From: Shaun Thomas <sthomas@peak6.com>
To: alexandre - aldeia digital <adaldeia@gmail.com>
Cc: undisclosed-recipients:;, <pgsql-performance@postgresql.org>
Subject: Re: Adding more memory = hugh cpu load
Date: Mon, 10 Oct 2011 15:25:54 -0500
Message-ID: <4E9354D2.8010608@peak6.com> (raw)
In-Reply-To: <4E932BFC.7070007@gmail.com>
References: <4E92F294.9010405@gmail.com>
<4E92FB87.1030703@peak6.com>
<4E932BFC.7070007@gmail.com>
On 10/10/2011 12:31 PM, alexandre - aldeia digital wrote:
> <2011-10-10 14:18:48 BRT >LOG: checkpoint complete: wrote 6885 buffers
> (1.1%); 0 transaction log file(s) added, 0 removed, 1 recycled;
> write=29.862 s, sync=28.466 s, total=58.651 s
28.466s sync time?! That's horrifying. At this point, I want to say the
increase in effective_cache_size or shared_buffers triggered the planner
to change one of your plans significantly enough it's doing a ton more
disk IO and starving out your writes. Except you said you changed it
back and it's still misbehaving.
This also reminds me somewhat of an issue Greg mentioned a while back
with xlog storms in 9.0 databases. I can't recall how he usually "fixed"
these, though.
--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
312-676-8870
sthomas@peak6.com
______________________________________________
See http://www.peak6.com/email-disclaimer/ for terms and conditions related to this email
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: sthomas@peak6.com, adaldeia@gmail.com
Subject: Re: Adding more memory = hugh cpu load
In-Reply-To: <4E9354D2.8010608@peak6.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox