Fixes https://github.com/VictoriaMetrics/VictoriaMetrics/issues/10196 Prefer the non StaleNaN value when both StaleNaN and non-StaleNaN samples share the timestamp during deduplication(downsampling). The scenario can occur when: 1. Multiple vmagent instances scrape the same target(without -promscrape.cluster.name flag), one instance fails to scrape due to issues such as network, while others succeed. 2. Multiple vmalert instances evaluate the same recording rule, with one instance receiving a partial response while others receive a complete response. In both cases, since the samples share the same timestamp and represent the metric state at that moment, the non-StaleNaN value is entirely valid, whereas the StaleNaN could be caused by other unknown issues. Therefore, it is reasonable to prioritize the non-StaleNaN value.
App Integration Tests
The apptest package contains the integration tests for the VictoriaMetrics
applications (such as vmstorage, vminsert, and vmselect).
An integration test aims at verifying the behavior of an application as a whole, as apposed to a unit test that verifies the behavior of a building block of an application.
To achieve that an integration test starts an application in a separate process and then issues HTTP requests to it and verifies the responses, examines the metrics the app exposes and/or files it creates, etc.
Note that an object of testing may be not just a single app, but several apps working together. A good example is VictoriaMetrics cluster. An integration test may reproduce an arbitrary cluster configuration and verify how the components work together as a system.
The package provides a collection of helpers to start applications and make queries to them:
app.go- contains the generic code for staring an application and should not be used by integration tests directly.{vmstorage,vminsert,etc}.go- build on top ofapp.goand provide the code for staring a specific application.client.go- provides helper functions for sending HTTP requests to applications.
The integration tests themselves reside in tests/*_test.go files. Apart from having
the _test suffix, there are no strict rules of how to name a file, but the
name should reflect the prevailing purpose of the tests located in that file.
For example, sharding_test.go aims at testing data sharding.
Since integration tests start applications in a separate process, they require
the application binary files to be built and put into the bin directory. The
build rule used for running integration tests, make apptest,
accounts for that, it builds all application binaries before running the tests.
But if you want to run the tests without make, i.e. by executing
go test ./app/apptest, you will need to build the binaries first (for example,
by executing make all).
Not all binaries can be built from master branch, cluster binaries can be built
only from cluster branch. Hence, not all test cases suitable to run in both branches:
- If test is using binaries from
clusterbranch, then test name should be prefixed withTestClusterword - If test is using binaries from
masterbranch, then test name should be prefixed withTestSingleword.