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  1. HBase
  2. HBASE-4965

Monitor the open file descriptors and the threads counters during the unit tests



    • Improvement
    • Status: Closed
    • Minor
    • Resolution: Fixed
    • 0.94.0
    • 0.94.0
    • test
    • None
    • all

    • Reviewed


      We're seeing a lot of issues with hadoop-qa related to threads or file descriptors.
      Monitoring these counters would ease the analysis.

      Note as well that

      • if we want to execute the tests in the same jvm (because the test is small or because we want to share the cluster) we can't afford to leak too many resources
      • if the tests leak, it's more difficult to detect a leak in the software itself.

      I attach piece of code that I used. It requires two lines in a unit test class to:

      • before every test, count the threads and the open file descriptor
      • after every test, compare with the previous value.

      I ran it on some tests; we have for example:

      • client.TestMultiParallel#testBatchWithManyColsInOneRowGetAndPut: 232 threads (was 231), 390 file descriptors (was 390). => TestMultiParallel uses 232 threads!
      • client.TestMultipleTimestamps#testWithColumnDeletes: 152 threads (was 151), 283 file descriptors (was 282).
      • client.TestAdmin#testCheckHBaseAvailableClosesConnection: 477 threads (was 294), 815 file descriptors (was 461)
      • client.TestMetaMigrationRemovingHTD#testMetaMigration: 149 threads (was 148), 310 file descriptors (was 307).

      It's not always leaks, we can expect some pooling effects. But still...


        1. ResourceChecker.java
          4 kB
          Nicolas Liochon
        2. ResourceCheckerJUnitRule.java
          1 kB
          Nicolas Liochon
        3. 4965_all.patch
          158 kB
          Nicolas Liochon
        4. 4965_all.patch
          158 kB
          Nicolas Liochon
        5. 4965_all.patch
          158 kB
          Michael Stack
        6. 4965-v2.txt
          159 kB
          Michael Stack
        7. 4965-v2.txt
          159 kB
          Michael Stack
        8. 4965-v3.txt
          159 kB
          Michael Stack

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              nkeywal Nicolas Liochon
              nkeywal Nicolas Liochon
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