Re: High CPU load caused by the autovacuum launcher process

On Fri, Jun 8, 2018 at 3:24 AM, Owayss Kabtoul <owayssk(at)gmail(dot)com> wrote:

> Hi folks,
>
> I ran into an issue where, on Postgres instances that have a very large
> number of databases per cluster (~15K), the autovacuum process seems to
> have a very high impact on CPU usage. Specifically, it is the autovacuum
> launcher process, not the workers. The launcher process eats a whole CPU
> (attached is in screenshot of htop).
> ...
> So auto-vacuum never really sleeps. Even changing the autovacuum_naptime
> and setting it to a much higher value (from 1min to 50min) did not have any
> effect at all.
>

After changing autovacuum_naptime, did you give it enough time to stabilize
at the new setting? Say, at least 3 * 50 = 150 minutes?

But overall, I would say that if you want to have 15,000 databases, you
should just resign yourself to having one CPU dedicated to this task.

Cheers,

Jeff