[Pgpool-general] pgpool-II 2.2.5 slamming the CPU

[Denis Gasparin]

We have the problems with 2.6.16 and 2.6.18 kernels...
I'm not sure it is a kernel related problem...

Denis

Il giorno 25/nov/2009, alle ore 11.46, Glyn Astill ha scritto:

> --- On Tue, 24/11/09, Steven Crandell <steven.crandell at gmail.com> wrote:
>> I'm seeing this also with
>> pgpool-II-2.2.5 running on ubuntu server, kernel 2.6.24.
>> Given pgpool's handling method for connections over the
>> num_init_children (queuing), I have to set num_init_children
>> high enough to ensure children are never depleted (>
>> 1000).
>> 
>> When all those children respawn every $child_life_time
>> seconds I see load spikes upwards of 60
>> 
>> That said, there does not appear to be any operational
>> impact on the pgpool server, I am just seeing load spikes
>> similar to what Aleksey mentioned turning my monitoring
>> solution red multiple times a day.
>> 
>> 
>> I would think that one work around would be to set
>> child_max_connections sufficiently low that children respawn
>> because they have reached child_max_connections rather than
>> than child_life_time.  If I'm understanding the
>> situation correctly this would cause child respawns to
>> happen more serially rather than all children respawning
>> together every $child_life_time seconds.
>> 
> 
> Hmm, the reason I asked about kernel version was that I started seeing these spikes after going from 2.6.18 to 2.6.26, that's not to say more subtle symptoms were not there before and I didn't notice.
> 
> I'm jumping to conclusions that it could be CFS related, and that would make sense for 2.6.24 too .... but I'm pretty much totally uninformed on that.
> 
> 
> 
> 
> 
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