Is it reasonable for semi-sync to need to lock/unlock LOCK_plugin that frequently? The plugin architecture, like most of the rest of MySQL, wasn't described to people on the outside (like me).
On Mon, Aug 19, 2013 at 6:32 AM, Pavel Ivanov <piva...@google.com> wrote: > On Mon, Aug 19, 2013 at 5:17 AM, Roberto Spadim <robe...@spadim.com.br> > wrote: > > hi! > > > >> Another plugin that should be disabled is QUERY_RESPONSE_TIME. It has > quite > >> some impact on LOCK_plugin: > >> > >> -DWITH_QUERY_RESPONSE_TIME=1 > >> > >> > +-----------------------------------------+------------+-----------------+ > >> | event_name | count_star | sum_timer_wait > | > >> > +-----------------------------------------+------------+-----------------+ > >> | wait/synch/mutex/sql/LOCK_open | 2743723 | > 160451183703111 | > >> | wait/synch/mutex/mysys/THR_LOCK::mutex | 2743651 | > 19122327109683 | > >> | wait/synch/mutex/sql/LOCK_plugin | 3135747 | > 18611700478728 | > >> | wait/synch/rwlock/sql/LOCK_tdc | 1356784 | > 1360918935810 | > >> > >> -DWITHOUT_QUERY_RESPONSE_TIME=1 > >> > >> completely removes LOCK_plugin from the top 20 list. This is also > considered > >> a bug as the plugin API should be lightweight. > >> > > > > Should the > > "SET GLOBAL query_response_time_stats=0" > > solve this contention problem? or the LOCK_plugin is called always, > > doesn't matter if it's "disabled" or not? > > If it's implemented the same way as semisync plugins (and it should be > implemented like that) then LOCK_plugin is locked even when plugin's > functionality disabled, because it gets disabled using plugin-specific > variable which can be checked only inside the plugin code. > > > Pavel > > _______________________________________________ > Mailing list: https://launchpad.net/~maria-developers > Post to : maria-developers@lists.launchpad.net > Unsubscribe : https://launchpad.net/~maria-developers > More help : https://help.launchpad.net/ListHelp > -- Mark Callaghan mdcal...@gmail.com
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