[BP-2.3][FLINK-37892][tests] Fix spurious TimeoutException in TestUtils#waitUntil for non-monotonic conditions#28401
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…ntil for non-monotonic conditions (apache#28400) TestUtils#waitUntil evaluated the condition twice: once in the polling loop and again to decide whether to throw. A condition that is momentarily true and then false again (e.g. a live thread count matched with ==) could exit the loop on the first evaluation and then fail the second one, producing a TimeoutException within milliseconds despite a 30s budget. This is the failure mode behind SplitFetcherManagerTest#testCloseBlockingWaitingForFetcherShutdown flaking on CI with sub-second 'timeouts'. Evaluate the condition once per iteration and latch the result, so a condition observed as true always completes the wait. Add a regression test with a condition that is satisfied exactly once. (cherry picked from commit 61723a0)
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What is the purpose of the change
Backport of #28400 to
release-2.3(clean cherry-pick of 61723a0).Fixes the failure mode behind FLINK-37892 (
SplitFetcherManagerTest#testCloseBlockingWaitingForFetcherShutdownflaking on CI).TestUtils#waitUntilevaluates the condition twice — once in the polling loop and again to decide whether to throw. A non-monotonic condition that is momentarily true and then false again can exit the loop on the first evaluation and fail the second, producing aTimeoutExceptionwithin milliseconds despite a 30s budget.SplitFetcherManagerTestpasses exactly such a condition (findThread(THREAD_NAME_PREFIX).size() == 2— a live thread count that can flicker as fetcher threads start/exit).Brief change log
TestUtils#waitUntil(Supplier, Duration, String)to evaluate the condition once per iteration and latch the result: a condition observed as true always completes the wait;TimeoutExceptionis thrown only when the condition was actually false at the deadline.TestUtilsTestwith a regression test whose condition is satisfied exactly once and false afterwards.Verifying this change
This change added tests and can be verified as follows:
TestUtilsTest#testWaitUntilSucceedsForConditionSatisfiedOnlyOncefails against the old implementation with the same spuriousTimeoutException(in ~0.04s) and passes with the fix.SplitFetcherManagerTestpasses against the fixed utility.Does this pull request potentially affect one of the following parts:
@Public(Evolving): noDocumentation
Was generative AI tooling used to co-author this PR?
Yes