Re: Weird WAL problem - 9.0.3 - Mailing list pgsql-general

From Adrian Klaver
Subject Re: Weird WAL problem - 9.0.3
Date
Msg-id 201104130628.35321.adrian.klaver@gmail.com
Whole thread Raw
In response to Weird WAL problem - 9.0.3  (Rafael Martinez <r.m.guerrero@usit.uio.no>)
Responses Re: Weird WAL problem - 9.0.3
List pgsql-general

On Wednesday, April 13, 2011 6:09:25 am Rafael Martinez wrote:

> Hello

>

> Yesterday we had a weird problem with the pg_xlog partition in one of

> our servers:

>

> - The amount of WAL files was much higher than (2*checkpoint_segments)+1

> (over 360 WAL files)

>

Might want to take a look at:

http://www.postgresql.org/docs/9.0/interactive/wal-configuration.html

In particular:

"There will always be at least one WAL segment file, and will normally not be more files than the higher of wal_keep_segments or (2 + checkpoint_completion_target) * checkpoint_segments + 1. Each segment file is normally 16 MB (though this size can be altered when building the server). You can use this to estimate space requirements for WAL. Ordinarily, when old log segment files are no longer needed, they are recycled (renamed to become the next segments in the numbered sequence). If, due to a short-term peak of log output rate, there are more than 3 * checkpoint_segments + 1 segment files, the unneeded segment files will be deleted instead of recycled until the system gets back under this limit."

--

Adrian Klaver

adrian.klaver@gmail.com

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