Re: How should the primary behave when the sync standby goes away? Re: Sync Rep v17

On Mon, 2011-03-07 at 13:15 -0500, Robert Haas wrote:
> On Sun, Mar 6, 2011 at 5:36 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> > On Fri, 2011-03-04 at 16:57 +0900, Fujii Masao wrote:
> >> On Wed, Mar 2, 2011 at 11:30 PM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> >> > On Wed, Mar 2, 2011 at 8:22 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:

> >>
> >> Also I think that the waiting backends should be released as soon as the
> >> last synchronous standby switches to asynchronous mode. Since there is
> >> no standby which is planning to reconnect, obviously they no longer need
> >> to wait.
> >
> > I've not done this, but we could.
> >
> > It can't run in a WALSender, so this code would need to live in either
> > WALWriter or BgWriter.
>
> I would have thought that the last WALSender to switch to async would
> have been responsible for doing this at that time. Why doesn't that
> work?

The main time we get extended waits is when there are no WALsenders.

--
Simon Riggs http://www.2ndQuadrant.com/books/
PostgreSQL Development, 24x7 Support, Training and Services