From: Gerhard Wohlgenannt <wohlg@ai.wu.ac.at>
To: Tomas Vondra <tv@fuzzy.cz>
Cc: Andy Colson <andy@squeakycode.net>
Cc: pgsql-performance@postgresql.org, Heinz-Peter Lang <heinz@langatium.net>
Cc: Gerhard Wohlgenannt <wohlg@ai.wu-wien.ac.at>
Cc: Weichselbraun, Albert <albert.weichselbraun@wu.ac.at>
Subject: Re: Sudden drop in DBb performance
Date: Tue, 06 Sep 2011 10:32:09 +0200
Message-ID: <4E65DA89.2030106@ai.wu.ac.at> (raw)
In-Reply-To: <cc2305e664bc05f72ce55eaf7c18db63.squirrel@sq.gransy.com>
References: <4E61D6B4.9090804@ai.wu.ac.at>
<33fadeb6ac1bade5ef01bd08d1fd7807.squirrel@sq.gransy.com>
<4E64D3D3.8000205@squeakycode.net>
<4E64D7EA.3010704@ai.wu.ac.at>
<cc2305e664bc05f72ce55eaf7c18db63.squirrel@sq.gransy.com>
hi,
> What does a "normal load" mean? Does that mean a time when the queries are
> slow?
yes, we are have slow queries (according to postgresql.log) with such load
> Are you sure the machine really has 48GB of RAM? Because from the vmstat
> output it seems like there's just 32GB.
>
> procs -----------memory---------- ---swap-- -----io---- -system--
> ----cpu----
> r b swpd free buff cache si so bi bo in cs us sy
> id wa
> 0 0 1342168 336936 107636 31353512 0 0 14 183 1911 3426
> 2 1 93 4
>
>
> 1342168 + 336936 + 107636 + 31353512 = 33140252 ~ 31GB
strange.
we paid for 48G :-) and top and free show 48G
/root# free
total used free shared buffers cached
Mem: 49564860 49310444 254416 0 30908 30329576
-/+ buffers/cache: 18949960 30614900
Swap: 20971512 1370960 19600552
> Otherwise I don't see anything wrong in the output. What is the size of
> the database (use pg_database_size to get it)? Did it grow significantly
> recently?
>
there are a number of databases in the cluster on that machine,
in the filesystem it adds up to 271G
cheers gerhard
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To: pgsql-performance@postgresql.org
Cc: wohlg@ai.wu.ac.at, tv@fuzzy.cz, andy@squeakycode.net, heinz@langatium.net, wohlg@ai.wu-wien.ac.at, albert.weichselbraun@wu.ac.at
Subject: Re: Sudden drop in DBb performance
In-Reply-To: <4E65DA89.2030106@ai.wu.ac.at>
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