Hi, MDEV ticket for this task https://jira.mariadb.org/browse/MDEV-11675
Regards sachin On Thu, Dec 29, 2016 at 3:08 PM, Sachin Setiya <[email protected]> wrote: > Hello everyone! > > I am thinking of implementing true lock=none for slaves. Currently > Alter command is only executed on slave when master commits it. > I(thanks marko for suggesting this idea) am thinking of writing > BEGIN_DDL_EVENT in binlog after master hits ha_prepare_inplace_alter_table. > Then master will write QUERY_EVENT on binlog with actual alter query . > On commit/rollback master will write COMMIT_DDL_EVENT/ROLLBACK_DDL_EVENT. > > On slave there will be pool of threads(configurable global variable), which > will apply these DDLs. On receiving BEGIN_DDL_EVENT slave thread will pass the > QUERY_EVENT to one of the worker thread. Worker thread will execute until > ha_inplace_alter_table. Actual commit_inplace_alter will be called by > sql thread. > If sql thread recieve some kind of rollback event , then it will somehow > signal > worker thread to stop executing alter. If none of the worker threads > are available > then event will be en-queued, then If we received rollback event the > we will simply > discard event from queue, If we received commit event then SQL thread > will synchronously > process DDL event. > > Please let me know what you think. > Credits for idea Marko and Lixun. > > > Regards > sachin _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
