Hi Julien, On Mon, Sep 21, 2020 at 6:13 PM Julien Muchembled <[email protected]> wrote: > I hoped to get an answer about how to tell InnoDB to complete its background > tasks as soon as possible (even if background activity has no impact on perf, > not having to wait so long to make a clean backup of the datadir remains > useful) but I guess there's no way. Should I open a task issue on JIRA ?
We already have https://jira.mariadb.org/browse/MDEV-22958 filed for adding a SET GLOBAL statement that would wait for the purge to be finished. (Admittedly, the title of the bug is misleading, referring to a test timeout on our CI system.) > After further analysis, we found that the deadlocks are due to a problem in > our application. We have a scheduler that uses MariaDB to store tasks and the > performance profile of the new hardware is so unusual that some kinds of > tasks accumulated to a point that the scheduler couldn't handle. So, is there anything that you would still want to diagnose? I would recommend reading https://mysqlentomologist.blogspot.com/2020/09/dynamic-tracing-of-pthreadmutexlock-in.html and watching the MariaDB Fest 2020 recording of Valerii’s talk. There is also the command "offcputime" which should be similar to "perf" but counting waits. http://www.brendangregg.com/offcpuanalysis.html shows how to combine it with flame graphs. I do not have any hands-on experience on these techniques yet. Marko -- Marko Mäkelä, Lead Developer InnoDB MariaDB Corporation _______________________________________________ Mailing list: https://launchpad.net/~maria-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-discuss More help : https://help.launchpad.net/ListHelp
