AHeise opened a new pull request #13551:
URL: https://github.com/apache/flink/pull/13551
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## What is the purpose of the change
With the larger refactoring of checkpoint alignment and the additional of
more unaligned checkpoint settings, it becomes increasingly important to
provide a large test coverage.
Unfortunately, adding sufficient test cases in a test matrix appears to be
unrealistic: many of the encountered issues were subtle, sometimes caused by
race conditions or unusual test configurations and often only visible in e2e
tests.
Hence, we like to rely on all existing Flink tests to provide a sufficient
coverage for checkpointing. However, as more and more options in unaligned
checkpoint are going to be implemented in this and the upcoming release,
running all Flink tests - especially e2e - in a test matrix is prohibitively
expensive, even for nightly builds.
Thus, we want to introduce test randomization for all tests that do not use
a specific checkpointing mode. In a similar way, we switched from aligned
checkpoints by default in tests to unaligned checkpoint during the last release
cycle.
To not burden the developers of other components too much, we set the
following requirements:
- Randomization should be seeded in a way that both builds on Azure
pipelines and local builds will result in the same settings to ease debugging
and ensure reproducibility.
- Randomized options should be shown in the test log.
- Execution order of test cases will not influence the randomization.
- Randomization is hidden, no change on any test is needed.
- Randomization only happens during local/remote test execution. User
deployments are not affected.
- Test developers are able to avoid randomization by explicitly
providing checkpoint configs.
## Brief change log
- Add generic method to choose random values for checkpoint config.
- Use it for uninitialized "execution.checkpointing.unaligned".
- Adds flag to enable randomization in root pom. User code will not trigger
randomization but chooses constant default values.
## Verifying this change
- Not covered (yet)
## Does this pull request potentially affect one of the following parts:
- Dependencies (does it add or upgrade a dependency): (yes / **no**)
- The public API, i.e., is any changed class annotated with
`@Public(Evolving)`: (yes / **no**)
- The serializers: (yes / **no** / don't know)
- The runtime per-record code paths (performance sensitive): (yes / **no**
/ don't know)
- Anything that affects deployment or recovery: JobManager (and its
components), Checkpointing, Kubernetes/Yarn/Mesos, ZooKeeper: (yes / **no** /
don't know)
- The S3 file system connector: (yes / **no** / don't know)
## Documentation
- Does this pull request introduce a new feature? (yes / **no**)
- If yes, how is the feature documented? (**not applicable** / docs /
JavaDocs / not documented)
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