws = getAllPartsForMerge()
+		logger.Infof("started round 2 of background conversion of %q to v1.28.0 format; merge %d parts", tb.path, len(pws))
+		startTime = time.Now()
+		if len(pws) > 0 {
+			if err := tb.mergePartsOptimal(pws, tb.stopCh); err != nil {
+				logger.Errorf("failed round 2 of background conversion of %q to v1.28.0 format: %s", tb.path, err)
+				return
+			}
+		}
+		logger.Infof("finished round 2 of background conversion of %q to v1.28.0 format in %s", tb.path, time.Since(startTime))
+	}
+
+	if err := fs.WriteFileAtomically(flagFilePath, []byte("ok")); err != nil {
+		logger.Panicf("FATAL: cannot create %q: %s", flagFilePath, err)
+	}
+}
+
+func (tb *Table) mergePartsOptimal(pws []*partWrapper, stopCh <-chan struct{}) error {
 	for len(pws) > defaultPartsToMerge {
-		if err := tb.mergeParts(pws[:defaultPartsToMerge], nil, false); err != nil {
+		if err := tb.mergeParts(pws[:defaultPartsToMerge], stopCh, false); err != nil {
 			return fmt.Errorf("cannot merge %d parts: %s", defaultPartsToMerge, err)
 		}
 		pws = pws[defaultPartsToMerge:]
 	}
 	if len(pws) > 0 {
-		if err := tb.mergeParts(pws, nil, false); err != nil {
+		if err := tb.mergeParts(pws, stopCh, false); err != nil {
 			return fmt.Errorf("cannot merge %d parts: %s", len(pws), err)
 		}
 	}
@@ -477,7 +552,7 @@ func (tb *Table) mergeRawItemsBlocks(blocksToMerge []*inmemoryBlock) {
 		}
 
 		// The added part exceeds maxParts count. Assist with merging other parts.
-		err := tb.mergeSmallParts(false)
+		err := tb.mergeExistingParts(false)
 		if err == nil {
 			atomic.AddUint64(&tb.assistedMerges, 1)
 			continue
@@ -541,7 +616,7 @@ func (tb *Table) mergeInmemoryBlocks(blocksToMerge []*inmemoryBlock) *partWrappe
 	// Merge parts.
 	// The merge shouldn't be interrupted by stopCh,
 	// since it may be final after stopCh is closed.
-	if err := mergeBlockStreams(&mpDst.ph, bsw, bsrs, nil, &tb.itemsMerged); err != nil {
+	if err := mergeBlockStreams(&mpDst.ph, bsw, bsrs, tb.prepareBlock, nil, &tb.itemsMerged); err != nil {
 		logger.Panicf("FATAL: cannot merge inmemoryBlocks: %s", err)
 	}
 	putBlockStreamWriter(bsw)
@@ -558,7 +633,7 @@ func (tb *Table) mergeInmemoryBlocks(blocksToMerge []*inmemoryBlock) *partWrappe
 }
 
 func (tb *Table) startPartMergers() {
-	for i := 0; i < mergeWorkers; i++ {
+	for i := 0; i < mergeWorkersCount; i++ {
 		tb.partMergersWG.Add(1)
 		go func() {
 			if err := tb.partMerger(); err != nil {
@@ -569,7 +644,7 @@ func (tb *Table) startPartMergers() {
 	}
 }
 
-func (tb *Table) mergeSmallParts(isFinal bool) error {
+func (tb *Table) mergeExistingParts(isFinal bool) error {
 	maxItems := tb.maxOutPartItems()
 	if maxItems > maxItemsPerPart {
 		maxItems = maxItemsPerPart
@@ -593,7 +668,7 @@ func (tb *Table) partMerger() error {
 	isFinal := false
 	t := time.NewTimer(sleepTime)
 	for {
-		err := tb.mergeSmallParts(isFinal)
+		err := tb.mergeExistingParts(isFinal)
 		if err == nil {
 			// Try merging additional parts.
 			sleepTime = minMergeSleepTime
@@ -608,7 +683,7 @@ func (tb *Table) partMerger() error {
 		if err != errNothingToMerge {
 			return err
 		}
-		if time.Since(lastMergeTime) > 10*time.Second {
+		if time.Since(lastMergeTime) > 30*time.Second {
 			// We have free time for merging into bigger parts.
 			// This should improve select performance.
 			lastMergeTime = time.Now()
@@ -700,7 +775,7 @@ func (tb *Table) mergeParts(pws []*partWrapper, stopCh <-chan struct{}, isOuterP
 
 	// Merge parts into a temporary location.
 	var ph partHeader
-	err := mergeBlockStreams(&ph, bsw, bsrs, stopCh, &tb.itemsMerged)
+	err := mergeBlockStreams(&ph, bsw, bsrs, tb.prepareBlock, stopCh, &tb.itemsMerged)
 	putBlockStreamWriter(bsw)
 	if err != nil {
 		if err == errForciblyStopped {
@@ -826,17 +901,20 @@ func (tb *Table) maxOutPartItemsSlow() uint64 {
 
 	// Calculate the maximum number of items in the output merge part
 	// by dividing the freeSpace by 4 and by the number of concurrent
-	// mergeWorkers.
+	// mergeWorkersCount.
 	// This assumes each item is compressed into 4 bytes.
-	return freeSpace / uint64(mergeWorkers) / 4
+	return freeSpace / uint64(mergeWorkersCount) / 4
 }
 
-var mergeWorkers = func() int {
+var mergeWorkersCount = func() int {
 	return runtime.GOMAXPROCS(-1)
 }()
 
 func openParts(path string) ([]*partWrapper, error) {
-	// Verify that the directory for the parts exists.
+	// The path can be missing after restoring from backup, so create it if needed.
+	if err := fs.MkdirAllIfNotExist(path); err != nil {
+		return nil, err
+	}
 	d, err := os.Open(path)
 	if err != nil {
 		return nil, fmt.Errorf("cannot open difrectory: %s", err)
@@ -950,11 +1028,20 @@ func (tb *Table) CreateSnapshotAt(dstDir string) error {
 		return fmt.Errorf("cannot read directory: %s", err)
 	}
 	for _, fi := range fis {
+		fn := fi.Name()
 		if !fs.IsDirOrSymlink(fi) {
-			// Skip non-directories.
+			switch fn {
+			case convertToV1280FileName:
+				srcPath := srcDir + "/" + fn
+				dstPath := dstDir + "/" + fn
+				if err := os.Link(srcPath, dstPath); err != nil {
+					return fmt.Errorf("cannot hard link from %q to %q: %s", srcPath, dstPath, err)
+				}
+			default:
+				// Skip other non-directories.
+			}
 			continue
 		}
-		fn := fi.Name()
 		if isSpecialDir(fn) {
 			// Skip special dirs.
 			continue
@@ -1162,30 +1249,31 @@ func appendPartsToMerge(dst, src []*partWrapper, maxPartsToMerge int, maxItems u
 	for i := 2; i <= n; i++ {
 		for j := 0; j <= len(src)-i; j++ {
 			itemsSum := uint64(0)
-			for _, pw := range src[j : j+i] {
+			a := src[j : j+i]
+			for _, pw := range a {
 				itemsSum += pw.p.ph.itemsCount
 			}
 			if itemsSum > maxItems {
-				continue
+				// There is no sense in checking the remaining bigger parts.
+				break
 			}
-			m := float64(itemsSum) / float64(src[j+i-1].p.ph.itemsCount)
+			m := float64(itemsSum) / float64(a[len(a)-1].p.ph.itemsCount)
 			if m < maxM {
 				continue
 			}
 			maxM = m
-			pws = src[j : j+i]
+			pws = a
 		}
 	}
 
-	minM := float64(maxPartsToMerge / 2)
-	if minM < 2 {
-		minM = 2
+	minM := float64(maxPartsToMerge) / 2
+	if minM < 1.7 {
+		minM = 1.7
 	}
 	if maxM < minM {
 		// There is no sense in merging parts with too small m.
 		return dst
 	}
-
 	return append(dst, pws...)
 }
 

lib/mergeset/table_search.go

@@ -58,7 +58,7 @@ func (ts *TableSearch) reset() {
 // Init initializes ts for searching in the tb.
 //
 // MustClose must be called when the ts is no longer needed.
-func (ts *TableSearch) Init(tb *Table) {
+func (ts *TableSearch) Init(tb *Table, shouldCacheBlock func(item []byte) bool) {
 	if ts.needClosing {
 		logger.Panicf("BUG: missing MustClose call before the next call to Init")
 	}
@@ -76,7 +76,7 @@ func (ts *TableSearch) Init(tb *Table) {
 	}
 	ts.psPool = ts.psPool[:len(ts.pws)]
 	for i, pw := range ts.pws {
-		ts.psPool[i].Init(pw.p)
+		ts.psPool[i].Init(pw.p, shouldCacheBlock)
 	}
 }
 

lib/mergeset/table_search_test.go

@@ -40,7 +40,7 @@ func TestTableSearchSerial(t *testing.T) {
 
 	func() {
 		// Re-open the table and verify the search works.
-		tb, err := OpenTable(path, nil)
+		tb, err := OpenTable(path, nil, nil)
 		if err != nil {
 			t.Fatalf("cannot open table: %s", err)
 		}
@@ -75,7 +75,7 @@ func TestTableSearchConcurrent(t *testing.T) {
 
 	// Re-open the table and verify the search works.
 	func() {
-		tb, err := OpenTable(path, nil)
+		tb, err := OpenTable(path, nil, nil)
 		if err != nil {
 			t.Fatalf("cannot open table: %s", err)
 		}
@@ -109,7 +109,7 @@ func testTableSearchConcurrent(tb *Table, items []string) error {
 
 func testTableSearchSerial(tb *Table, items []string) error {
 	var ts TableSearch
-	ts.Init(tb)
+	ts.Init(tb, nil)
 	for _, key := range []string{
 		"",
 		"123",
@@ -151,7 +151,7 @@ func newTestTable(path string, itemsCount int) (*Table, []string, error) {
 	flushCallback := func() {
 		atomic.AddUint64(&flushes, 1)
 	}
-	tb, err := OpenTable(path, flushCallback)
+	tb, err := OpenTable(path, flushCallback, nil)
 	if err != nil {
 		return nil, nil, fmt.Errorf("cannot open table: %s", err)
 	}

lib/mergeset/table_search_timing_test.go

@@ -32,7 +32,7 @@ func benchmarkTableSearch(b *testing.B, itemsCount int) {
 
 	// Force finishing pending merges
 	tb.MustClose()
-	tb, err = OpenTable(path, nil)
+	tb, err = OpenTable(path, nil, nil)
 	if err != nil {
 		b.Fatalf("unexpected error when re-opening table %q: %s", path, err)
 	}
@@ -81,7 +81,7 @@ func benchmarkTableSearchKeysExt(b *testing.B, tb *Table, keys [][]byte, stripSu
 	b.SetBytes(int64(searchKeysCount * rowsToScan))
 	b.RunParallel(func(pb *testing.PB) {
 		var ts TableSearch
-		ts.Init(tb)
+		ts.Init(tb, nil)
 		defer ts.MustClose()
 		for pb.Next() {
 			startIdx := rand.Intn(len(keys) - searchKeysCount)

lib/mergeset/table_test.go

@@ -21,7 +21,7 @@ func TestTableOpenClose(t *testing.T) {
 	}()
 
 	// Create a new table
-	tb, err := OpenTable(path, nil)
+	tb, err := OpenTable(path, nil, nil)
 	if err != nil {
 		t.Fatalf("cannot create new table: %s", err)
 	}
@@ -31,7 +31,7 @@ func TestTableOpenClose(t *testing.T) {
 
 	// Re-open created table multiple times.
 	for i := 0; i < 10; i++ {
-		tb, err := OpenTable(path, nil)
+		tb, err := OpenTable(path, nil, nil)
 		if err != nil {
 			t.Fatalf("cannot open created table: %s", err)
 		}
@@ -45,14 +45,14 @@ func TestTableOpenMultipleTimes(t *testing.T) {
 		_ = os.RemoveAll(path)
 	}()
 
-	tb1, err := OpenTable(path, nil)
+	tb1, err := OpenTable(path, nil, nil)
 	if err != nil {
 		t.Fatalf("cannot open table: %s", err)
 	}
 	defer tb1.MustClose()
 
 	for i := 0; i < 10; i++ {
-		tb2, err := OpenTable(path, nil)
+		tb2, err := OpenTable(path, nil, nil)
 		if err == nil {
 			tb2.MustClose()
 			t.Fatalf("expecting non-nil error when opening already opened table")
@@ -73,7 +73,7 @@ func TestTableAddItemSerial(t *testing.T) {
 	flushCallback := func() {
 		atomic.AddUint64(&flushes, 1)
 	}
-	tb, err := OpenTable(path, flushCallback)
+	tb, err := OpenTable(path, flushCallback, nil)
 	if err != nil {
 		t.Fatalf("cannot open %q: %s", path, err)
 	}
@@ -99,7 +99,7 @@ func TestTableAddItemSerial(t *testing.T) {
 	testReopenTable(t, path, itemsCount)
 
