Kristian, > andrei.el...@pp.inet.fi writes: > >> Mike, >> >>> Hello, >>> >>> I realize that in general replication from a newer master to an older >>> slave is typically not recommended. This said, does anyone have an >>> experience replicating from MariaDB 10.2 to MySQL 5.6? >> >> A problem that is evident at once is 10.2 GTID events can not be handled >> by 5.6. So at least some filtering should be devised. > > 10.2 does not send GTID to a slave that does not understand it (they are > rewritten on-the-fly to BEGIN query events). So GTID events should not cause > 5.6 slave to break.
Thanks for correcting! The gtid filtering meant is therefore already in the server :-). > > More generally, the code in MariaDB (at least the code that I wrote) detects > what capabilities the slave has, and avoids sending stuff from the master > that an old slave will not understand. See MARIA_SLAVE_CAPABILITY_* in > log_event.h. > > So the intention is that replication to old slave should work. However, this > still requires that applications restrict themselves from using any SQL not > supported on the old slave. And it is only poorly tested, if at all. Hence > the recommendation to avoid new master->old slave. To detail on that for the statement-based replication the old slave may ignore a part of execution context that the new master records into events, typically into Query-log-event. While ignorance is bliss it can lead to inconsistency in this case. Cheers, Andrei _______________________________________________ Mailing list: https://launchpad.net/~maria-discuss Post to : maria-discuss@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-discuss More help : https://help.launchpad.net/ListHelp
