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stack commented on HBASE-4965: ------------------------------ What should I set it too? > Monitor the open file descriptors and the threads counters during the unit > tests > -------------------------------------------------------------------------------- > > Key: HBASE-4965 > URL: https://issues.apache.org/jira/browse/HBASE-4965 > Project: HBase > Issue Type: Improvement > Components: test > Affects Versions: 0.94.0 > Environment: all > Reporter: nkeywal > Assignee: nkeywal > Priority: Minor > Attachments: 4965-v2.txt, 4965-v2.txt, 4965_all.patch, > 4965_all.patch, 4965_all.patch, ResourceChecker.java, > ResourceCheckerJUnitRule.java > > > 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... -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira