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

[Steven Crandell]

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.

-s

On Tue, Nov 24, 2009 at 4:38 AM, Glyn Astill <glynastill at yahoo.co.uk> wrote:

>
>
> --- On Tue, 24/11/09, Aleksey Tsalolikhin <atsaloli.tech at gmail.com> wrote:
>
> > From: Aleksey Tsalolikhin <atsaloli.tech at gmail.com>
> > Subject: [Pgpool-general] pgpool-II 2.2.5 slamming the CPU
> > To: pgpool-general at pgfoundry.org
> > Date: Tuesday, 24 November, 2009, 0:26
> > Hi.  We have our pgpool-II
> > configured with
> >
> > num_init_children = 64
> >
> > and I see the number of processes in the run queue goes
> > from nothing to 64
> > then to nothing again; this causes the load average to
> > spike sharply which
> > rings alarm bells in the monitoring system.
> >
> > I don't suppose it's possible to spread this workload out a
> > bit so it does not
> > spike so sharp?
> >
> >
>
> Out of interest, what kernel are you on?
>
>
>
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