intermittent failures of TestTimeLimitedCollector.testTimeoutMultiThreaded in nightly tests

• Key: LUCENE-1238
• Type: Bug
• Status: Resolved
• Resolution: Fixed
• Priority: Minor
• Assignee: Doron Cohen
• Reporter: Doron Cohen
• Affects Version/s: 2.4

Description

Occasionly TestTimeLimitedCollector.testTimeoutMultiThreaded fails. e.g. with this output:

   [junit] ------------- Standard Error -----------------
   [junit] Exception in thread "Thread-97" junit.framework.AssertionFailedError: no hits found!
   [junit]     at junit.framework.Assert.fail(Assert.java:47)
   [junit]     at junit.framework.Assert.assertTrue(Assert.java:20)
   [junit]     at org.apache.lucene.search.TestTimeLimitedCollector.doTestTimeout(TestTimeLimitedCollector.java:152)
   [junit]     at org.apache.lucene.search.TestTimeLimitedCollector.access$100(TestTimeLimitedCollector.java:38)
   [junit]     at org.apache.lucene.search.TestTimeLimitedCollector$1.run(TestTimeLimitedCollector.java:231)
   [junit] Exception in thread "Thread-85" junit.framework.AssertionFailedError: no hits found!
   [junit]     at junit.framework.Assert.fail(Assert.java:47)
   [junit]     at junit.framework.Assert.assertTrue(Assert.java:20)
   [junit]     at org.apache.lucene.search.TestTimeLimitedCollector.doTestTimeout(TestTimeLimitedCollector.java:152)
   [junit]     at org.apache.lucene.search.TestTimeLimitedCollector.access$100(TestTimeLimitedCollector.java:38)
   [junit]     at org.apache.lucene.search.TestTimeLimitedCollector$1.run(TestTimeLimitedCollector.java:231)
   [junit] ------------- ---------------- ---------------
   [junit] Testcase: testTimeoutMultiThreaded(org.apache.lucene.search.TestTimeLimitedCollector):      FAILED
   [junit] some threads failed! expected:<50> but was:<48>
   [junit] junit.framework.AssertionFailedError: some threads failed! expected:<50> but was:<48>
   [junit]     at org.apache.lucene.search.TestTimeLimitedCollector.doTestMultiThreads(TestTimeLimitedCollector.java:255)
   [junit]     at org.apache.lucene.search.TestTimeLimitedCollector.testTimeoutMultiThreaded(TestTimeLimitedCollector.java:220)
   [junit]

Problem either in test or in TimeLimitedCollector.

Comments

[Doron Cohen]

fixed typo in summary.

[Doron Cohen]

Problem was in test.

However fix adds a greediness option to time-limited-collector (TLC):

• A greedy TLC upon timeout would allow the wrapped collector to
  collect current doc and only then throw the timeout exception.
• A non greedy TLC (the default, as before) will immediately throw the exception.

For the test, setting to greedy allows to require that at least one doc was collected.

I addition this patch:

• Adds missing javadocs for TLC constructor.
• Increase "slack" in timeout requirements in the test.
  This is to prevent further noise in this:
  HLC is required to timeout "not too soon and not too late", but in a busy machine
  the "not too late" part is problematic to test.
  I considered to removing this part (not too late), but decided to leave it in for now.
• Adds a test for the setGreedy() option.

All TLC tests pass.

[Doron Cohen]

I intend to commit this later today.

[Doron Cohen]

Committed.