| From: | Marcello Perathoner <marcello(at)perathoner(dot)de> |
|---|---|
| To: | Dennis Brouwer <dennis(dot)brouwer(at)m4n(dot)nl> |
| Cc: | pgsql-admin(at)postgresql(dot)org |
| Subject: | Re: CPU causes 100% load in user space when ntp client runs and postgresql is under heavy load |
| Date: | 2012-09-24 21:05:03 |
| Message-ID: | 5060CAFF.8040203@perathoner.de |
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| Lists: | pgsql-admin |
On 09/24/2012 03:53 PM, Dennis Brouwer wrote:
> Last week I was repeatedly able to run all these tests on the database
> without any issue but recently, all of a sudden at random, some of the
> queries performed a factor 100 less. It may take hours to complete the
> transaction. At the same moment we see a dramatic decrease in IO and the
> CPU is nearly 100% busy in user space.
>
> After days of testing I may have found the cause: the ntp client. If I stop
> the ntp client the problem vanishes.
Any chance you are hitting this known linux bug in conjunction with a
misconfigured ntp server? ie. does a
# date -s now
fix the cpu load?
--
Marcello Perathoner
webmaster(at)gutenberg(dot)org
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