[rt-users] Excessive communication between RT and postgresql

[Alex Vandiver]

On Mon, 2013-12-16 at 13:58 +0000, Jacobsson, Henrik G wrote:
> After upgrading to RT 4.2.1, the postgresql database is producing
> massive volumes of WAL files around the clock with peaks during office
> hours.

And what version were you upgrading from?

> Before the upgrade – we had very limited volumes of WAL files
> produced, and nothing at all during non work hours. Now – at least
> 32MB, but usually 64MB of WAL is written every minute, when the system
> is supposed to be quiet.

Does that output cease if you temporarily turn off the webserver?  What
about if you disable your incoming MTA?

> Should there be any traffic at all between the RT server and database
> server when the system is not in use? Apart from occasional handshakes
> etc.

Depends what you mean by "in use."  RT has no long-running programs
aside from the web front-end; as such, requests to the database are only
generated by requests to Apache, or the cron jobs.  At times when there
are no Apache requests and no cron jobs, there should be no significant
database traffic.

Bear in mind that even if no _users_ are accessing the website, incoming
email gets POST'ed to the mail gateway endpoint, which may account for
some of the activity when you believe the system is not in use.

It may be enlightening to examine the generated WAL logs using
http://www.postgresql.org/docs/current/static/pgxlogdump.html
 - Alex