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Lars Hofhansl commented on HBASE-6603: -------------------------------------- Sure. Just make a 0.94/0.96 patch there. Patch there looks good to me. (copykv is gone now, though). > RegionMetricsStorage.incrNumericMetric is called too often > ---------------------------------------------------------- > > Key: HBASE-6603 > URL: https://issues.apache.org/jira/browse/HBASE-6603 > Project: HBase > Issue Type: Bug > Components: performance > Reporter: Lars Hofhansl > Assignee: Lars Hofhansl > Fix For: 0.96.0, 0.94.2 > > > Running an HBase scan load through the profiler revealed that > RegionMetricsStorage.incrNumericMetric is called way too often. > It turns out that we make this call for *each* KV in StoreScanner.next(...). > Incrementing AtomicLong requires expensive memory barriers. > The observation here is that StoreScanner.next(...) can maintain a simple > long in its internal loop and only update the metric upon exit. Thus the > AtomicLong is not updated nearly as often. > That cuts about 10% runtime from scan only load (I'll quantify this better > soon). -- 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