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Hi Kristian,I've just tried your tokudb_optimistic_parallel_replication branch, and it behaves very strangely: the SQL thread stop by itself without any replication error when the parallel_mode is set to optimistic.
In the error.log :2016-12-09 11:48:05 140259564768000 [Note] Slave I/O thread: connected to master 'repl@172.16.4.1:3306',replication starts at GTID position '0-1-482499150' 2016-12-09 11:48:05 140259546905344 [Note] Slave SQL thread initialized, starting replication in log 'mysql-bin.001443' at position 973807119, relay log './sql-slave-relay-bin.000001' position: 4; GTID position '0-1-482499150' 2016-12-09 11:50:29 140259546905344 [Note] Error reading relay log event: slave SQL thread was killed 2016-12-09 11:50:29 140259564768000 [Note] Slave I/O thread exiting, read up to log 'mysql-bin.001443', position 1041861449; GTID position 0-1-482509090 2016-12-09 11:50:43 140259546905344 [Note] Slave I/O thread: connected to master 'repl@172.16.4.1:3306',replication starts at GTID position '0-1-482509090' 2016-12-09 11:50:43 140259548117760 [Note] Slave SQL thread initialized, starting replication in log 'mysql-bin.001443' at position 1041861449, relay log './sql-slave-relay-bin.000001' position: 4; GTID position '0-1-482509090' 2016-12-09 11:50:45 140259548117760 [Note] Error reading relay log event: slave SQL thread was killed 2016-12-09 11:52:03 140259547511552 [Note] Slave SQL thread initialized, starting replication in log 'mysql-bin.001443' at position 1046751490, relay log './sql-slave-relay-bin.000002' position: 4890750; GTID position '0-1-482509269' 2016-12-09 11:52:05 140259547511552 [Note] Slave SQL thread exiting, replication stopped in log 'mysql-bin.001443' at position 1047219058; GTID position '0-1-482509775'
Switching back to conservative mode, and all is working properly. Any idea what could be wrong?
Thanks! Jocelyn Fournier Founder M : +33 6 51 21 54 10 https://www.softizy.com Softizy - At your side to Optimize your PHP / MySQL applications Le 28/11/2016 à 10:10, Kristian Nielsen a écrit :
Parallel replication so far did not work well with TokuDB, as some people who tried it found out. I have now pushed to 10.1 some patches to solve the problems. There are two main fixes: 1. Fix some races where a waiting transaction would miss its wakeup and get a lock timeout on a waiting row lock, even though the lock was released by the holding transaction. This fix is due to great work by Rich Prohaska. This problem is actually not specific to replication, normal transactions on a master will experience it too. But it hurts replication a lot, since replication must commit transactions in order, so one stalled transaction stalls all following transactions as well. 2. Implement the conflict detection and handling necessary for optimistic parallel replication to work. This basically implements thd_rpl_deadlock_check() and hton->kill_query methods. This should solve the problems where optimistic parallel replication with TokuDB breaks with lock wait timeouts. If someone wants to test it, I have made a tree available with just these fixes on top of MariaDB 10.1.19: https://github.com/knielsen/server/tree/tokudb_optimistic_parallel_replication The fix should appear in 10.1.20 eventually. The first part of the patch has also been submitted by Rich to upstream. When this is (hopefully) merged upstream, and upstream merged into MariaDB, the MariaDB version of the fix should be replaced with the Percona one. I tried making the MariaDB version of the fix identical to Rich's pull request and keeping it in a separate commit, so this should hopefully be simple to do when the time comes. - Kristian. _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : maria-developers@xxxxxxxxxxxxxxxxxxx Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
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