 	// Add more items in order to verify merge between inmemory parts and file-based parts.
-	tb, err = OpenTable(path, nil)
+	tb, err = OpenTable(path, nil, nil)
 	if err != nil {
 		t.Fatalf("cannot open %q: %s", path, err)
 	}
@@ -132,7 +132,7 @@ func TestTableCreateSnapshotAt(t *testing.T) {
 		_ = os.RemoveAll(path)
 	}()
 
-	tb, err := OpenTable(path, nil)
+	tb, err := OpenTable(path, nil, nil)
 	if err != nil {
 		t.Fatalf("cannot open %q: %s", path, err)
 	}
@@ -163,23 +163,23 @@ func TestTableCreateSnapshotAt(t *testing.T) {
 	}()
 
 	// Verify snapshots contain all the data.
-	tb1, err := OpenTable(snapshot1, nil)
+	tb1, err := OpenTable(snapshot1, nil, nil)
 	if err != nil {
 		t.Fatalf("cannot open %q: %s", path, err)
 	}
 	defer tb1.MustClose()
 
-	tb2, err := OpenTable(snapshot2, nil)
+	tb2, err := OpenTable(snapshot2, nil, nil)
 	if err != nil {
 		t.Fatalf("cannot open %q: %s", path, err)
 	}
 	defer tb2.MustClose()
 
 	var ts, ts1, ts2 TableSearch
-	ts.Init(tb)
-	ts1.Init(tb1)
+	ts.Init(tb, nil)
+	ts1.Init(tb1, nil)
 	defer ts1.MustClose()
-	ts2.Init(tb2)
+	ts2.Init(tb2, nil)
 	defer ts2.MustClose()
 	for i := 0; i < itemsCount; i++ {
 		key := []byte(fmt.Sprintf("item %d", i))
@@ -217,7 +217,12 @@ func TestTableAddItemsConcurrent(t *testing.T) {
 	flushCallback := func() {
 		atomic.AddUint64(&flushes, 1)
 	}
-	tb, err := OpenTable(path, flushCallback)
+	var itemsMerged uint64
+	prepareBlock := func(data []byte, items [][]byte) ([]byte, [][]byte) {
+		atomic.AddUint64(&itemsMerged, uint64(len(items)))
+		return data, items
+	}
+	tb, err := OpenTable(path, flushCallback, prepareBlock)
 	if err != nil {
 		t.Fatalf("cannot open %q: %s", path, err)
 	}
@@ -230,6 +235,10 @@ func TestTableAddItemsConcurrent(t *testing.T) {
 	if atomic.LoadUint64(&flushes) == 0 {
 		t.Fatalf("unexpected zero flushes")
 	}
+	n := atomic.LoadUint64(&itemsMerged)
+	if n < itemsCount {
+		t.Fatalf("too low number of items merged; got %v; must be at least %v", n, itemsCount)
+	}
 
 	var m TableMetrics
 	tb.UpdateMetrics(&m)
@@ -243,7 +252,7 @@ func TestTableAddItemsConcurrent(t *testing.T) {
 	testReopenTable(t, path, itemsCount)
 
 	// Add more items in order to verify merge between inmemory parts and file-based parts.
-	tb, err = OpenTable(path, nil)
+	tb, err = OpenTable(path, nil, nil)
 	if err != nil {
 		t.Fatalf("cannot open %q: %s", path, err)
 	}
@@ -285,7 +294,7 @@ func testReopenTable(t *testing.T, path string, itemsCount int) {
 	t.Helper()
 
 	for i := 0; i < 10; i++ {
-		tb, err := OpenTable(path, nil)
+		tb, err := OpenTable(path, nil, nil)
 		if err != nil {
 			t.Fatalf("cannot re-open %q: %s", path, err)
 		}

lib/netutil/conn.go

@@ -43,6 +43,11 @@ func (cm *connMetrics) init(group, name, addr string) {
 }
 
 type statConn struct {
+	// Move atomic counters to the top of struct in order to properly align them on 32-bit arch.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212
+
+	closeCalls uint64
+
 	readTimeout  time.Duration
 	lastReadTime time.Time
 
@@ -52,8 +57,6 @@ type statConn struct {
 	net.Conn
 
 	cm *connMetrics
-
-	closeCalls uint64
 }
 
 func (sc *statConn) Read(p []byte) (int, error) {

lib/prompb/README.md

@@ -1,14 +0,0 @@
-The compiled protobufs are version controlled and you won't normally need to
-re-compile them when building Prometheus.
-
-If however you have modified the defs and do need to re-compile, run
-`./scripts/genproto.sh` from the parent dir.
-
-In order for the script to run, you'll need `protoc` (version 3.5) in your
-PATH, and the following Go packages installed:
-
-- github.com/gogo/protobuf
-- github.com/gogo/protobuf/protoc-gen-gogofast
-- github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/
-- github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger
-- golang.org/x/tools/cmd/goimports

lib/storage/block_stream_reader.go

@@ -25,9 +25,13 @@ type blockStreamReader struct {
 
 	ph partHeader
 
-	timestampsReader filestream.ReadCloser
-	valuesReader     filestream.ReadCloser
-	indexReader      filestream.ReadCloser
+	// Use io.Reader type for timestampsReader and valuesReader
+	// in order to remove I2I conversion in readBlock
+	// when passing them to fs.ReadFullData
+	timestampsReader io.Reader
+	valuesReader     io.Reader
+
+	indexReader filestream.ReadCloser
 
 	mrs []metaindexRow
 
@@ -56,6 +60,11 @@ type blockStreamReader struct {
 	err error
 }
 
+func (bsr *blockStreamReader) assertWriteClosers() {
+	_ = bsr.timestampsReader.(filestream.ReadCloser)
+	_ = bsr.valuesReader.(filestream.ReadCloser)
+}
+
 func (bsr *blockStreamReader) reset() {
 	bsr.Block.Reset()
 
@@ -108,6 +117,8 @@ func (bsr *blockStreamReader) InitFromInmemoryPart(mp *inmemoryPart) {
 	if err != nil {
 		logger.Panicf("BUG: cannot unmarshal metaindex rows from inmemoryPart: %s", err)
 	}
+
+	bsr.assertWriteClosers()
 }
 
 // InitFromFilePart initializes bsr from a file-based part on the given path.
@@ -167,6 +178,8 @@ func (bsr *blockStreamReader) InitFromFilePart(path string) error {
 	bsr.indexReader = indexFile
 	bsr.mrs = mrs
 
+	bsr.assertWriteClosers()
+
 	return nil
 }
 
@@ -174,8 +187,8 @@ func (bsr *blockStreamReader) InitFromFilePart(path string) error {
 //
 // It closes *Reader files passed to Init.
 func (bsr *blockStreamReader) MustClose() {
-	bsr.timestampsReader.MustClose()
-	bsr.valuesReader.MustClose()
+	bsr.timestampsReader.(filestream.ReadCloser).MustClose()
+	bsr.valuesReader.(filestream.ReadCloser).MustClose()
 	bsr.indexReader.MustClose()
 
 	bsr.reset()

lib/storage/block_stream_reader_test.go

@@ -59,7 +59,7 @@ func TestBlockStreamReaderManyTSIDManyRows(t *testing.T) {
 	r.PrecisionBits = defaultPrecisionBits
 	const blocks = 123
 	for i := 0; i < 3210; i++ {
-		r.TSID.MetricID = uint64((1e12 - i) % blocks)
+		r.TSID.MetricID = uint64((1e9 - i) % blocks)
 		r.Value = rand.Float64()
 		r.Timestamp = int64(rand.Float64() * 1e9)
 		rows = append(rows, r)
@@ -73,7 +73,7 @@ func TestBlockStreamReaderReadConcurrent(t *testing.T) {
 	r.PrecisionBits = defaultPrecisionBits
 	const blocks = 123
 	for i := 0; i < 3210; i++ {
-		r.TSID.MetricID = uint64((1e12 - i) % blocks)
+		r.TSID.MetricID = uint64((1e9 - i) % blocks)
 		r.Value = rand.Float64()
 		r.Timestamp = int64(rand.Float64() * 1e9)
 		rows = append(rows, r)

lib/storage/block_stream_writer.go

@@ -2,6 +2,7 @@ package storage
 
 import (
 	"fmt"
+	"io"
 	"path/filepath"
 	"sync"
 	"sync/atomic"
@@ -17,10 +18,14 @@ type blockStreamWriter struct {
 	compressLevel int
 	path          string
 
-	timestampsWriter filestream.WriteCloser
-	valuesWriter     filestream.WriteCloser
-	indexWriter      filestream.WriteCloser
-	metaindexWriter  filestream.WriteCloser
+	// Use io.Writer type for timestampsWriter and valuesWriter
+	// in order to remove I2I conversion in WriteExternalBlock
+	// when passing them to fs.MustWriteData
+	timestampsWriter io.Writer
+	valuesWriter     io.Writer
+
+	indexWriter     filestream.WriteCloser
+	metaindexWriter filestream.WriteCloser
 
 	mr metaindexRow
 
@@ -35,6 +40,11 @@ type blockStreamWriter struct {
 	compressedMetaindexData []byte
 }
 
+func (bsw *blockStreamWriter) assertWriteClosers() {
+	_ = bsw.timestampsWriter.(filestream.WriteCloser)
+	_ = bsw.valuesWriter.(filestream.WriteCloser)
+}
+
 // Init initializes bsw with the given writers.
 func (bsw *blockStreamWriter) reset() {
 	bsw.compressLevel = 0
@@ -67,6 +77,8 @@ func (bsw *blockStreamWriter) InitFromInmemoryPart(mp *inmemoryPart) {
 	bsw.valuesWriter = &mp.valuesData
 	bsw.indexWriter = &mp.indexData
 	bsw.metaindexWriter = &mp.metaindexData
+
+	bsw.assertWriteClosers()
 }
 
 // InitFromFilePart initializes bsw from a file-based part on the given path.
@@ -126,6 +138,8 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 	bsw.indexWriter = indexFile
 	bsw.metaindexWriter = metaindexFile
 
+	bsw.assertWriteClosers()
+
 	return nil
 }
 
@@ -141,8 +155,8 @@ func (bsw *blockStreamWriter) MustClose() {
 	fs.MustWriteData(bsw.metaindexWriter, bsw.compressedMetaindexData)
 
 	// Close writers.
-	bsw.timestampsWriter.MustClose()
-	bsw.valuesWriter.MustClose()
+	bsw.timestampsWriter.(filestream.WriteCloser).MustClose()
+	bsw.valuesWriter.(filestream.WriteCloser).MustClose()
 	bsw.indexWriter.MustClose()
 	bsw.metaindexWriter.MustClose()
 

lib/storage/index_db_test.go

@@ -12,9 +12,331 @@ import (
 	"time"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/encoding"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/workingsetcache"
 )
 
