[MAPREDUCE-7064] Flaky test TestTaskAttempt#testReducerCustomResourceTypes

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.1.0, 3.0.3
• Component/s: client, test
• Hadoop Flags: Reviewed
• Assignee: Peter Bacsko
• Reporter: Peter Bacsko
• Created: 12/Mar/18 14:21
• Updated: 05/Apr/18 20:17
• Resolved: 14/Mar/18 20:24

Description

The test TestTaskAttempt#testReducerCustomResourceType can occasionally fail with the following error:

org.apache.hadoop.yarn.exceptions.ResourceNotFoundException: Unknown resource 'a-custom-resource'. Known resources are [name: memory-mb, units: Mi, type: COUNTABLE, value: 0, minimum allocation: 0, maximum allocation: 9223372036854775807, name: vcores, units: , type: COUNTABLE, value: 0, minimum allocation: 0, maximum allocation: 9223372036854775807]
	at org.apache.hadoop.mapreduce.v2.app.job.impl.TestTaskAttempt.createReduceTaskAttemptImplForTest(TestTaskAttempt.java:434)
	at org.apache.hadoop.mapreduce.v2.app.job.impl.TestTaskAttempt.testReducerCustomResourceTypes(TestTaskAttempt.java:1535)

The root cause seems to be an interference from previous tests that start instance(s) of FailingAttemptsMRApp or FailingAttemptsDuringAssignedMRApp. When I disabled these tests, testReducerCustomResourceTypes always passed.