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Ted Yu commented on HBASE-5778: ------------------------------- bq. is there anything in particular you think needs more explanation? No. bq. If you change SLEEP_TIME for 1500, does it still fail? If not, that's the IPV6 problem. {code} Running org.apache.hadoop.hbase.replication.TestMasterReplication Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 80.499 sec {code} > Turn on WAL compression by default > ---------------------------------- > > Key: HBASE-5778 > URL: https://issues.apache.org/jira/browse/HBASE-5778 > Project: HBase > Issue Type: Improvement > Reporter: Jean-Daniel Cryans > Assignee: Jean-Daniel Cryans > Priority: Blocker > Fix For: 0.96.0 > > Attachments: 5778.addendum, 5778-addendum.txt, HBASE-5778-0.94.patch, > HBASE-5778-0.94-v2.patch, HBASE-5778-0.94-v3.patch, HBASE-5778-0.94-v4.patch, > HBASE-5778-0.94-v5.patch, HBASE-5778-0.94-v6.patch, HBASE-5778.patch, > HBASE-5778-trunk-v6.patch > > > I ran some tests to verify if WAL compression should be turned on by default. > For a use case where it's not very useful (values two order of magnitude > bigger than the keys), the insert time wasn't different and the CPU usage 15% > higher (150% CPU usage VS 130% when not compressing the WAL). > When values are smaller than the keys, I saw a 38% improvement for the insert > run time and CPU usage was 33% higher (600% CPU usage VS 450%). I'm not sure > WAL compression accounts for all the additional CPU usage, it might just be > that we're able to insert faster and we spend more time in the MemStore per > second (because our MemStores are bad when they contain tens of thousands of > values). > Those are two extremes, but it shows that for the price of some CPU we can > save a lot. My machines have 2 quads with HT, so I still had a lot of idle > CPUs. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira