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  1. Derby
  2. DERBY-5471

Stress test for identity columns and sequence seem to be taking longer on trunk compared to RC3



    • Type: Task
    • Status: Closed
    • Priority: Major
    • Resolution: Cannot Reproduce
    • Affects Version/s:
    • Fix Version/s: None
    • Component/s: Test
    • Labels:
    • Environment:
    • Bug behavior facts:


      I have been trying to run org.apache.derbyTesting.perf.clients.Runner (which provides ways to stress test sequence generator and identity columns) on trunk and RC3 to compare the performance and I find that it takes almost double the time for the tests to finish on trunk. Additionally, the identity column test consistently ran into lock timeouts on trunk. I am running with insane jars on trunk and RC3. The test in question is not in official jars for the release candidate so I manually copied them to RC3 environment during my test(basically copied the entire org.apache.derbyTesting.perf.clients.Runner directory from trunk to RC3 environment).

      Command to do sequence stress testing is as follows
      java org.apache.derbyTesting.perf.clients.Runner -driver org.apache.derby.jdbc.EmbeddedDriver -init -load seq_gen -load_opts debugging=1,numberOfGenerators=5,tablesPerGenerator=10,insertsPerTransaction=100,identityTest=0 -gen b2b -threads 10

      Command to do identity column stress testing is as follows
      time java org.apache.derbyTesting.perf.clients.Runner -driver org.apache.derby.jdbc.EmbeddedDriver -init -load seq_gen -load_opts debugging=1,numberOfGenerators=5,tablesPerGenerator=10,insertsPerTransaction=100,identityTest=1 -gen b2b -threads 10

      An average run on RC3 for sequence stress test is about a minute and 46 secs. On trunk, on an average it takes 2 and half minutes

      An average run on RC3 for identity stress test is about a minute and 50 secs. On trunk, on an average it takes 3minsutes and 30 secs. Also, on trunk, this test runs into lock timeouts.

      I was wondering if this is the right behavior. The performance should be better in trunk because of pre-allocation of range for sequences and identity columns(which defaults to 20) but unless I have missed something in my tests, the results don't show the performance improvement.


        1. 5471-performance.html
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          Richard N. Hillegas

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              • Assignee:
                mamtas Mamta A. Satoor
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