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Suresh Srinivas commented on HDFS-3796: --------------------------------------- Todd, do multiple junit tests reuse JVM? If so, you are better off adding this to @BeforeClass and @AfterClass? > Speed up edit log tests by avoiding fsync() > ------------------------------------------- > > Key: HDFS-3796 > URL: https://issues.apache.org/jira/browse/HDFS-3796 > Project: Hadoop HDFS > Issue Type: Improvement > Components: test > Affects Versions: 3.0.0, 2.2.0-alpha > Reporter: Todd Lipcon > Assignee: Todd Lipcon > Priority: Minor > Attachments: hdfs-3796.txt > > > Our edit log tests are very slow because they incur a lot of fsyncs as they > write out transactions. Since fsync() has no effect except in the case of > power outages or system crashes, and we don't care about power outages in the > context of tests, we can safely skip the fsync without any loss in coverage. > In my tests, this sped up TestEditLog by about 5x. The testFuzzSequences test > case improved from ~83 seconds with fsync to about 5 seconds without. These > results are from my SSD laptop - they are probably even more drastic on > spinning media. -- 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