From: Richard Yen <richyen@iparadigms.com>
To: Kevin Grittner <Kevin.Grittner@wicourts.gov>
Cc: Robert Haas <robertmhaas@gmail.com>
Cc: Scott Marlowe <scott.marlowe@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: [Slony1-general] WAL partition overloaded--by autovacuum?
Date: Thu, 8 Jul 2010 12:25:01 -0700
Message-ID: <855D47FE-2386-4933-BED3-55FE2BA42CC0@iparadigms.com> (raw)
In-Reply-To: <4C35DADF020000250003326D@gw.wicourts.gov>
References: <03D2C5F0-F222-4088-B5E4-8DA688565B70@iparadigms.com>
<AANLkTik1oR2fMBp9pzpeYUgrANXKpK0B23scXONQEK1z@mail.gmail.com>
<78E79F0B-5C6C-4BDA-B69C-C0FBF69ABBC7@iparadigms.com>
<AANLkTim9s_S0LS3VtjxUVGuGOHkl_2n7YfpB3KWwdlm-@mail.gmail.com>
<4C35DADF020000250003326D@gw.wicourts.gov>
On Jul 8, 2010, at 12:04 PM, Kevin Grittner wrote:
> Robert Haas <robertmhaas@gmail.com> wrote:
>
>> I don't understand how you managed to fill up 37GB of disk with
>> WAL files. Every time you fill up checkpoint_segments * 16MB of
>> WAL files, you ought to get a checkpoint. When it's complete, WAL
>> segments completely written before the start of the checkpoint
>> should be recyclable. Unless I'm confused, which apparently I am.
>
> You're not alone. At first I was assuming that it was because of
> archiving, but the OP says that's turned off. Unless it had been on
> and there wasn't a *restart* after changing the configuration, I
> can't see how this could happen, and was hoping someone else could
> cast some light on the issue.
I'm fairly confused myself. I'm beginning to think that because data/base and data/pg_xlog were on the same partition (/db), when the /db partition filled, up the WAL files couldn't get flushed to data/base, thereby preventing data/pg_xlog from being emptied out, as per the documentation.
My concern is that--as in the original post--there were moments where 129 WAL files were generated in one minute. Is it plausible that this autovacuum could be responsible for this?
--Richard
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To: pgsql-performance@postgresql.org
Cc: richyen@iparadigms.com, Kevin.Grittner@wicourts.gov, robertmhaas@gmail.com, scott.marlowe@gmail.com
Subject: Re: [Slony1-general] WAL partition overloaded--by autovacuum?
In-Reply-To: <855D47FE-2386-4933-BED3-55FE2BA42CC0@iparadigms.com>
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