+func TestMergeTagToMetricIDsRows(t *testing.T) {
+	f := func(items []string, expectedItems []string) {
+		t.Helper()
+		var data []byte
+		var itemsB [][]byte
+		for _, item := range items {
+			data = append(data, item...)
+			itemsB = append(itemsB, data[len(data)-len(item):])
+		}
+		if err := checkItemsSorted(itemsB); err != nil {
+			t.Fatalf("source items aren't sorted: %s", err)
+		}
+		resultData, resultItemsB := mergeTagToMetricIDsRows(data, itemsB)
+		if len(resultItemsB) != len(expectedItems) {
+			t.Fatalf("unexpected len(resultItemsB); got %d; want %d", len(resultItemsB), len(expectedItems))
+		}
+		if err := checkItemsSorted(resultItemsB); err != nil {
+			t.Fatalf("result items aren't sorted: %s", err)
+		}
+		for i, item := range resultItemsB {
+			if !bytes.HasPrefix(resultData, item) {
+				t.Fatalf("unexpected prefix for resultData #%d;\ngot\n%X\nwant\n%X", i, resultData, item)
+			}
+			resultData = resultData[len(item):]
+		}
+		if len(resultData) != 0 {
+			t.Fatalf("unexpected tail left in resultData: %X", resultData)
+		}
+		var resultItems []string
+		for _, item := range resultItemsB {
+			resultItems = append(resultItems, string(item))
+		}
+		if !reflect.DeepEqual(expectedItems, resultItems) {
+			t.Fatalf("unexpected items;\ngot\n%X\nwant\n%X", resultItems, expectedItems)
+		}
+	}
+	x := func(key, value string, metricIDs []uint64) string {
+		dst := marshalCommonPrefix(nil, nsPrefixTagToMetricIDs)
+		t := &Tag{
+			Key:   []byte(key),
+			Value: []byte(value),
+		}
+		dst = t.Marshal(dst)
+		for _, metricID := range metricIDs {
+			dst = encoding.MarshalUint64(dst, metricID)
+		}
+		return string(dst)
+	}
+
+	f(nil, nil)
+	f([]string{}, nil)
+	f([]string{"foo"}, []string{"foo"})
+	f([]string{"a", "b", "c", "def"}, []string{"a", "b", "c", "def"})
+	f([]string{"\x00", "\x00b", "\x00c", "\x00def"}, []string{"\x00", "\x00b", "\x00c", "\x00def"})
+	f([]string{
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+	}, []string{
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+	})
+	f([]string{
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		"xyz",
+	}, []string{
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		"xyz",
+	})
+	f([]string{
+		"\x00asdf",
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+	}, []string{
+		"\x00asdf",
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+	})
+	f([]string{
+		"\x00asdf",
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		x("", "", []uint64{0}),
+		"xyz",
+	}, []string{
+		"\x00asdf",
+		x("", "", []uint64{0}),
+		"xyz",
+	})
+	f([]string{
+		"\x00asdf",
+		x("", "", []uint64{1}),
+		x("", "", []uint64{2}),
+		x("", "", []uint64{3}),
+		x("", "", []uint64{4}),
+		"xyz",
+	}, []string{
+		"\x00asdf",
+		x("", "", []uint64{1, 2, 3, 4}),
+		"xyz",
+	})
+	f([]string{
+		"\x00asdf",
+		x("", "", []uint64{1}),
+		x("", "", []uint64{2}),
+		x("", "", []uint64{3}),
+		x("", "", []uint64{4}),
+	}, []string{
+		"\x00asdf",
+		x("", "", []uint64{1, 2, 3}),
+		x("", "", []uint64{4}),
+	})
+	f([]string{
+		"\x00asdf",
+		x("", "", []uint64{1}),
+		x("", "", []uint64{2, 3, 4}),
+		x("", "", []uint64{2, 3, 4, 5}),
+		x("", "", []uint64{3, 5}),
+		"foo",
+	}, []string{
+		"\x00asdf",
+		x("", "", []uint64{1, 2, 3, 4, 5}),
+		"foo",
+	})
+	f([]string{
+		"\x00asdf",
+		x("", "", []uint64{1}),
+		x("", "a", []uint64{2, 3, 4}),
+		x("", "a", []uint64{2, 3, 4, 5}),
+		x("", "b", []uint64{3, 5}),
+		"foo",
+	}, []string{
+		"\x00asdf",
+		x("", "", []uint64{1}),
+		x("", "a", []uint64{2, 3, 4, 5}),
+		x("", "b", []uint64{3, 5}),
+		"foo",
+	})
+	f([]string{
+		"\x00asdf",
+		x("", "", []uint64{1}),
+		x("x", "a", []uint64{2, 3, 4}),
+		x("y", "", []uint64{2, 3, 4, 5}),
+		x("y", "x", []uint64{3, 5}),
+		"foo",
+	}, []string{
+		"\x00asdf",
+		x("", "", []uint64{1}),
+		x("x", "a", []uint64{2, 3, 4}),
+		x("y", "", []uint64{2, 3, 4, 5}),
+		x("y", "x", []uint64{3, 5}),
+		"foo",
+	})
+	f([]string{
+		"\x00asdf",
+		x("sdf", "aa", []uint64{1, 1, 3}),
+		x("sdf", "aa", []uint64{1, 2}),
+		"foo",
+	}, []string{
+		"\x00asdf",
+		x("sdf", "aa", []uint64{1, 2, 3}),
+		"foo",
+	})
+	f([]string{
+		"\x00asdf",
+		x("sdf", "aa", []uint64{1, 2, 2, 4}),
+		x("sdf", "aa", []uint64{1, 2, 3}),
+		"foo",
+	}, []string{
+		"\x00asdf",
+		x("sdf", "aa", []uint64{1, 2, 3, 4}),
+		"foo",
+	})
+
+	// Construct big source chunks
+	var metricIDs []uint64
+
+	metricIDs = metricIDs[:0]
+	for i := 0; i < maxMetricIDsPerRow-1; i++ {
+		metricIDs = append(metricIDs, uint64(i))
+	}
+	f([]string{
+		"\x00aa",
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", metricIDs),
+		"x",
+	}, []string{
+		"\x00aa",
+		x("foo", "bar", metricIDs),
+		"x",
+	})
+
+	metricIDs = metricIDs[:0]
+	for i := 0; i < maxMetricIDsPerRow; i++ {
+		metricIDs = append(metricIDs, uint64(i))
+	}
+	f([]string{
+		"\x00aa",
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", metricIDs),
+		"x",
+	}, []string{
+		"\x00aa",
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", metricIDs),
+		"x",
+	})
+
+	metricIDs = metricIDs[:0]
+	for i := 0; i < 3*maxMetricIDsPerRow; i++ {
+		metricIDs = append(metricIDs, uint64(i))
+	}
+	f([]string{
+		"\x00aa",
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", metricIDs),
+		"x",
+	}, []string{
+		"\x00aa",
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", metricIDs),
+		"x",
+	})
+	f([]string{
+		"\x00aa",
+		x("foo", "bar", []uint64{0, 0, 1, 2, 3}),
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", metricIDs),
+		"x",
+	}, []string{
+		"\x00aa",
+		x("foo", "bar", []uint64{0, 1, 2, 3}),
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", metricIDs),
+		"x",
+	})
+
+	// Check for duplicate metricIDs removal
+	metricIDs = metricIDs[:0]
+	for i := 0; i < maxMetricIDsPerRow-1; i++ {
+		metricIDs = append(metricIDs, 123)
+	}
+	f([]string{
+		"\x00aa",
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", metricIDs),
+		"x",
+	}, []string{
+		"\x00aa",
+		x("foo", "bar", []uint64{123}),
+		"x",
+	})
+
+	// Check fallback to the original items after merging, which result in incorrect ordering.
+	metricIDs = metricIDs[:0]
+	for i := 0; i < maxMetricIDsPerRow-3; i++ {
+		metricIDs = append(metricIDs, uint64(123))
+	}
+	f([]string{
+		"\x00aa",
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", []uint64{123, 123, 125}),
+		x("foo", "bar", []uint64{123, 124}),
+		"x",
+	}, []string{
+		"\x00aa",
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", []uint64{123, 123, 125}),
+		x("foo", "bar", []uint64{123, 124}),
+		"x",
+	})
+	f([]string{
+		"\x00aa",
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", []uint64{123, 123, 125}),
+		x("foo", "bar", []uint64{123, 124}),
+	}, []string{
+		"\x00aa",
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", []uint64{123, 123, 125}),
+		x("foo", "bar", []uint64{123, 124}),
+	})
+	f([]string{
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", []uint64{123, 123, 125}),
+		x("foo", "bar", []uint64{123, 124}),
+	}, []string{
+		x("foo", "bar", metricIDs),
+		x("foo", "bar", []uint64{123, 123, 125}),
+		x("foo", "bar", []uint64{123, 124}),
+	})
+}
+
+func TestRemoveDuplicateMetricIDs(t *testing.T) {
+	f := func(metricIDs, expectedMetricIDs []uint64) {
+		t.Helper()
+		a := removeDuplicateMetricIDs(metricIDs)
+		if !reflect.DeepEqual(a, expectedMetricIDs) {
+			t.Fatalf("unexpected result from removeDuplicateMetricIDs:\ngot\n%d\nwant\n%d", a, expectedMetricIDs)
+		}
+	}
+	f(nil, nil)
+	f([]uint64{123}, []uint64{123})
+	f([]uint64{123, 123}, []uint64{123})
+	f([]uint64{123, 123, 123}, []uint64{123})
+	f([]uint64{123, 1234, 1235}, []uint64{123, 1234, 1235})
+	f([]uint64{0, 1, 1, 2}, []uint64{0, 1, 2})
+	f([]uint64{0, 0, 0, 1, 1, 2}, []uint64{0, 1, 2})
+	f([]uint64{0, 1, 1, 2, 2}, []uint64{0, 1, 2})
+	f([]uint64{0, 1, 2, 2}, []uint64{0, 1, 2})
+}
+
 func TestMarshalUnmarshalTSIDs(t *testing.T) {
 	f := func(tsids []TSID) {
 		t.Helper()
@@ -280,6 +602,7 @@ func testIndexDBGetOrCreateTSIDByName(db *indexDB, accountsCount, projectsCount,
 	is := db.getIndexSearch()
 	defer db.putIndexSearch(is)
 
+	var metricNameBuf []byte
 	for i := 0; i < 4e2+1; i++ {
 		var mn MetricName
 
@@ -294,11 +617,11 @@ func testIndexDBGetOrCreateTSIDByName(db *indexDB, accountsCount, projectsCount,
 			mn.AddTag(key, value)
 		}
 		mn.sortTags()
-		metricName := mn.Marshal(nil)
+		metricNameBuf = mn.Marshal(metricNameBuf[:0])
 
 		// Create tsid for the metricName.
 		var tsid TSID
-		if err := is.GetOrCreateTSIDByName(&tsid, metricName); err != nil {
+		if err := is.GetOrCreateTSIDByName(&tsid, metricNameBuf); err != nil {
 			return nil, nil, fmt.Errorf("unexpected error when creating tsid for mn:\n%s: %s", &mn, err)
 		}
 
@@ -306,22 +629,22 @@ func testIndexDBGetOrCreateTSIDByName(db *indexDB, accountsCount, projectsCount,
 		tsids = append(tsids, tsid)
 	}
 
+	// 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 nil, nil, fmt.Errorf("error in storeDateMetricID(%d, %d): %s", date, tsid.MetricID, err)
+		}
+	}
+
+	// Flush index to disk, so it becomes visible for search
 	db.tb.DebugFlush()
 
 	return mns, tsids, nil
 }
 
 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 {
@@ -361,7 +684,7 @@ func testIndexDBCheckTSIDByName(db *indexDB, mns []MetricName, tsids []TSID, isC
 		var err error
 		metricNameCopy, err = db.searchMetricName(metricNameCopy[:0], tsidCopy.MetricID)
 		if err != nil {
-			return fmt.Errorf("error in searchMetricName: %s", err)
+			return fmt.Errorf("error in searchMetricName for metricID=%d; i=%d: %s", tsidCopy.MetricID, i, err)
 		}
 		if !bytes.Equal(metricName, metricNameCopy) {
 			return fmt.Errorf("unexpected mn for metricID=%d;\ngot\n%q\nwant\n%q", tsidCopy.MetricID, metricNameCopy, metricName)
@@ -451,7 +774,7 @@ func testIndexDBCheckTSIDByName(db *indexDB, mns []MetricName, tsids []TSID, isC
 			return fmt.Errorf("cannot search by exact tag filter: %s", err)
 		}
 		if !testHasTSID(tsidsFound, tsid) {
-			return fmt.Errorf("tsids is missing in exact tsidsFound\ntsid=%+v\ntsidsFound=%+v\ntfs=%s\nmn=%s", tsid, tsidsFound, tfs, mn)
+			return fmt.Errorf("tsids is missing in exact tsidsFound\ntsid=%+v\ntsidsFound=%+v\ntfs=%s\nmn=%s\ni=%d", tsid, tsidsFound, tfs, mn, i)
 		}
 
 		// Verify tag cache.

lib/storage/merge.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/decimal"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/uint64set"
 )
 
 // mergeBlockStreams merges bsrs into bsw and updates ph.
@@ -14,7 +15,7 @@ import (
 //
 // rowsMerged is atomically updated with the number of merged rows during the merge.
 func mergeBlockStreams(ph *partHeader, bsw *blockStreamWriter, bsrs []*blockStreamReader, stopCh <-chan struct{}, rowsMerged *uint64,
-	deletedMetricIDs map[uint64]struct{}, rowsDeleted *uint64) error {
+	deletedMetricIDs *uint64set.Set, rowsDeleted *uint64) error {
 	ph.Reset()
 
 	bsm := bsmPool.Get().(*blockStreamMerger)
@@ -41,7 +42,7 @@ var bsmPool = &sync.Pool{
 var errForciblyStopped = fmt.Errorf("forcibly stopped")
 
 func mergeBlockStreamsInternal(ph *partHeader, bsw *blockStreamWriter, bsm *blockStreamMerger, stopCh <-chan struct{}, rowsMerged *uint64,
-	deletedMetricIDs map[uint64]struct{}, rowsDeleted *uint64) error {
+	deletedMetricIDs *uint64set.Set, rowsDeleted *uint64) error {
 	// Search for the first block to merge
 	var pendingBlock *Block
 	for bsm.NextBlock() {
@@ -50,7 +51,7 @@ func mergeBlockStreamsInternal(ph *partHeader, bsw *blockStreamWriter, bsm *bloc
 			return errForciblyStopped
 		default:
 		}
-		if _, deleted := deletedMetricIDs[bsm.Block.bh.TSID.MetricID]; deleted {
+		if deletedMetricIDs.Has(bsm.Block.bh.TSID.MetricID) {
 			// Skip blocks for deleted metrics.
 			*rowsDeleted += uint64(bsm.Block.bh.RowsCount)
 			continue
@@ -72,7 +73,7 @@ func mergeBlockStreamsInternal(ph *partHeader, bsw *blockStreamWriter, bsm *bloc
 			return errForciblyStopped
 		default:
 		}
-		if _, deleted := deletedMetricIDs[bsm.Block.bh.TSID.MetricID]; deleted {
+		if deletedMetricIDs.Has(bsm.Block.bh.TSID.MetricID) {
 			// Skip blocks for deleted metrics.
 			*rowsDeleted += uint64(bsm.Block.bh.RowsCount)
 			continue

lib/storage/merge_test.go

@@ -25,7 +25,7 @@ func TestMergeBlockStreamsOneStreamOneBlockManyRows(t *testing.T) {
 	minTimestamp := int64(1<<63 - 1)
 	maxTimestamp := int64(-1 << 63)
 	for i := 0; i < maxRowsPerBlock; i++ {
-		r.Timestamp = int64(rand.Intn(1e15))
+		r.Timestamp = int64(rand.Intn(1e9))
 		r.Value = rand.NormFloat64() * 2332
 		rows = append(rows, r)
 
