Обсуждение: [ADMIN] Question about pg_xlog

M Kiesewetter <mskiesewetter@gmail.com> writes:

> Hi everyone,
>
> I'm new to Postgresql and have a test environment with Postgresql
> 9.4.5 running on Linux.
> Today I noticed that the pg_xlog was filled up to 18 Gb.
> I have: 
> - wal_level=hot_standby 
> - wal_keep_segments = 100
> - hot_standby = on
> archive_mode = on
>
> It's a test environment en I did a pg_resetxlogs() on the 6th of
> April.
> I know that I shouldn't use this, and that it's only a last resort.
> When I look in de pg_xlog directory I see xlog files that are kept
> sinds that time.
> When i look at the archive_status directory I see that all of the
> files have the suffix of .done.
> All the other xlogs from the time before the resetlogs are cleaned up
> as I expected.
> But I don't understand why the other xlogs aren't recycled.

I'd start by looking for dormant replication slots.

select * from pg_replication_slots;

HTH

> I am looking for ways to find out why my pg_xlog is filling up.
> - I checked the alertlog of the postgresql instance --> no errors
> - I checked the WAL file location to see if the xlogs are being
> archived --> they are present
>
> Are there more ways to find out why my pg_xlog is filling up?
> Is the pg_resetxlogs the reason why the older xlogs are not recycled?
>
> I Hope that someone can help me.
> Thanks in advance.
> Regards,
> Mariane
>
>
>

--
Jerry Sievers
e: jerry.sievers@comcast.net
p: 312.241.7800

Jerry Sievers wrote:
> M Kiesewetter <mskiesewetter@gmail.com> writes:
> > I'm new to Postgresql and have a test environment with Postgresql
> > 9.4.5 running on Linux.
> > Today I noticed that the pg_xlog was filled up to 18 Gb.
> > I have:
> > - wal_level=hot_standby
> > - wal_keep_segments = 100
> > - hot_standby = on
> > archive_mode = on
> >
> > It's a test environment en I did a pg_resetxlogs() on the 6th of
> > April.
> > I know that I shouldn't use this, and that it's only a last resort.
> > When I look in de pg_xlog directory I see xlog files that are kept
> > sinds that time.
> > When i look at the archive_status directory I see that all of the
> > files have the suffix of .done.
> > All the other xlogs from the time before the resetlogs are cleaned up
> > as I expected.
> > But I don't understand why the other xlogs aren't recycled.
> 
> I'd start by looking for dormant replication slots.
> 
> select * from pg_replication_slots;

Don't forget to check pg_prepared_xacts if there are any prepared
transactions that have not been committed or rolled back.

Also, if archive_mode is on, check if archive_command might have
had a non-zero return code.  You should find messages in the PostgreSQL log.

Yours,
Laurenz Albe