[YARN-9025] TestFairScheduler#testChildMaxResources is flaky

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.3.0
• Fix Version/s: 3.3.0
• Hadoop Flags: Reviewed
• Assignee: Szilard Nemeth
• Reporter: Szilard Nemeth
• Created: 15/Nov/18 17:43
• Updated: 26/Feb/20 05:29
• Resolved: 06/Dec/18 00:48

Description

During making the code patch for YARN-8059, I come across a flaky test, see this link: https://builds.apache.org/job/PreCommit-YARN-Build/22412/artifact/out/patch-unit-hadoop-yarn-project_hadoop-yarn_hadoop-yarn-server_hadoop-yarn-server-resourcemanager.txt

This is the error message:

[ERROR] Tests run: 108, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 19.37 s <<< FAILURE! - in org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.TestFairScheduler
[ERROR] testChildMaxResources(org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.TestFairScheduler) Time elapsed: 0.164 s <<< FAILURE!
java.lang.AssertionError: App 1 is not running with the correct number of containers expected:<2> but was:<0>
 at org.junit.Assert.fail(Assert.java:88)

So the thing is, even if we had 8 node updates, due to the nature of how we handle the events, it can happen that no container is allocated for the application.

Issue Links

• is depended upon by: YARN-8059 Resource type is ignored when FS decide to preempt