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March 2014

46 participants
92 discussions

Re: [Maria-developers] MariaDB Master Replication To MySQL
by Kristian Nielsen 03 Mar '14

03 Mar '14

> In this particular case, we have someone that wants to use MariaDB 10.0 master with a MySQL 5.6 slave. But they are running into a problem with GTID. Generally, the recommended setup is to only replicate from old version on master to new (or same) version on slave. Replicating from new master to old slave in general is hard to support 100%, as there may be eg. new SQL syntax on the master that is impossible for the old version slave to execute. That being said, the intention is that replication from new master to old slave (like MariaDB 10.0 -> MySQL 5.6) should work in most reasonable cases. So this sounds like a bug which might be worth filing. > 2.) Is it possible to disable GTID in 10.0? It seems like it would break a few other things like parallel replication, but they're only running MariaDB on the master. GTID is disabled automatically when the slave does not support it. The code rewrites the binlog stream on the fly to remove events that are not supported on the old slave, and replace them with something appropriate for that slave version. Does the same problem occur when replicating from MariaDB 10.0 master to MariaDB 5.5 slave? What about when replicating from MySQL 5.5 master to MySQL 5.6 slave? - Kristian.

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Re: [Maria-developers] MDEV-5755 - Scalability: let LOCK_open and THR_LOCK::mutex be normal mutexes
by Sergei Golubchik 03 Mar '14

03 Mar '14

Hi, Sergey! On Feb 27, Sergey Vojtovich wrote: > At lp:maria/10.0 > > ------------------------------------------------------------ > revno: 4011 > revision-id: svoj(a)mariadb.org-20140227141521-fgj5b0h3qbijyojh > parent: svoj(a)mariadb.org-20140220072533-l3au3y7mrsyclfpb > committer: Sergey Vojtovich <svoj(a)mariadb.org> > branch nick: 10.0 > timestamp: Thu 2014-02-27 18:15:21 +0400 > message: > MDEV-5755 - Scalability: let LOCK_open and THR_LOCK::mutex be normal mutexes > > Normal mutexes scale better than adaptive at high thread count. > At low thread count they behave similarly. To summarize Axel results: at low concurency normal can be ~1% slower. at high concurrency r/o - normal are up to 25% faster. at high concurrency r/w - normal are up to 10% slower. That last result bothers me a litte. Regards, Sergei

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