Re: autovacuum launcher eating too much CPU

On Thursday 13 September 2007 09:16:52 Alvaro Herrera wrote:
> Hi,
>
> Darcy Buskermolen noticed that when one has many databases, the autovac
> launcher starts eating too much CPU.

Don't forget the memory leak as well. after 3 or 4 days of running I end up
with a 2GB+ AVL..

>
> I tried it here with 200 databases and indeed it does seem to eat its
> share. Even with the default naptime, which I wouldn't have thought
> that was too high (it does make the launcher wake up about three times a
> second though).
>
> I'm looking at a profile and I can't seem to make much sense out of it.
> It seems to me like the problem is not autovac itself, but rather the
> pgstat code that reads the stat file from disk. Of course, autovac does
> need to read the file fairly regularly.
>
> Here is the top lines of gprof output.
>
> Comments? Is there something here that needs fixing?
--

Darcy Buskermolen
The PostgreSQL company, Command Prompt Inc.
http://www.commandprompt.com/