[ https://issues.apache.org/jira/browse/HBASE-7336?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13534149#comment-13534149 ]
Lars Hofhansl commented on HBASE-7336: -------------------------------------- The 0.94 tests fail with the same OOM even without this patch, so I am going to reapply. Sorry for the noise, but I had to make sure. > HFileBlock.readAtOffset does not work well with multiple threads > ---------------------------------------------------------------- > > Key: HBASE-7336 > URL: https://issues.apache.org/jira/browse/HBASE-7336 > Project: HBase > Issue Type: Sub-task > Reporter: Lars Hofhansl > Assignee: Lars Hofhansl > Priority: Critical > Fix For: 0.96.0, 0.94.4 > > Attachments: 7336-0.94.txt, 7336-0.96.txt > > > HBase grinds to a halt when many threads scan along the same set of blocks > and neither read short circuit is nor block caching is enabled for the dfs > client ... disabling the block cache makes sense on very large scans. > It turns out that synchronizing in istream in HFileBlock.readAtOffset is the > culprit. -- 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