Re: Occasional giant spikes in CPU load

On 6/24/10 9:04 PM, Tom Lane wrote:
> Craig James<craig_james(at)emolecules(dot)com> writes:
>> So what is it that will cause every single Postgres backend to come to life at the same moment, when there's no real load on the server? Maybe if a backend crashes? Some other problem?
>
> sinval queue overflow comes to mind ... although that really shouldn't
> happen if there's "no real load" on the server. What PG version is
> this?

8.3.10. Upgraded based on your advice when I first asked this question.

> Also, the pg_stat_activity view contents when this happens would
> probably be more useful to look at than "top" output.

I'll try. It's hard to discover anything because the whole machine is overwhelmed when this happens. The only way I got the top(1) output was by running it high priority as root using nice(1). I can't do that with a Postgres backend, but I'll see what I can do.

Craig