Re: wal files stay in the pg_xlog dir

On 08/28/2015 01:59 PM, kingl wrote:
> Hi Adrian
>
> Thank you for your prompt reply.

For more in depth information take a look here:

http://www.postgresql.org/docs/9.4/interactive/wal-configuration.html

which deals with the WAL configuration settings and explains what you
are seeing. To get up to speed on WAL in general start here:

http://www.postgresql.org/docs/9.4/interactive/wal.html

For


>
> In the pg_xlog there are 2,015 wal files now. repmgr recommends to keep 5000
> wal files however for our env that would be an overkill so i changed it to
> 2000.

That looks about right.  The wal_keep_segments = 2000  is a nomimal
number subject to the configuration settings explained in above link.
Monitor this number for a period it should stay in the neighborhood of 2000.

>
> the other issue is that the standby node has only 1345 wal files in the
> pg_xlog, i thought that both nodes' pg_xlog should be exact the same?

The links above go into the full explanation. The short version is that
WAL files are generally meant to be recycled. On the master you are
overriding the recycling to a degree by using wal_keep_segments to force
Postgres to keep at least 2000 files whether they can be recycled or
not. The standby does not have that restriction so it is recycling the
files more aggressively.

>
> thank you again.
>
>
>
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> Sent from the PostgreSQL - general mailing list archive at Nabble.com.
>
>


--
Adrian Klaver
adrian.klaver@aklaver.com