@@ -51,7 +51,7 @@ func TestMergeBlockStreamsOneStreamManyBlocksOneRow(t *testing.T) {
 	for i := 0; i < blocksCount; i++ {
 		initTestTSID(&r.TSID)
 		r.TSID.MetricID = uint64(i * 123)
-		r.Timestamp = int64(rand.Intn(1e15))
+		r.Timestamp = int64(rand.Intn(1e9))
 		r.Value = rand.NormFloat64() * 2332
 		rows = append(rows, r)
 
@@ -78,7 +78,7 @@ func TestMergeBlockStreamsOneStreamManyBlocksManyRows(t *testing.T) {
 	maxTimestamp := int64(-1 << 63)
 	for i := 0; i < rowsCount; i++ {
 		r.TSID.MetricID = uint64(i % blocksCount)
-		r.Timestamp = int64(rand.Intn(1e15))
+		r.Timestamp = int64(rand.Intn(1e9))
 		r.Value = rand.NormFloat64() * 2332
 		rows = append(rows, r)
 
@@ -175,7 +175,7 @@ func TestMergeBlockStreamsTwoStreamsManyBlocksManyRows(t *testing.T) {
 	const rowsCount1 = 4938
 	for i := 0; i < rowsCount1; i++ {
 		r.TSID.MetricID = uint64(i % blocksCount)
-		r.Timestamp = int64(rand.Intn(1e15))
+		r.Timestamp = int64(rand.Intn(1e9))
 		r.Value = rand.NormFloat64() * 2332
 		rows = append(rows, r)
 
@@ -192,7 +192,7 @@ func TestMergeBlockStreamsTwoStreamsManyBlocksManyRows(t *testing.T) {
 	const rowsCount2 = 3281
 	for i := 0; i < rowsCount2; i++ {
 		r.TSID.MetricID = uint64((i + 17) % blocksCount)
-		r.Timestamp = int64(rand.Intn(1e15))
+		r.Timestamp = int64(rand.Intn(1e9))
 		r.Value = rand.NormFloat64() * 2332
 		rows = append(rows, r)
 
@@ -310,7 +310,7 @@ func TestMergeBlockStreamsManyStreamsManyBlocksManyRows(t *testing.T) {
 		var rows []rawRow
 		for j := 0; j < rowsPerStream; j++ {
 			r.TSID.MetricID = uint64(j % blocksCount)
-			r.Timestamp = int64(rand.Intn(1e10))
+			r.Timestamp = int64(rand.Intn(1e9))
 			r.Value = rand.NormFloat64()
 			rows = append(rows, r)
 
@@ -343,7 +343,7 @@ func TestMergeForciblyStop(t *testing.T) {
 		var rows []rawRow
 		for j := 0; j < rowsPerStream; j++ {
 			r.TSID.MetricID = uint64(j % blocksCount)
-			r.Timestamp = int64(rand.Intn(1e10))
+			r.Timestamp = int64(rand.Intn(1e9))
 			r.Value = rand.NormFloat64()
 			rows = append(rows, r)
 

lib/storage/metric_name.go

@@ -25,6 +25,17 @@ type Tag struct {
 	Value []byte
 }
 
+// Reset resets the tag.
+func (tag *Tag) Reset() {
+	tag.Key = tag.Key[:0]
+	tag.Value = tag.Value[:0]
+}
+
+// Equal returns true if tag equals t
+func (tag *Tag) Equal(t *Tag) bool {
+	return string(tag.Key) == string(t.Key) && string(tag.Value) == string(t.Value)
+}
+
 // Marshal appends marshaled tag to dst and returns the result.
 func (tag *Tag) Marshal(dst []byte) []byte {
 	dst = marshalTagValue(dst, tag.Key)

lib/storage/metric_name_test.go

@@ -142,3 +142,82 @@ func TestMetricNameMarshalUnmarshalRaw(t *testing.T) {
 		}
 	}
 }
+
+func TestMetricNameCopyFrom(t *testing.T) {
+	var from MetricName
+	from.MetricGroup = []byte("group")
+	from.AddTag("key", "value")
+
+	var to MetricName
+	to.CopyFrom(&from)
+
+	var expected MetricName
+	expected.MetricGroup = []byte("group")
+	expected.AddTag("key", "value")
+
+	if !reflect.DeepEqual(expected, to) {
+		t.Fatalf("expecting equal metics exp: %s, got %s", &expected, &to)
+	}
+}
+
+func TestMetricNameRemoveTagsOn(t *testing.T) {
+	var emptyMN MetricName
+	emptyMN.MetricGroup = []byte("name")
+	emptyMN.AddTag("key", "value")
+	emptyMN.RemoveTagsOn(nil)
+	if len(emptyMN.MetricGroup) != 0 || len(emptyMN.Tags) != 0 {
+		t.Fatalf("expecitng empty metric name got %s", &emptyMN)
+	}
+
+	var asIsMN MetricName
+	asIsMN.MetricGroup = []byte("name")
+	asIsMN.AddTag("key", "value")
+	asIsMN.RemoveTagsOn([]string{"__name__", "key"})
+	var expAsIsMN MetricName
+	expAsIsMN.MetricGroup = []byte("name")
+	expAsIsMN.AddTag("key", "value")
+	if !reflect.DeepEqual(expAsIsMN, asIsMN) {
+		t.Fatalf("expecitng %s got %s", &expAsIsMN, &asIsMN)
+	}
+
+	var mn MetricName
+	mn.MetricGroup = []byte("name")
+	mn.AddTag("foo", "bar")
+	mn.AddTag("baz", "qux")
+	mn.RemoveTagsOn([]string{"baz"})
+	var expMN MetricName
+	expMN.AddTag("baz", "qux")
+	if !reflect.DeepEqual(expMN.Tags, mn.Tags) || len(mn.MetricGroup) != len(expMN.MetricGroup) {
+		t.Fatalf("expecitng %s got %s", &expMN, &mn)
+	}
+}
+
+func TestMetricNameRemoveTag(t *testing.T) {
+	var mn MetricName
+	mn.MetricGroup = []byte("name")
+	mn.AddTag("foo", "bar")
+	mn.AddTag("baz", "qux")
+	mn.RemoveTag("__name__")
+	if len(mn.MetricGroup) != 0 {
+		t.Fatalf("expecting empty metric group got %s", &mn)
+	}
+	mn.RemoveTag("foo")
+	var expMN MetricName
+	expMN.AddTag("baz", "qux")
+	if !reflect.DeepEqual(expMN.Tags, mn.Tags) || len(mn.MetricGroup) != len(expMN.MetricGroup) {
+		t.Fatalf("expecitng %s got %s", &expMN, &mn)
+	}
+}
+
+func TestMetricNameRemoveTagsIgnoring(t *testing.T) {
+	var mn MetricName
+	mn.MetricGroup = []byte("name")
+	mn.AddTag("foo", "bar")
+	mn.AddTag("baz", "qux")
+	mn.RemoveTagsIgnoring([]string{"__name__", "foo"})
+	var expMN MetricName
+	expMN.AddTag("baz", "qux")
+	if !reflect.DeepEqual(expMN.Tags, mn.Tags) || len(mn.MetricGroup) != len(expMN.MetricGroup) {
+		t.Fatalf("expecitng %s got %s", &expMN, &mn)
+	}
+}

lib/storage/part.go

@@ -5,6 +5,7 @@ import (
 	"path/filepath"
 	"sync"
 	"sync/atomic"
+	"unsafe"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/filestream"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fs"
@@ -27,8 +28,7 @@ var (
 	maxCachedIndexBlocksPerPartOnce sync.Once
 )
 
-// part represents a searchable part containing time series data.
-type part struct {
+type partInternals struct {
 	ph partHeader
 
 	// Filesystem path to the part.
@@ -44,7 +44,15 @@ type part struct {
 	indexFile      fs.ReadAtCloser
 
 	metaindex []metaindexRow
+}
 
+// part represents a searchable part containing time series data.
+type part struct {
+	partInternals
+
+	// Align ibCache to 8 bytes in order to align internal counters on 32-bit architectures.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212
+	_       [(8 - (unsafe.Sizeof(partInternals{}) % 8)) % 8]byte
 	ibCache indexBlockCache
 }
 
@@ -107,27 +115,26 @@ func newPart(ph *partHeader, path string, size uint64, metaindexReader filestrea
 	}
 	metaindexReader.MustClose()
 
-	p := &part{
-		ph:             *ph,
-		path:           path,
-		size:           size,
-		timestampsFile: timestampsFile,
-		valuesFile:     valuesFile,
-		indexFile:      indexFile,
+	var p part
+	p.ph = *ph
+	p.path = path
+	p.size = size
+	p.timestampsFile = timestampsFile
+	p.valuesFile = valuesFile
+	p.indexFile = indexFile
 
-		metaindex: metaindex,
-	}
+	p.metaindex = metaindex
 
 	if len(errors) > 0 {
 		// Return only the first error, since it has no sense in returning all errors.
-		err = fmt.Errorf("cannot initialize part %q: %s", p, errors[0])
+		err = fmt.Errorf("cannot initialize part %q: %s", &p, errors[0])
 		p.MustClose()
 		return nil, err
 	}
 
 	p.ibCache.Init()
 
-	return p, nil
+	return &p, nil
 }
 
 // String returns human-readable representation of p.
@@ -168,12 +175,14 @@ func putIndexBlock(ib *indexBlock) {
 var indexBlockPool sync.Pool
 
 type indexBlockCache struct {
+	// Put atomic counters to the top of struct in order to align them to 8 bytes on 32-bit architectures.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212
+	requests uint64
+	misses   uint64
+
 	m         map[uint64]*indexBlock
 	missesMap map[uint64]uint64
 	mu        sync.RWMutex
-
-	requests uint64
-	misses   uint64
 }
 
 func (ibc *indexBlockCache) Init() {

lib/storage/part_search.go

@@ -3,7 +3,9 @@ package storage
 import (
 	"fmt"
 	"io"
+	"os"
 	"sort"
+	"strings"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/encoding"
@@ -49,7 +51,7 @@ type partSearch struct {
 func (ps *partSearch) reset() {
 	ps.Block.Reset()
 	ps.p = nil
-	ps.tsids = ps.tsids[:0]
+	ps.tsids = nil
 	ps.tsidIdx = 0
 	ps.fetchData = true
 	ps.metaindex = nil
@@ -64,16 +66,24 @@ func (ps *partSearch) reset() {
 	ps.err = nil
 }
 
+var isInTest = func() bool {
+	return strings.HasSuffix(os.Args[0], ".test")
+}()
+
 // Init initializes the ps with the given p, tsids and tr.
+//
+// tsids must be sorted.
+// tsids cannot be modified after the Init call, since it is owned by ps.
 func (ps *partSearch) Init(p *part, tsids []TSID, tr TimeRange, fetchData bool) {
 	ps.reset()
 	ps.p = p
 
 	if p.ph.MinTimestamp <= tr.MaxTimestamp && p.ph.MaxTimestamp >= tr.MinTimestamp {
-		if !sort.SliceIsSorted(tsids, func(i, j int) bool { return tsids[i].Less(&tsids[j]) }) {
+		if isInTest && !sort.SliceIsSorted(tsids, func(i, j int) bool { return tsids[i].Less(&tsids[j]) }) {
 			logger.Panicf("BUG: tsids must be sorted; got %+v", tsids)
 		}
-		ps.tsids = append(ps.tsids[:0], tsids...)
+		// take ownership of of tsids.
+		ps.tsids = tsids
 	}
 	ps.tr = tr
 	ps.fetchData = fetchData

lib/storage/partition.go

@@ -19,6 +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/uint64set"
 )
 
 func maxRowsPerSmallPart() uint64 {
@@ -28,7 +29,7 @@ func maxRowsPerSmallPart() uint64 {
 	// Production data shows that each row occupies ~1 byte in the compressed part.
 	// It is expected no more than defaultPartsToMerge/2 parts exist
 	// in the OS page cache before they are merged into bigger part.
-	// Halft of the remaining RAM must be left for lib/mergeset parts,
+	// Half of the remaining RAM must be left for lib/mergeset parts,
 	// so the maxItems is calculated using the below code:
 	maxRows := uint64(mem) / defaultPartsToMerge
 	if maxRows < 10e6 {
@@ -89,11 +90,27 @@ const inmemoryPartsFlushInterval = 5 * time.Second
 
