maria-developers team mailing list archive

[Sergey Vojtovich <svoj@xxxxxxxxxxx>]

Hi Sergei,

On Mon, Nov 23, 2015 at 10:44:39AM +0100, Sergei Golubchik wrote:
> Hi, Sergey!
> 
> On Nov 23, Sergey Vojtovich wrote:
> > On Mon, Nov 23, 2015 at 10:00:33AM +0100, Sergei Golubchik wrote:
> > > On Nov 23, Sergey Vojtovich wrote:
> > > 
> > > Could there be any other fix for P_S autosizing besides moving all its
> > > dependencies to early options?
> > No simple solution on my mind. May be initialize PFS with defaults and
> > then reinitialize with real values?
> 
> perfschema creates fixed-size (*) arrays based on these values. And
> allocates data mutexes, rwlocks, conditions there.
> 
> if perfschema data structures are re-initialized, all mutexes/etc have
> to be. That's why Marc has created these "early options" in the
> first place. To reinitialize only those few mutexes that my_getopt
> needs, not half of the server.
> 
> Regards,
> Sergei
> 
> (*) I have a vague recollection that this could've been changed (may be
> partially) in 5.7.
All I can see now is 19 PFS variables depending on table_definition_cache &&
table_open_cache && max_connections && open_files_limit values. I couldn't
easily track down further dependencies, at least number of allocated arrays
basing on these variables is far over 19.

Could you confirm that:
1. we want to fix PFS autosizing along with this patch
2. we want to avoid early initialization of these 4 server variables and
   instead reinitialize PFS when they're autosized

Thanks,
Sergey