----------------------------------------------------------------------- WORKLOG TASK -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- TASK...........: Efficient group commit for binary log CREATION DATE..: Mon, 26 Apr 2010, 13:28 SUPERVISOR.....: Knielsen IMPLEMENTOR....: COPIES TO......: CATEGORY.......: Server-RawIdeaBin TASK ID........: 116 (http://askmonty.org/worklog/?tid=116) VERSION........: Server-9.x STATUS.........: Un-Assigned PRIORITY.......: 60 WORKED HOURS...: 0 ESTIMATE.......: 0 (hours remain) ORIG. ESTIMATE.: 0 PROGRESS NOTES: DESCRIPTION: Currently, in order to ensure that the server can recover after a crash to a state in which storage engines and binary log are consistent with each other, it is necessary to use XA with durable commits for both storage engines (innodb_flush_log_at_trx_commit=1) and binary log (sync_binlog=1). This is _very_ expensive, since the server needs to do three fsync() operations for every commit, as there is no working group commit when the binary log is enabled. The idea is to - Implement/fix group commit to work properly with the binary log enabled. - (Optionally) avoid the need to fsync() in the engine, and instead rely on replaying any lost transactions from the binary log against the engine during crash recovery. For background see these articles: http://kristiannielsen.livejournal.com/12254.html http://kristiannielsen.livejournal.com/12408.html http://kristiannielsen.livejournal.com/12553.html ESTIMATED WORK TIME ESTIMATED COMPLETION DATE ----------------------------------------------------------------------- WorkLog (v3.5.9)