[jira] [Commented] (FLINK-29611) Fix flaky tests in CoBroadcastWithNonKeyedOperatorTest

["Martijn Visser (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/FLINK-29611?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17616866#comment-17616866 ] 

Martijn Visser commented on FLINK-29611:
----------------------------------------

[~sopan98] Are you encountering this on your local machine? This test is being run during every PR, every merged commit and also during the nightly build jobs, but it has never been flaky (else it would have been registered in Jira before).

> Fix flaky tests in CoBroadcastWithNonKeyedOperatorTest
> ------------------------------------------------------
>
>                 Key: FLINK-29611
>                 URL: https://issues.apache.org/jira/browse/FLINK-29611
>             Project: Flink
>          Issue Type: Bug
>            Reporter: Sopan Phaltankar
>            Priority: Minor
>
> The test _org.apache.flink.streaming.api.operators.co.CoBroadcastWithNonKeyedOperatorTest.testMultiStateSupport_ has the following failure:
> Failures:
> [ERROR]   CoBroadcastWithNonKeyedOperatorTest.testMultiStateSupport:74 
> Wrong Side Output: arrays first differed at element [0]; expected:<Record @ 15 : 9:key.6->6> but was:<Record @ 15 : 9:key.5->5>
> I used the tool [NonDex|https://github.com/TestingResearchIllinois/NonDex] to find this flaky test.
> I analyzed the assertion failure and found that the root cause is because the test method calls ctx.getBroadcastState(STATE_DESCRIPTOR).immutableEntries() which calls the entrySet() method of the underlying HashMap. entrySet() returns the entries in a non-deterministic way, causing the test to be flaky. 
> The fix would be to change _HashMap_ to _LinkedHashMap_ where the Map is getting initialized.
> On further analysis, it was found that the Map is getting initialized on line 53 of org.apache.flink.runtime.state.HeapBroadcastState class.
> After changing from HashMap to LinkedHashMap, the above test is passing.



--
This message was sent by Atlassian Jira
(v8.20.10#820010)