On Tue, Nov 28, 2023 at 8:27 AM jai <jaimin@xxxxxxxxxx> wrote:
I am able to set cpulimit, iolimit, etc for a process using its pid through cgroups v2. But for some threads of a single mysql process, how can I achieve that?
You cannot; 1) the limits are per-cgroup and the entire service is a single cgroup; 2) the threads are created by mysqld, not by systemd, and systemd does not monitor and move service processes across cgroups once the service is already running; 3) afaik, in cgroups v2 it isn't even allowed for threads of a single process to straddle multiple cgroups anymore.
I'm not a DBA but I've heard that one common way to handle this would be to create a separate MySQL instance (probably on a separate machine, even) that would replicate all the data, for the heavy users to query. (Or the other way around, main instance for the heavy updates ⇒ replica for regular queries.)
--
Mantas Mikulėnas