 // partition represents a partition.
 type partition struct {
+	// Put atomic counters to the top of struct, so they are aligned to 8 bytes on 32-bit arch.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212
+
+	activeBigMerges   uint64
+	activeSmallMerges uint64
+	bigMergesCount    uint64
+	smallMergesCount  uint64
+	bigRowsMerged     uint64
+	smallRowsMerged   uint64
+	bigRowsDeleted    uint64
+	smallRowsDeleted  uint64
+
+	smallAssistedMerges uint64
+
+	mergeIdx uint64
+
 	smallPartsPath string
 	bigPartsPath   string
 
 	// The callack that returns deleted metric ids which must be skipped during merge.
-	getDeletedMetricIDs func() map[uint64]struct{}
+	getDeletedMetricIDs func() *uint64set.Set
 
 	// Name is the name of the partition in the form YYYY_MM.
 	name string
@@ -122,8 +139,6 @@ type partition struct {
 	// rawRowsLastFlushTime is the last time rawRows are flushed.
 	rawRowsLastFlushTime time.Time
 
-	mergeIdx uint64
-
 	snapshotLock sync.RWMutex
 
 	stopCh chan struct{}
@@ -132,30 +147,22 @@ type partition struct {
 	bigPartsMergerWG       sync.WaitGroup
 	rawRowsFlusherWG       sync.WaitGroup
 	inmemoryPartsFlusherWG sync.WaitGroup
-
-	activeBigMerges   uint64
-	activeSmallMerges uint64
-	bigMergesCount    uint64
-	smallMergesCount  uint64
-	bigRowsMerged     uint64
-	smallRowsMerged   uint64
-	bigRowsDeleted    uint64
-	smallRowsDeleted  uint64
-
-	smallAssistedMerges uint64
 }
 
 // partWrapper is a wrapper for the part.
 type partWrapper struct {
+	// Put atomic counters to the top of struct, so they are aligned to 8 bytes on 32-bit arch.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212
+
+	// The number of references to the part.
+	refCount uint64
+
 	// The part itself.
 	p *part
 
 	// non-nil if the part is inmemoryPart.
 	mp *inmemoryPart
 
-	// The number of references to the part.
-	refCount uint64
-
 	// Whether the part is in merge now.
 	isInMerge bool
 }
@@ -183,7 +190,7 @@ func (pw *partWrapper) decRef() {
 
 // createPartition creates new partition for the given timestamp and the given paths
 // to small and big partitions.
-func createPartition(timestamp int64, smallPartitionsPath, bigPartitionsPath string, getDeletedMetricIDs func() map[uint64]struct{}) (*partition, error) {
+func createPartition(timestamp int64, smallPartitionsPath, bigPartitionsPath string, getDeletedMetricIDs func() *uint64set.Set) (*partition, error) {
 	name := timestampToPartitionName(timestamp)
 	smallPartsPath := filepath.Clean(smallPartitionsPath) + "/" + name
 	bigPartsPath := filepath.Clean(bigPartitionsPath) + "/" + name
@@ -218,7 +225,7 @@ func (pt *partition) Drop() {
 }
 
 // openPartition opens the existing partition from the given paths.
-func openPartition(smallPartsPath, bigPartsPath string, getDeletedMetricIDs func() map[uint64]struct{}) (*partition, error) {
+func openPartition(smallPartsPath, bigPartsPath string, getDeletedMetricIDs func() *uint64set.Set) (*partition, error) {
 	smallPartsPath = filepath.Clean(smallPartsPath)
 	bigPartsPath = filepath.Clean(bigPartsPath)
 
@@ -255,7 +262,7 @@ func openPartition(smallPartsPath, bigPartsPath string, getDeletedMetricIDs func
 	return pt, nil
 }
 
-func newPartition(name, smallPartsPath, bigPartsPath string, getDeletedMetricIDs func() map[uint64]struct{}) *partition {
+func newPartition(name, smallPartsPath, bigPartsPath string, getDeletedMetricIDs func() *uint64set.Set) *partition {
 	return &partition{
 		name:           name,
 		smallPartsPath: smallPartsPath,
@@ -727,7 +734,7 @@ func (pt *partition) mergePartsOptimal(pws []*partWrapper) error {
 	return nil
 }
 
-var mergeWorkers = func() int {
+var mergeWorkersCount = func() int {
 	n := runtime.GOMAXPROCS(-1) / 2
 	if n <= 0 {
 		n = 1
@@ -735,16 +742,47 @@ var mergeWorkers = func() int {
 	return n
 }()
 
+var (
+	bigMergeWorkersCount   = uint64(mergeWorkersCount)
+	smallMergeWorkersCount = uint64(mergeWorkersCount)
+)
+
+var (
+	bigMergeConcurrencyLimitCh   = make(chan struct{}, bigMergeWorkersCount)
+	smallMergeConcurrencyLimitCh = make(chan struct{}, smallMergeWorkersCount)
+)
+
+// SetBigMergeWorkersCount sets the maximum number of concurrent mergers for big blocks.
+//
+// The function must be called before opening or creating any storage.
+func SetBigMergeWorkersCount(n int) {
+	if n <= 0 {
+		// Do nothing
+		return
+	}
+	atomic.StoreUint64(&bigMergeWorkersCount, uint64(n))
+}
+
+// SetSmallMergeWorkersCount sets the maximum number of concurrent mergers for small blocks.
+//
+// The function must be called before opening or creating any storage.
+func SetSmallMergeWorkersCount(n int) {
+	if n <= 0 {
+		// Do nothing
+		return
+	}
+	atomic.StoreUint64(&smallMergeWorkersCount, uint64(n))
+}
+
 func (pt *partition) startMergeWorkers() {
-	for i := 0; i < mergeWorkers; i++ {
+	for i := 0; i < mergeWorkersCount; i++ {
 		pt.smallPartsMergerWG.Add(1)
 		go func() {
 			pt.smallPartsMerger()
 			pt.smallPartsMergerWG.Done()
 		}()
 	}
-
-	for i := 0; i < mergeWorkers; i++ {
+	for i := 0; i < mergeWorkersCount; i++ {
 		pt.bigPartsMergerWG.Add(1)
 		go func() {
 			pt.bigPartsMerger()
@@ -791,7 +829,7 @@ func (pt *partition) partsMerger(mergerFunc func(isFinal bool) error) error {
 		if err != errNothingToMerge {
 			return err
 		}
-		if time.Since(lastMergeTime) > 10*time.Second {
+		if time.Since(lastMergeTime) > 30*time.Second {
 			// We have free time for merging into bigger parts.
 			// This should improve select performance.
 			lastMergeTime = time.Now()
@@ -818,11 +856,11 @@ func maxRowsByPath(path string) uint64 {
 
 	// Calculate the maximum number of rows in the output merge part
 	// by dividing the freeSpace by the number of concurrent
-	// mergeWorkers for big parts.
+	// mergeWorkersCount for big parts.
 	// This assumes each row is compressed into 1 byte. Production
 	// simulation shows that each row usually occupies up to 0.5 bytes,
 	// so this is quite safe assumption.
-	maxRows := freeSpace / uint64(mergeWorkers)
+	maxRows := freeSpace / uint64(mergeWorkersCount)
 	if maxRows > maxRowsPerBigPart {
 		maxRows = maxRowsPerBigPart
 	}
@@ -859,6 +897,11 @@ type freeSpaceEntry struct {
 }
 
 func (pt *partition) mergeBigParts(isFinal bool) error {
+	bigMergeConcurrencyLimitCh <- struct{}{}
+	defer func() {
+		<-bigMergeConcurrencyLimitCh
+	}()
+
 	maxRows := maxRowsByPath(pt.bigPartsPath)
 
 	pt.partsLock.Lock()
@@ -878,10 +921,15 @@ func (pt *partition) mergeBigParts(isFinal bool) error {
 }
 
 func (pt *partition) mergeSmallParts(isFinal bool) error {
+	smallMergeConcurrencyLimitCh <- struct{}{}
+	defer func() {
+		<-smallMergeConcurrencyLimitCh
+	}()
+
 	maxRows := maxRowsByPath(pt.smallPartsPath)
 	if maxRows > maxRowsPerSmallPart() {
 		// The output part may go to big part,
-		// so make sure it as enough space.
+		// so make sure it has enough space.
 		maxBigPartRows := maxRowsByPath(pt.bigPartsPath)
 		if maxRows > maxBigPartRows {
 			maxRows = maxBigPartRows
@@ -1158,13 +1206,10 @@ func appendPartsToMerge(dst, src []*partWrapper, maxPartsToMerge int, maxRows ui
 	sort.Slice(src, func(i, j int) bool {
 		a := &src[i].p.ph
 		b := &src[j].p.ph
-		if a.RowsCount < b.RowsCount {
-			return true
+		if a.RowsCount == b.RowsCount {
+			return a.MinTimestamp > b.MinTimestamp
 		}
-		if a.RowsCount > b.RowsCount {
-			return false
-		}
-		return a.MinTimestamp > b.MinTimestamp
+		return a.RowsCount < b.RowsCount
 	})
 
 	n := maxPartsToMerge
@@ -1178,36 +1223,40 @@ func appendPartsToMerge(dst, src []*partWrapper, maxPartsToMerge int, maxRows ui
 	maxM := float64(0)
 	for i := 2; i <= n; i++ {
 		for j := 0; j <= len(src)-i; j++ {
+			a := src[j : j+i]
 			rowsSum := uint64(0)
-			for _, pw := range src[j : j+i] {
+			for _, pw := range a {
 				rowsSum += pw.p.ph.RowsCount
 			}
 			if rowsSum > maxRows {
-				continue
+				// There is no need in verifying remaining parts with higher number of rows
+				break
 			}
-			m := float64(rowsSum) / float64(src[j+i-1].p.ph.RowsCount)
+			m := float64(rowsSum) / float64(a[len(a)-1].p.ph.RowsCount)
 			if m < maxM {
 				continue
 			}
 			maxM = m
-			pws = src[j : j+i]
+			pws = a
 		}
 	}
 
-	minM := float64(maxPartsToMerge / 2)
-	if minM < 2 {
-		minM = 2
+	minM := float64(maxPartsToMerge) / 2
+	if minM < 1.7 {
+		minM = 1.7
 	}
 	if maxM < minM {
 		// There is no sense in merging parts with too small m.
 		return dst
 	}
-
 	return append(dst, pws...)
 }
 
 func openParts(pathPrefix1, pathPrefix2, path string) ([]*partWrapper, error) {
-	// Verify that the directory for the parts exists.
+	// The path can be missing after restoring from backup, so create it if needed.
+	if err := fs.MkdirAllIfNotExist(path); err != nil {
+		return nil, err
+	}
 	d, err := os.Open(path)
 	if err != nil {
 		return nil, fmt.Errorf("cannot open directory %q: %s", path, err)

lib/storage/partition_search.go

@@ -55,7 +55,10 @@ func (pts *partitionSearch) reset() {
 
 // Init initializes the search in the given partition for the given tsid and tr.
 //
-// MustClose must be called when partition search is done.
+// tsids must be sorted.
+// tsids cannot be modified after the Init call, since it is owned by pts.
+//
+/// MustClose must be called when partition search is done.
 func (pts *partitionSearch) Init(pt *partition, tsids []TSID, tr TimeRange, fetchData bool) {
 	if pts.needClosing {
 		logger.Panicf("BUG: missing partitionSearch.MustClose call before the next call to Init")

lib/storage/partition_search_test.go

@@ -7,6 +7,8 @@ import (
 	"sort"
 	"testing"
 	"time"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/uint64set"
 )
 
 func TestPartitionSearch(t *testing.T) {
@@ -284,6 +286,6 @@ func testPartitionSearchSerial(pt *partition, tsids []TSID, tr TimeRange, rbsExp
 	return nil
 }
 
