Re: excessive WAL activity

On Wed, Jun 19, 2013 at 4:22 PM, Sean Dillon <sean(at)dillonsoftware(dot)com>wrote:

> Just turned on WAL archiving to an S3 bucket for a small database - total
> size of perhaps 2-4G. After turning on achiving, we're seeing WAL logs
> written to S3 at the rate of about 1G every 3 minutes. That seems
> completely unreasonable given usage of the db. I can even see that nearly
> nothing is happening with this:
>
> select datname, usename, procpid, client_addr, waiting, query_start,
> current_query from pg_stat_activity;
>
> Nearly every time I run that, all 20 connections have current_query =
> '<IDLE>'. Does current_query include inserts, updates, and deletes or just
> select statements?
>
> Any ideas what to look for or how to solve this?
>

Can you show the results from:

SELECT name, current_setting(name), source
FROM pg_settings
WHERE source NOT IN ('default', 'override')
UNION ALL
SELECT 'version' as name, version(), null;

Perhaps there is a setting there (like archive_timeout) which could lead to
an answer. In your $PGDATA/pg_xlog directory, look at the timestamps of the
WAL segments, are there lots of files generated per minute?