On Thu, 2010-06-24 at 17:50 -0700, Craig James wrote:
> I'm reviving this question because I never figured it out.  To summarize: At 
> random intervals anywhere from a few times per hour to once or twice a day, 
> we see a huge spike in CPU load that essentially brings the system to a halt 
> for up to a minute or two.  Previous answers focused on "what is it doing", 
> i.e. is it really Postgres or something else?
> 
> Now the question has narrowed down to this: what could trigger EVERY postgres 
> backend to do something at the same time?  See the attached output from "top 
> -b", which shows what is happening during one of the CPU spikes.

checkpoint causing IO Wait.

What does sar say about these times?

Joshua D. Drake


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