-func nilGetDeletedMetricIDs() map[uint64]struct{} {
+func nilGetDeletedMetricIDs() *uint64set.Set {
 	return nil
 }

lib/storage/partition_test.go

@@ -14,34 +14,34 @@ func TestPartitionMaxRowsByPath(t *testing.T) {
 }
 
 func TestAppendPartsToMerge(t *testing.T) {
-	testAppendPartsToMerge(t, 2, []int{}, nil)
-	testAppendPartsToMerge(t, 2, []int{123}, nil)
-	testAppendPartsToMerge(t, 2, []int{4, 2}, nil)
-	testAppendPartsToMerge(t, 2, []int{128, 64, 32, 16, 8, 4, 2, 1}, nil)
-	testAppendPartsToMerge(t, 4, []int{128, 64, 32, 10, 9, 7, 2, 1}, []int{2, 7, 9, 10})
-	testAppendPartsToMerge(t, 2, []int{128, 64, 32, 16, 8, 4, 2, 2}, []int{2, 2})
-	testAppendPartsToMerge(t, 4, []int{128, 64, 32, 16, 8, 4, 2, 2}, []int{2, 2, 4, 8})
-	testAppendPartsToMerge(t, 2, []int{1, 1}, []int{1, 1})
-	testAppendPartsToMerge(t, 2, []int{2, 2, 2}, []int{2, 2})
-	testAppendPartsToMerge(t, 2, []int{4, 2, 4}, []int{4, 4})
-	testAppendPartsToMerge(t, 2, []int{1, 3, 7, 2}, nil)
-	testAppendPartsToMerge(t, 3, []int{1, 3, 7, 2}, []int{1, 2, 3})
-	testAppendPartsToMerge(t, 4, []int{1, 3, 7, 2}, []int{1, 2, 3})
-	testAppendPartsToMerge(t, 3, []int{11, 1, 10, 100, 10}, []int{10, 10, 11})
+	testAppendPartsToMerge(t, 2, []uint64{}, nil)
+	testAppendPartsToMerge(t, 2, []uint64{123}, nil)
+	testAppendPartsToMerge(t, 2, []uint64{4, 2}, nil)
+	testAppendPartsToMerge(t, 2, []uint64{128, 64, 32, 16, 8, 4, 2, 1}, nil)
+	testAppendPartsToMerge(t, 4, []uint64{128, 64, 32, 10, 9, 7, 2, 1}, []uint64{2, 7, 9, 10})
+	testAppendPartsToMerge(t, 2, []uint64{128, 64, 32, 16, 8, 4, 2, 2}, []uint64{2, 2})
+	testAppendPartsToMerge(t, 4, []uint64{128, 64, 32, 16, 8, 4, 2, 2}, []uint64{2, 2, 4, 8})
+	testAppendPartsToMerge(t, 2, []uint64{1, 1}, []uint64{1, 1})
+	testAppendPartsToMerge(t, 2, []uint64{2, 2, 2}, []uint64{2, 2})
+	testAppendPartsToMerge(t, 2, []uint64{4, 2, 4}, []uint64{4, 4})
+	testAppendPartsToMerge(t, 2, []uint64{1, 3, 7, 2}, nil)
+	testAppendPartsToMerge(t, 3, []uint64{1, 3, 7, 2}, []uint64{1, 2, 3})
+	testAppendPartsToMerge(t, 4, []uint64{1, 3, 7, 2}, []uint64{1, 2, 3})
+	testAppendPartsToMerge(t, 3, []uint64{11, 1, 10, 100, 10}, []uint64{10, 10, 11})
 }
 
 func TestAppendPartsToMergeManyParts(t *testing.T) {
 	// Verify that big number of parts are merged into minimal number of parts
 	// using minimum merges.
-	var a []int
+	var a []uint64
 	maxOutPartRows := uint64(0)
 	for i := 0; i < 1024; i++ {
-		n := int(rand.NormFloat64() * 1e9)
+		n := uint64(uint32(rand.NormFloat64() * 1e9))
 		if n < 0 {
 			n = -n
 		}
 		n++
-		maxOutPartRows += uint64(n)
+		maxOutPartRows += n
 		a = append(a, n)
 	}
 	pws := newTestPartWrappersForRowsCount(a)
@@ -67,11 +67,10 @@ func TestAppendPartsToMergeManyParts(t *testing.T) {
 			}
 		}
 		pw := &partWrapper{
-			p: &part{
-				ph: partHeader{
-					RowsCount: rowsCount,
-				},
-			},
+			p: &part{},
+		}
+		pw.p.ph = partHeader{
+			RowsCount: rowsCount,
 		}
 		rowsMerged += rowsCount
 		pwsNew = append(pwsNew, pw)
@@ -94,7 +93,7 @@ func TestAppendPartsToMergeManyParts(t *testing.T) {
 	}
 }
 
-func testAppendPartsToMerge(t *testing.T, maxPartsToMerge int, initialRowsCount, expectedRowsCount []int) {
+func testAppendPartsToMerge(t *testing.T, maxPartsToMerge int, initialRowsCount, expectedRowsCount []uint64) {
 	t.Helper()
 
 	pws := newTestPartWrappersForRowsCount(initialRowsCount)
@@ -111,8 +110,10 @@ func testAppendPartsToMerge(t *testing.T, maxPartsToMerge int, initialRowsCount,
 	prefix := []*partWrapper{
 		{
 			p: &part{
-				ph: partHeader{
-					RowsCount: 1234,
+				partInternals: partInternals{
+					ph: partHeader{
+						RowsCount: 1234,
+					},
 				},
 			},
 		},
@@ -132,21 +133,23 @@ func testAppendPartsToMerge(t *testing.T, maxPartsToMerge int, initialRowsCount,
 	}
 }
 
-func newTestRowsCountFromPartWrappers(pws []*partWrapper) []int {
-	var rowsCount []int
+func newTestRowsCountFromPartWrappers(pws []*partWrapper) []uint64 {
+	var rowsCount []uint64
 	for _, pw := range pws {
-		rowsCount = append(rowsCount, int(pw.p.ph.RowsCount))
+		rowsCount = append(rowsCount, pw.p.ph.RowsCount)
 	}
 	return rowsCount
 }
 
-func newTestPartWrappersForRowsCount(rowsCount []int) []*partWrapper {
+func newTestPartWrappersForRowsCount(rowsCount []uint64) []*partWrapper {
 	var pws []*partWrapper
 	for _, rc := range rowsCount {
 		pw := &partWrapper{
 			p: &part{
-				ph: partHeader{
-					RowsCount: uint64(rc),
+				partInternals: partInternals{
+					ph: partHeader{
+						RowsCount: rc,
+					},
 				},
 			},
 		}

lib/storage/raw_row.go

@@ -48,42 +48,30 @@ type rawRowsSort []rawRow
 func (rrs *rawRowsSort) Len() int { return len(*rrs) }
 func (rrs *rawRowsSort) Less(i, j int) bool {
 	x := *rrs
+	if i < 0 || j < 0 || i >= len(x) || j >= len(x) {
+		// This is no-op for compiler, so it doesn't generate panic code
+		// for out of range access on x[i], x[j] below
+		return false
+	}
 	a := &x[i]
 	b := &x[j]
 	ta := &a.TSID
 	tb := &b.TSID
-	if ta.MetricID == tb.MetricID {
-		// Fast path - identical TSID values.
-		return a.Timestamp < b.Timestamp
-	}
 
-	// Slow path - compare TSIDs.
 	// Manually inline TSID.Less here, since the compiler doesn't inline it yet :(
-	if ta.MetricGroupID < tb.MetricGroupID {
-		return true
+	if ta.MetricGroupID != tb.MetricGroupID {
+		return ta.MetricGroupID < tb.MetricGroupID
 	}
-	if ta.MetricGroupID > tb.MetricGroupID {
-		return false
+	if ta.JobID != tb.JobID {
+		return ta.JobID < tb.JobID
 	}
-	if ta.JobID < tb.JobID {
-		return true
+	if ta.InstanceID != tb.InstanceID {
+		return ta.InstanceID < tb.InstanceID
 	}
-	if ta.JobID > tb.JobID {
-		return false
+	if ta.MetricID != tb.MetricID {
+		return ta.MetricID < tb.MetricID
 	}
-	if ta.InstanceID < tb.InstanceID {
-		return true
-	}
-	if ta.InstanceID > tb.InstanceID {
-		return false
-	}
-	if ta.MetricID < tb.MetricID {
-		return true
-	}
-	if ta.MetricID > tb.MetricID {
-		return false
-	}
-	return false
+	return a.Timestamp < b.Timestamp
 }
 func (rrs *rawRowsSort) Swap(i, j int) {
 	x := *rrs

lib/storage/storage.go

@@ -20,6 +20,7 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/memory"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/timerpool"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/uint64set"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/workingsetcache"
 	"github.com/VictoriaMetrics/fastcache"
 )
@@ -28,6 +29,15 @@ const maxRetentionMonths = 12 * 100
 
 // Storage represents TSDB storage.
 type Storage struct {
+	// Atomic counters must go at the top of the structure in order to properly align by 8 bytes on 32-bit archs.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212 .
+	tooSmallTimestampRows uint64
+	tooBigTimestampRows   uint64
+
+	addRowsConcurrencyLimitReached uint64
+	addRowsConcurrencyLimitTimeout uint64
+	addRowsConcurrencyDroppedRows  uint64
+
 	path            string
 	cachePath       string
 	retentionMonths int
@@ -59,19 +69,12 @@ type Storage struct {
 
 	// Pending MetricID values to be added to currHourMetricIDs.
 	pendingHourMetricIDsLock sync.Mutex
-	pendingHourMetricIDs     map[uint64]struct{}
+	pendingHourMetricIDs     *uint64set.Set
 
 	stop chan struct{}
 
 	currHourMetricIDsUpdaterWG sync.WaitGroup
 	retentionWatcherWG         sync.WaitGroup
-
-	tooSmallTimestampRows uint64
-	tooBigTimestampRows   uint64
-
-	addRowsConcurrencyLimitReached uint64
-	addRowsConcurrencyLimitTimeout uint64
-	addRowsConcurrencyDroppedRows  uint64
 }
 
 // OpenStorage opens storage on the given path with the given number of retention months.
@@ -122,7 +125,7 @@ func OpenStorage(path string, retentionMonths int) (*Storage, error) {
 	hmPrev := s.mustLoadHourMetricIDs(hour-1, "prev_hour_metric_ids")
 	s.currHourMetricIDs.Store(hmCurr)
 	s.prevHourMetricIDs.Store(hmPrev)
-	s.pendingHourMetricIDs = make(map[uint64]struct{})
+	s.pendingHourMetricIDs = &uint64set.Set{}
 
 	// Load indexdb
 	idbPath := path + "/indexdb"
@@ -158,7 +161,7 @@ func (s *Storage) debugFlush() {
 	s.idb().tb.DebugFlush()
 }
 
-func (s *Storage) getDeletedMetricIDs() map[uint64]struct{} {
+func (s *Storage) getDeletedMetricIDs() *uint64set.Set {
 	return s.idb().getDeletedMetricIDs()
 }
 
@@ -364,9 +367,9 @@ func (s *Storage) UpdateMetrics(m *Metrics) {
 
 	hmCurr := s.currHourMetricIDs.Load().(*hourMetricIDs)
 	hmPrev := s.prevHourMetricIDs.Load().(*hourMetricIDs)
-	hourMetricIDsLen := len(hmPrev.m)
-	if len(hmCurr.m) > hourMetricIDsLen {
-		hourMetricIDsLen = len(hmCurr.m)
+	hourMetricIDsLen := hmPrev.m.Len()
+	if hmCurr.m.Len() > hourMetricIDsLen {
+		hourMetricIDsLen = hmCurr.m.Len()
 	}
 	m.HourMetricIDCacheSize += uint64(hourMetricIDsLen)
 
@@ -508,11 +511,11 @@ func (s *Storage) mustLoadHourMetricIDs(hour uint64, name string) *hourMetricIDs
 		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)
+	m := &uint64set.Set{}
 	for i := uint64(0); i < hmLen; i++ {
 		metricID := encoding.UnmarshalUint64(src)
 		src = src[8:]
-		m[metricID] = struct{}{}
+		m.Add(metricID)
 	}
 	logger.Infof("loaded %s from %q in %s; entriesCount: %d; sizeBytes: %d", name, path, time.Since(startTime), hmLen, srcOrigLen)
 	return &hourMetricIDs{
@@ -526,21 +529,21 @@ 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)
+	dst := make([]byte, 0, hm.m.Len()*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, uint64(hm.m.Len()))
+	for _, metricID := range hm.m.AppendTo(nil) {
 		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))
+	logger.Infof("saved %s to %q in %s; entriesCount: %d; sizeBytes: %d", name, path, time.Since(startTime), hm.m.Len(), len(dst))
 }
 
 func (s *Storage) mustLoadCache(info, name string, sizeBytes int) *workingsetcache.Cache {
@@ -579,7 +582,7 @@ func nextRetentionDuration(retentionMonths int) time.Duration {
 	return deadline.Sub(t)
 }
 
