[FLINK-1432] CombineTaskTest.testCancelCombineTaskSorting sometimes fails

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.9
• Assignee: Stephan Ewen
• Reporter: Robert Metzger
• Created: 22/Jan/15 10:05
• Updated: 12/Feb/15 11:20
• Resolved: 12/Feb/15 11:20

Description

We have a bunch of tests which fail only in rare cases on travis.

https://s3.amazonaws.com/archive.travis-ci.org/jobs/47783455/log.txt

Exception in thread "Thread-17" java.lang.AssertionError: Canceling task failed: java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:859)
	at java.util.ArrayList$Itr.next(ArrayList.java:831)
	at org.apache.flink.runtime.memorymanager.DefaultMemoryManager.release(DefaultMemoryManager.java:290)
	at org.apache.flink.runtime.operators.GroupReduceCombineDriver.cancel(GroupReduceCombineDriver.java:221)
	at org.apache.flink.runtime.operators.testutils.DriverTestBase.cancel(DriverTestBase.java:272)
	at org.apache.flink.runtime.operators.testutils.TaskCancelThread.run(TaskCancelThread.java:60)

	at org.junit.Assert.fail(Assert.java:88)
	at org.apache.flink.runtime.operators.testutils.TaskCancelThread.run(TaskCancelThread.java:68)
java.lang.NullPointerException
	at org.apache.flink.runtime.memorymanager.DefaultMemoryManager.release(DefaultMemoryManager.java:291)
	at org.apache.flink.runtime.operators.GroupReduceCombineDriver.cleanup(GroupReduceCombineDriver.java:213)
	at org.apache.flink.runtime.operators.testutils.DriverTestBase.testDriverInternal(DriverTestBase.java:245)
	at org.apache.flink.runtime.operators.testutils.DriverTestBase.testDriver(DriverTestBase.java:175)
	at org.apache.flink.runtime.operators.CombineTaskTest$1.run(CombineTaskTest.java:143)
Tests run: 6, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 2.172 sec <<< FAILURE! - in org.apache.flink.runtime.operators.CombineTaskTest
testCancelCombineTaskSorting[0](org.apache.flink.runtime.operators.CombineTaskTest)  Time elapsed: 1.023 sec  <<< FAILURE!
java.lang.AssertionError: Exception was thrown despite proper canceling.
	at org.junit.Assert.fail(Assert.java:88)
	at org.junit.Assert.assertTrue(Assert.java:41)
	at org.apache.flink.runtime.operators.CombineTaskTest.testCancelCombineTaskSorting(CombineTaskTest.java:162)