Re: Allowing multiple concurrent base backups

On Wed, Jan 12, 2011 at 05:17:38PM +0200, Heikki Linnakangas wrote:
> On 12.01.2011 17:15, David Fetter wrote:
> >On Wed, Jan 12, 2011 at 10:26:05AM +0100, marcin mank wrote:
> >>Considering that parallell base backups would be io-bound (or
> >>network-bound), there is little need to actually run them in parallell
> >
> >That's not actually true.  Backups at the moment are CPU-bound, and
> >running them in parallel is one way to make them closer to I/O-bound,
> >which is what they *should* be.
> 
> That's a different kind of "parallel". We're talking about taking
> multiple backups in parallel, each using one process, and you're
> talking about taking one backup using multiple parallel processes or
> threads.

Good point.  The idea that IO/network bandwidth is always saturated by
one backup just isn't true, though.  Take the case of multiple
independent NICs, e.g.

Cheers,
David.
-- 
David Fetter <david@fetter.org> http://fetter.org/
Phone: +1 415 235 3778  AIM: dfetter666  Yahoo!: dfetter
Skype: davidfetter      XMPP: david.fetter@gmail.com
iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics

Remember to vote!
Consider donating to Postgres: http://www.postgresql.org/about/donate