-// searchTSIDs returns TSIDs for the given tfss and the given tr.
+// searchTSIDs returns sorted TSIDs for the given tfss and the given tr.
 func (s *Storage) searchTSIDs(tfss []*TagFilters, tr TimeRange, maxMetrics int) ([]TSID, error) {
 	// Do not cache tfss -> tsids here, since the caching is performed
 	// on idb level.
@@ -770,7 +773,7 @@ var (
 
 func (s *Storage) add(rows []rawRow, mrs []MetricRow, precisionBits uint8) ([]rawRow, error) {
 	// Return only the last error, since it has no sense in returning all errors.
-	var lastError error
+	var lastWarn error
 
 	var is *indexSearch
 	var mn *MetricName
@@ -794,13 +797,13 @@ func (s *Storage) add(rows []rawRow, mrs []MetricRow, precisionBits uint8) ([]ra
 		}
 		if mr.Timestamp < minTimestamp {
 			// Skip rows with too small timestamps outside the retention.
-			lastError = fmt.Errorf("cannot insert row with too small timestamp %d outside the retention; minimum allowed timestamp is %d", mr.Timestamp, minTimestamp)
+			lastWarn = fmt.Errorf("cannot insert row with too small timestamp %d outside the retention; minimum allowed timestamp is %d", mr.Timestamp, minTimestamp)
 			atomic.AddUint64(&s.tooSmallTimestampRows, 1)
 			continue
 		}
 		if mr.Timestamp > maxTimestamp {
 			// Skip rows with too big timestamps significantly exceeding the current time.
-			lastError = fmt.Errorf("cannot insert row with too big timestamp %d exceeding the current time; maximum allowd timestamp is %d", mr.Timestamp, maxTimestamp)
+			lastWarn = fmt.Errorf("cannot insert row with too big timestamp %d exceeding the current time; maximum allowd timestamp is %d", mr.Timestamp, maxTimestamp)
 			atomic.AddUint64(&s.tooBigTimestampRows, 1)
 			continue
 		}
@@ -810,11 +813,7 @@ func (s *Storage) add(rows []rawRow, mrs []MetricRow, precisionBits uint8) ([]ra
 		r.Value = mr.Value
 		r.PrecisionBits = precisionBits
 		if s.getTSIDFromCache(&r.TSID, mr.MetricNameRaw) {
-			if len(dmis) == 0 {
-				// Fast path - the TSID for the given MetricName has been found in cache and isn't deleted.
-				continue
-			}
-			if _, deleted := dmis[r.TSID.MetricID]; !deleted {
+			if !dmis.Has(r.TSID.MetricID) {
 				// Fast path - the TSID for the given MetricName has been found in cache and isn't deleted.
 				continue
 			}
@@ -830,7 +829,7 @@ func (s *Storage) add(rows []rawRow, mrs []MetricRow, precisionBits uint8) ([]ra
 			// Do not stop adding rows on error - just skip invalid row.
 			// This guarantees that invalid rows don't prevent
 			// from adding valid rows into the storage.
-			lastError = fmt.Errorf("cannot unmarshal MetricNameRaw %q: %s", mr.MetricNameRaw, err)
+			lastWarn = fmt.Errorf("cannot unmarshal MetricNameRaw %q: %s", mr.MetricNameRaw, err)
 			j--
 			continue
 		}
@@ -840,12 +839,15 @@ func (s *Storage) add(rows []rawRow, mrs []MetricRow, precisionBits uint8) ([]ra
 			// Do not stop adding rows on error - just skip invalid row.
 			// This guarantees that invalid rows don't prevent
 			// from adding valid rows into the storage.
-			lastError = fmt.Errorf("cannot obtain TSID for MetricName %q: %s", kb.B, err)
+			lastWarn = fmt.Errorf("cannot obtain TSID for MetricName %q: %s", kb.B, err)
 			j--
 			continue
 		}
 		s.putTSIDToCache(&r.TSID, mr.MetricNameRaw)
 	}
+	if lastWarn != nil {
+		logger.Errorf("warn occurred during rows addition: %s", lastWarn)
+	}
 	if is != nil {
 		kbPool.Put(kb)
 		PutMetricName(mn)
@@ -853,12 +855,15 @@ func (s *Storage) add(rows []rawRow, mrs []MetricRow, precisionBits uint8) ([]ra
 	}
 	rows = rows[:rowsLen+j]
 
+	var lastError error
 	if err := s.tb.AddRows(rows); err != nil {
 		lastError = fmt.Errorf("cannot add rows to table: %s", err)
 	}
-	lastError = s.updateDateMetricIDCache(rows, lastError)
+	if err := s.updateDateMetricIDCache(rows, lastError); err != nil {
+		lastError = err
+	}
 	if lastError != nil {
-		return rows, fmt.Errorf("errors occurred during rows addition: %s", lastError)
+		return rows, fmt.Errorf("error occurred during rows addition: %s", lastError)
 	}
 	return rows, nil
 }
@@ -884,12 +889,12 @@ func (s *Storage) updateDateMetricIDCache(rows []rawRow, lastError error) error
 		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 {
+			if hm.m.Has(metricID) {
 				// Fast path: the metricID is in the current hour cache.
 				continue
 			}
 			s.pendingHourMetricIDsLock.Lock()
-			s.pendingHourMetricIDs[metricID] = struct{}{}
+			s.pendingHourMetricIDs.Add(metricID)
 			s.pendingHourMetricIDsLock.Unlock()
 		}
 
@@ -915,7 +920,7 @@ func (s *Storage) updateDateMetricIDCache(rows []rawRow, lastError error) error
 func (s *Storage) updateCurrHourMetricIDs() {
 	hm := s.currHourMetricIDs.Load().(*hourMetricIDs)
 	s.pendingHourMetricIDsLock.Lock()
-	newMetricIDsLen := len(s.pendingHourMetricIDs)
+	newMetricIDsLen := s.pendingHourMetricIDs.Len()
 	s.pendingHourMetricIDsLock.Unlock()
 	hour := uint64(timestampFromTime(time.Now())) / msecPerHour
 	if newMetricIDsLen == 0 && hm.hour == hour {
@@ -924,24 +929,19 @@ func (s *Storage) updateCurrHourMetricIDs() {
 	}
 
 	// Slow path: hm.m must be updated with non-empty s.pendingHourMetricIDs.
-	var m map[uint64]struct{}
+	var m *uint64set.Set
 	isFull := hm.isFull
 	if hm.hour == hour {
-		m = make(map[uint64]struct{}, len(hm.m)+newMetricIDsLen)
-		for metricID := range hm.m {
-			m[metricID] = struct{}{}
-		}
+		m = hm.m.Clone()
 	} else {
-		m = make(map[uint64]struct{}, newMetricIDsLen)
+		m = &uint64set.Set{}
 		isFull = true
 	}
 	s.pendingHourMetricIDsLock.Lock()
 	newMetricIDs := s.pendingHourMetricIDs
-	s.pendingHourMetricIDs = make(map[uint64]struct{}, len(newMetricIDs))
+	s.pendingHourMetricIDs = &uint64set.Set{}
 	s.pendingHourMetricIDsLock.Unlock()
-	for metricID := range newMetricIDs {
-		m[metricID] = struct{}{}
-	}
+	m.Union(newMetricIDs)
 
 	hmNew := &hourMetricIDs{
 		m:      m,
@@ -955,7 +955,7 @@ func (s *Storage) updateCurrHourMetricIDs() {
 }
 
 type hourMetricIDs struct {
-	m      map[uint64]struct{}
+	m      *uint64set.Set
 	hour   uint64
 	isFull bool
 }

lib/storage/storage_test.go

@@ -9,6 +9,8 @@ import (
 	"testing"
 	"testing/quick"
 	"time"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/uint64set"
 )
 
 func TestUpdateCurrHourMetricIDs(t *testing.T) {
@@ -16,19 +18,18 @@ func TestUpdateCurrHourMetricIDs(t *testing.T) {
 		var s Storage
 		s.currHourMetricIDs.Store(&hourMetricIDs{})
 		s.prevHourMetricIDs.Store(&hourMetricIDs{})
-		s.pendingHourMetricIDs = make(map[uint64]struct{})
+		s.pendingHourMetricIDs = &uint64set.Set{}
 		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: {},
-			},
+			m:    &uint64set.Set{},
 			hour: 123,
 		}
+		hmOrig.m.Add(12)
+		hmOrig.m.Add(34)
 		s.currHourMetricIDs.Store(hmOrig)
 		s.updateCurrHourMetricIDs()
 		hmCurr := s.currHourMetricIDs.Load().(*hourMetricIDs)
@@ -39,8 +40,8 @@ func TestUpdateCurrHourMetricIDs(t *testing.T) {
 				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.m.Len() != 0 {
+			t.Fatalf("unexpected length of hm.m; got %d; want %d", hmCurr.m.Len(), 0)
 		}
 		if !hmCurr.isFull {
 			t.Fatalf("unexpected hmCurr.isFull; got %v; want %v", hmCurr.isFull, true)
@@ -51,20 +52,19 @@ func TestUpdateCurrHourMetricIDs(t *testing.T) {
 			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)
+		if s.pendingHourMetricIDs.Len() != 0 {
+			t.Fatalf("unexpected s.pendingHourMetricIDs.Len(); got %d; want %d", s.pendingHourMetricIDs.Len(), 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: {},
-			},
+			m:    &uint64set.Set{},
 			hour: hour,
 		}
+		hmOrig.m.Add(12)
+		hmOrig.m.Add(34)
 		s.currHourMetricIDs.Store(hmOrig)
 		s.updateCurrHourMetricIDs()
 		hmCurr := s.currHourMetricIDs.Load().(*hourMetricIDs)
@@ -90,27 +90,25 @@ func TestUpdateCurrHourMetricIDs(t *testing.T) {
 			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)
+		if s.pendingHourMetricIDs.Len() != 0 {
+			t.Fatalf("unexpected s.pendingHourMetricIDs.Len(); got %d; want %d", s.pendingHourMetricIDs.Len(), 0)
 		}
 	})
 	t.Run("nonempty_pending_metric_ids_stale_curr_hour", func(t *testing.T) {
 		s := newStorage()
-		pendingHourMetricIDs := map[uint64]struct{}{
-			343:     {},
-			32424:   {},
-			8293432: {},
-		}
+		pendingHourMetricIDs := &uint64set.Set{}
+		pendingHourMetricIDs.Add(343)
+		pendingHourMetricIDs.Add(32424)
+		pendingHourMetricIDs.Add(8293432)
 		s.pendingHourMetricIDs = pendingHourMetricIDs
 
 		hour := uint64(timestampFromTime(time.Now())) / msecPerHour
 		hmOrig := &hourMetricIDs{
-			m: map[uint64]struct{}{
-				12: {},
-				34: {},
-			},
+			m:    &uint64set.Set{},
 			hour: 123,
 		}
+		hmOrig.m.Add(12)
+		hmOrig.m.Add(34)
 		s.currHourMetricIDs.Store(hmOrig)
 		s.updateCurrHourMetricIDs()
 		hmCurr := s.currHourMetricIDs.Load().(*hourMetricIDs)
@@ -133,27 +131,25 @@ func TestUpdateCurrHourMetricIDs(t *testing.T) {
 			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)
+		if s.pendingHourMetricIDs.Len() != 0 {
+			t.Fatalf("unexpected s.pendingHourMetricIDs.Len(); got %d; want %d", s.pendingHourMetricIDs.Len(), 0)
 		}
 	})
 	t.Run("nonempty_pending_metric_ids_valid_curr_hour", func(t *testing.T) {
 		s := newStorage()
-		pendingHourMetricIDs := map[uint64]struct{}{
-			343:     {},
-			32424:   {},
-			8293432: {},
-		}
+		pendingHourMetricIDs := &uint64set.Set{}
+		pendingHourMetricIDs.Add(343)
+		pendingHourMetricIDs.Add(32424)
+		pendingHourMetricIDs.Add(8293432)
 		s.pendingHourMetricIDs = pendingHourMetricIDs
 
 		hour := uint64(timestampFromTime(time.Now())) / msecPerHour
 		hmOrig := &hourMetricIDs{
-			m: map[uint64]struct{}{
-				12: {},
-				34: {},
-			},
+			m:    &uint64set.Set{},
 			hour: hour,
 		}
+		hmOrig.m.Add(12)
+		hmOrig.m.Add(34)
 		s.currHourMetricIDs.Store(hmOrig)
 		s.updateCurrHourMetricIDs()
 		hmCurr := s.currHourMetricIDs.Load().(*hourMetricIDs)
@@ -166,9 +162,10 @@ func TestUpdateCurrHourMetricIDs(t *testing.T) {
 			// Do not run other checks, since they may fail.
 			return
 		}
-		m := getMetricIDsCopy(pendingHourMetricIDs)
-		for metricID := range hmOrig.m {
-			m[metricID] = struct{}{}
+		m := pendingHourMetricIDs.Clone()
+		origMetricIDs := hmOrig.m.AppendTo(nil)
+		for _, metricID := range origMetricIDs {
+			m.Add(metricID)
 		}
 		if !reflect.DeepEqual(hmCurr.m, m) {
 			t.Fatalf("unexpected hm.m; got %v; want %v", hmCurr.m, m)
@@ -183,8 +180,8 @@ func TestUpdateCurrHourMetricIDs(t *testing.T) {
 			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)
+		if s.pendingHourMetricIDs.Len() != 0 {
+			t.Fatalf("unexpected s.pendingHourMetricIDs.Len(); got %d; want %d", s.pendingHourMetricIDs.Len(), 0)
 		}
 	})
 }

lib/storage/table.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fs"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/uint64set"
 )
 
 // table represents a single table with time series data.
@@ -18,7 +19,7 @@ type table struct {
 	smallPartitionsPath string
 	bigPartitionsPath   string
 
