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Hudson commented on CASSANDRA-1954: ----------------------------------- Integrated in Cassandra #751 (See [https://hudson.apache.org/hudson/job/Cassandra/751/]) avoid aquiring (and contending with flush for) flusherlock on each write patch by slebresne; reviewed by jbellis and stuhood for CASSANDRA-1954 > Double-check or replace RRW memtable lock > ----------------------------------------- > > Key: CASSANDRA-1954 > URL: https://issues.apache.org/jira/browse/CASSANDRA-1954 > Project: Cassandra > Issue Type: Improvement > Components: Core > Reporter: Stu Hood > Assignee: Sylvain Lebresne > Priority: Minor > Attachments: > 0001-Double-check-in-maybeSwitchMemtable-to-minimize-writeL.txt, > 0001-Remove-flusherLock-readLock.patch, 1954-v2.txt, 1954_trunk.patch > > > {quote}...when a Memtable reaches its threshold, up to (all) N write threads > will often notice, and race to acquire the writeLock in order to freeze the > memtable. This means that we do way more writeLock acquisitions than we need > to...{quote} > See CASSANDRA-1930 for backstory, but adding double checking inside a read > lock before trying to re-entrantly acquire the writelock would eliminate most > of these excess writelock acquisitions. > Alternatively, we should explore removing locking from these structures > entirely, and replacing the writeLock acquisition with a per-memtable counter > of active threads. -- This message is automatically generated by JIRA. - For more information on JIRA, see: http://www.atlassian.com/software/jira