Re: Higher load averages running mysql on 15 instead fo 14

You could post more information about the system.

Something which pops up in my mind is that it might be interesting if it is a NUMA system.
https://en.wikipedia.org/wiki/Non-uniform_memory_access
Maybe locks use memory of other zones/nodes.

Is it possible to get the output of "procstat -kk <pid-of-mysqld>" when it is contending on these locks? That would show if it is waiting in the kernel or not.

Regards,
Ronald.

 
Van: Pete French <[email protected]>
Datum: woensdag, 4 februari 2026 11:19
Aan: [email protected]
Onderwerp: Re: Higher load averages running mysql on 15 instead fo 14
> 
> 
> On 03/02/2026 18:19, Pete Wright wrote:
> > which filesystem is your mysql data mounted on?  my fist suspect would > be some performance change in the underlying filesystem, or how data is > cached in memory.  systat may help shed light on this with maybe the > vmstat, iolat or iostat options.
> 
> Its on ZFS, and that was my first thought as well, as the version of
> ZFS did change between 14 and 15, and all the non running threads
> seem to be in either kread or uwait state. But after some reading
> around it doesn't look as if mysql is using the filesystem for these
> kind of locks.
> 
> > do you have a similar system running 14.x available for comparison > purposes?
> 
> Unfortunately not :-(
> 
> However, your suggestion of other things to look at are super helpful.
> I often forget we have all these other tools available ;) thanks!
> 
> -pete. [ off to re-read the man page for systat etc.. ]
>  
> 
> 
>