-	getDeletedMetricIDs func() map[uint64]struct{}
+	getDeletedMetricIDs func() *uint64set.Set
 
 	ptws     []*partitionWrapper
 	ptwsLock sync.Mutex
@@ -33,11 +34,15 @@ type table struct {
 
 // partitionWrapper provides refcounting mechanism for the partition.
 type partitionWrapper struct {
-	pt       *partition
+	// Atomic counters must be at the top of struct for proper 8-byte alignment on 32-bit archs.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/212
+
 	refCount uint64
 
 	// The partition must be dropped if mustDrop > 0
 	mustDrop uint64
+
+	pt *partition
 }
 
 func (ptw *partitionWrapper) incRef() {
@@ -75,7 +80,7 @@ func (ptw *partitionWrapper) scheduleToDrop() {
 // The table is created if it doesn't exist.
 //
 // Data older than the retentionMonths may be dropped at any time.
-func openTable(path string, retentionMonths int, getDeletedMetricIDs func() map[uint64]struct{}) (*table, error) {
+func openTable(path string, retentionMonths int, getDeletedMetricIDs func() *uint64set.Set) (*table, error) {
 	path = filepath.Clean(path)
 
 	// Create a directory for the table if it doesn't exist yet.
@@ -430,7 +435,7 @@ func (tb *table) PutPartitions(ptws []*partitionWrapper) {
 	}
 }
 
-func openPartitions(smallPartitionsPath, bigPartitionsPath string, getDeletedMetricIDs func() map[uint64]struct{}) ([]*partition, error) {
+func openPartitions(smallPartitionsPath, bigPartitionsPath string, getDeletedMetricIDs func() *uint64set.Set) ([]*partition, error) {
 	smallD, err := os.Open(smallPartitionsPath)
 	if err != nil {
 		return nil, fmt.Errorf("cannot open directory with small partitions %q: %s", smallPartitionsPath, err)

lib/storage/table_search.go

@@ -54,6 +54,9 @@ func (ts *tableSearch) reset() {
 
 // Init initializes the ts.
 //
+// tsids must be sorted.
+// tsids cannot be modified after the Init call, since it is owned by ts.
+//
 // MustClose must be called then the tableSearch is done.
 func (ts *tableSearch) Init(tb *table, tsids []TSID, tr TimeRange, fetchData bool) {
 	if ts.needClosing {

lib/storage/tag_filters.go

@@ -19,14 +19,14 @@ type TagFilters struct {
 	tfs []tagFilter
 
 	// Common prefix for all the tag filters.
-	// Contains encoded nsPrefixTagToMetricID.
+	// Contains encoded nsPrefixTagToMetricIDs.
 	commonPrefix []byte
 }
 
 // NewTagFilters returns new TagFilters.
 func NewTagFilters() *TagFilters {
 	return &TagFilters{
-		commonPrefix: marshalCommonPrefix(nil, nsPrefixTagToMetricID),
+		commonPrefix: marshalCommonPrefix(nil, nsPrefixTagToMetricIDs),
 	}
 }
 
@@ -78,7 +78,7 @@ func (tfs *TagFilters) String() string {
 // Reset resets the tf
 func (tfs *TagFilters) Reset() {
 	tfs.tfs = tfs.tfs[:0]
-	tfs.commonPrefix = marshalCommonPrefix(tfs.commonPrefix[:0], nsPrefixTagToMetricID)
+	tfs.commonPrefix = marshalCommonPrefix(tfs.commonPrefix[:0], nsPrefixTagToMetricIDs)
 }
 
 func (tfs *TagFilters) marshal(dst []byte) []byte {
@@ -95,7 +95,7 @@ type tagFilter struct {
 	isNegative bool
 	isRegexp   bool
 
-	// Prefix always contains {nsPrefixTagToMetricID, key}.
+	// Prefix always contains {nsPrefixTagToMetricIDs, key}.
 	// Additionally it contains:
 	//  - value ending with tagSeparatorChar if !isRegexp.
 	//  - non-regexp prefix if isRegexp.
@@ -317,6 +317,9 @@ func getSingleValueFuncExt(re *syntax.Regexp) func(b []byte) bool {
 	case syntax.OpCapture:
 		return getSingleValueFuncExt(re.Sub[0])
 	case syntax.OpLiteral:
+		if !isLiteral(re) {
+			return nil
+		}
 		s := string(re.Rune)
 		return func(b []byte) bool {
 			return string(b) == s
@@ -399,7 +402,7 @@ func isLiteral(re *syntax.Regexp) bool {
 	if re.Op == syntax.OpCapture {
 		return isLiteral(re.Sub[0])
 	}
-	return re.Op == syntax.OpLiteral
+	return re.Op == syntax.OpLiteral && re.Flags&syntax.FoldCase == 0
 }
 
 func getOrValues(expr string) []string {
@@ -420,6 +423,9 @@ func getOrValuesExt(re *syntax.Regexp) []string {
 	case syntax.OpCapture:
 		return getOrValuesExt(re.Sub[0])
 	case syntax.OpLiteral:
+		if !isLiteral(re) {
+			return nil
+		}
 		return []string{string(re.Rune)}
 	case syntax.OpEmptyMatch:
 		return []string{""}
@@ -592,13 +598,13 @@ func extractRegexpPrefix(b []byte) ([]byte, []byte) {
 	if re == emptyRegexp {
 		return nil, nil
 	}
-	if re.Op == syntax.OpLiteral && re.Flags&syntax.FoldCase == 0 {
+	if isLiteral(re) {
 		return []byte(string(re.Rune)), nil
 	}
 	var prefix []byte
 	if re.Op == syntax.OpConcat {
 		sub0 := re.Sub[0]
-		if sub0.Op == syntax.OpLiteral && sub0.Flags&syntax.FoldCase == 0 {
+		if isLiteral(sub0) {
 			prefix = []byte(string(sub0.Rune))
 			re.Sub = re.Sub[1:]
 			if len(re.Sub) == 0 {

lib/storage/tag_filters_test.go

@@ -53,11 +53,17 @@ func TestGetRegexpFromCache(t *testing.T) {
 	f("((.*)foo(.*))", nil, []string{"foo", "xfoo", "foox", "xfoobar"}, []string{"", "bar", "foxx"})
 	f(".+foo", nil, []string{"afoo", "bbfoo"}, []string{"foo", "foobar", "afoox", ""})
 	f("a|b", []string{"a", "b"}, []string{"a", "b"}, []string{"xa", "bx", "xab", ""})
+	f("(a|b)", []string{"a", "b"}, []string{"a", "b"}, []string{"xa", "bx", "xab", ""})
 	f("foo.+", nil, []string{"foox", "foobar"}, []string{"foo", "afoox", "afoo", ""})
 	f(".*foo.*bar", nil, []string{"foobar", "xfoobar", "xfooxbar", "fooxbar"}, []string{"", "foobarx", "afoobarx", "aaa"})
 	f("foo.*bar", nil, []string{"foobar", "fooxbar"}, []string{"xfoobar", "", "foobarx", "aaa"})
 	f("foo.*bar.*", nil, []string{"foobar", "fooxbar", "foobarx", "fooxbarx"}, []string{"", "afoobarx", "aaa", "afoobar"})
 
+	f("(?i)foo", nil, []string{"foo", "Foo", "FOO"}, []string{"xfoo", "foobar", "xFOObar"})
+	f("(?i).+foo", nil, []string{"xfoo", "aaFoo", "bArFOO"}, []string{"foosdf", "xFOObar"})
+	f("(?i)(foo|bar)", nil, []string{"foo", "Foo", "BAR", "bAR"}, []string{"foobar", "xfoo", "xFOObAR"})
+	f("(?i)foo.*bar", nil, []string{"foobar", "FooBAR", "FOOxxbaR"}, []string{"xfoobar", "foobarx", "xFOObarx"})
+
 	f(".*", nil, []string{"", "a", "foo", "foobar"}, nil)
 	f("foo|.*", nil, []string{"", "a", "foo", "foobar"}, nil)
 	f(".+", nil, []string{"a", "foo"}, []string{""})
@@ -323,6 +329,76 @@ func TestTagFilterMatchSuffix(t *testing.T) {
 		mismatch("bar")
 		match("xhttpbar")
 	})
+	t.Run("regexp-iflag-no-suffix", func(t *testing.T) {
+		value := "(?i)http"
+		isNegative := false
+		isRegexp := true
+		expectedPrefix := tvNoTrailingTagSeparator("")
+		init(value, isNegative, isRegexp, expectedPrefix)
+
+		// Must match case-insenstive http
+		match("http")
+		match("HTTP")
+		match("hTTp")
+
+		mismatch("")
+		mismatch("foobar")
+		mismatch("xhttp")
+		mismatch("xhttp://")
+		mismatch("hTTp://foobar.com")
+	})
+	t.Run("negative-regexp-iflag-no-suffix", func(t *testing.T) {
+		value := "(?i)http"
+		isNegative := true
+		isRegexp := true
+		expectedPrefix := tvNoTrailingTagSeparator("")
+		init(value, isNegative, isRegexp, expectedPrefix)
+
+		// Mustn't match case-insensitive http
+		mismatch("http")
+		mismatch("HTTP")
+		mismatch("hTTp")
+
+		match("")
+		match("foobar")
+		match("xhttp")
+		match("xhttp://")
+		match("hTTp://foobar.com")
+	})
+	t.Run("regexp-iflag-any-suffix", func(t *testing.T) {
+		value := "(?i)http.*"
+		isNegative := false
+		isRegexp := true
+		expectedPrefix := tvNoTrailingTagSeparator("")
+		init(value, isNegative, isRegexp, expectedPrefix)
+
+		// Must match case-insenstive http
+		match("http")
+		match("HTTP")
+		match("hTTp://foobar.com")
+
+		mismatch("")
+		mismatch("foobar")
+		mismatch("xhttp")
+		mismatch("xhttp://")
+	})
+	t.Run("negative-regexp-iflag-any-suffix", func(t *testing.T) {
+		value := "(?i)http.*"
+		isNegative := true
+		isRegexp := true
+		expectedPrefix := tvNoTrailingTagSeparator("")
+		init(value, isNegative, isRegexp, expectedPrefix)
+
+		// Mustn't match case-insensitive http
+		mismatch("http")
+		mismatch("HTTP")
+		mismatch("hTTp://foobar.com")
+
+		match("")
+		match("foobar")
+		match("xhttp")
+		match("xhttp://")
+	})
 	t.Run("non-empty-string-regexp-negative-match", func(t *testing.T) {
 		value := ".+"
 		isNegative := true
@@ -409,6 +485,8 @@ func TestGetOrValues(t *testing.T) {
 	f("foo(?:bar|baz)x(qwe|rt)", []string{"foobarxqwe", "foobarxrt", "foobazxqwe", "foobazxrt"})
 	f("foo(bar||baz)", []string{"foo", "foobar", "foobaz"})
 	f("(a|b|c)(d|e|f)(g|h|k)", nil)
+	f("(?i)foo", nil)
+	f("(?i)(foo|bar)", nil)
 }
 
 func TestGetRegexpPrefix(t *testing.T) {
@@ -463,6 +541,7 @@ func TestGetRegexpPrefix(t *testing.T) {
 	f(t, "a(b|c.*).+", "a", "(?:b|c(?-s:.)*)(?-s:.)+")
 	f(t, "ab|ac", "a", "[b-c]")
 	f(t, "(?i)xyz", "", "(?i:XYZ)")
+	f(t, "(?i)foo|bar", "", "(?i:FOO)|(?i:BAR)")
 	f(t, "(?i)up.+x", "", "(?i:UP)(?-s:.)+(?i:X)")
 	f(t, "(?smi)xy.*z$", "", "(?i:XY)(?s:.)*(?i:Z)(?m:$)")
 

lib/storage/tsid.go

@@ -88,34 +88,16 @@ func (t *TSID) Unmarshal(src []byte) ([]byte, error) {
 
 // Less return true if t < b.
 func (t *TSID) Less(b *TSID) bool {
-	if t.MetricID == b.MetricID {
-		// Fast path - two TSID values are identical.
-		return false
+	// Do not compare MetricIDs here as fast path for determining identical TSIDs,
+	// since identical TSIDs aren't passed here in hot paths.
+	if t.MetricGroupID != b.MetricGroupID {
+		return t.MetricGroupID < b.MetricGroupID
 	}
-
-	if t.MetricGroupID < b.MetricGroupID {
-		return true
+	if t.JobID != b.JobID {
+		return t.JobID < b.JobID
 	}
-	if t.MetricGroupID > b.MetricGroupID {
-		return false
+	if t.InstanceID != b.InstanceID {
+		return t.InstanceID < b.InstanceID
 	}
-	if t.JobID < b.JobID {
-		return true
-	}
-	if t.JobID > b.JobID {
-		return false
-	}
-	if t.InstanceID < b.InstanceID {
-		return true
-	}
-	if t.InstanceID > b.InstanceID {
-		return false
-	}
-	if t.MetricID < b.MetricID {
-		return true
-	}
-	if t.MetricID > b.MetricID {
-		return false
-	}
-	return false
+	return t.MetricID < b.MetricID
 }