Re: excessive WAL activity

bricklen wrote:
> 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?

Also, it might be good to check how much is really going on.
Try log_statement=all and see how much gets logged.

Yours,
Laurenz Albe