Re: Defaults for replication/backup

On Sat, Feb 13, 2016 at 2:39 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:

> On 2016-02-13 22:37:33 +0900, Michael Paquier wrote:
> > On Sat, Feb 13, 2016 at 10:15 PM, Magnus Hagander wrote:
> > > So, I suggest the following changes to the defaults:
> > > wal_level=hot_standby
> > > max_wal_senders=10
> > > max_replication_slots=10
>
> +1. I'm inclined to set slots a bit higher than senders. They're pretty
> cheap...
>

So something like 10/20?

> I think this is way past due.
>
> > 10 seems a bit high. I would think that max_wal_senders and
> > max_replication_slots set at 3 are sufficient enough, giving enough
> > room for simple deployments willing to use replication.
>
> But they're relatively cheap to enable, so why set them low?
>
>
That's my reasoning as well. I think you will be hard pressed to even
measure the overhead between 3 and 10. The big difference will be in
leaving 0 and in particular setting wal_level.

--
Magnus Hagander
Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/