Re: Backup throttling

On Tue, Aug 20, 2013 at 2:37 AM, Heikki Linnakangas
<hlinnakangas@vmware.com> wrote:
> Throttling in the client seems much better to me. TCP is designed to handle
> a slow client.

Other people have already offered some good points in this area, but
let me just add one thought that I don't think has been mentioned yet.
 We have a *general* need to be able to throttle server-side resource
utilization, particularly I/O.  This is a problem not only for
pg_basebackup, but for COPY, CLUSTER, VACUUM, and even things like
UPDATE.  Of all of those, the only one for which we currently have any
kind of a solution is VACUUM.  Now, maybe pg_basebackup also needs its
own special-purpose solution, but I think we'd do well to consider a
general I/O rate-limiting strategy and then consider particular needs
in the light of that framework.  In that context, server-side seems
better to me, because something like CLUSTER isn't going to produce
anything that the client can effectively limit.