On Tue, 2010-04-06 at 10:19 +0300, Heikki Linnakangas wrote:
> Fujii Masao wrote:
> > On Tue, Apr 6, 2010 at 3:29 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> >> I was also surprised to note that the Startup process is not signaled by
> >> WALReceiver when new WAL is received, so it will continue sleeping even
> >> though it has work to do.
> >
> > I don't think this is so useful in 9.0 since synchronous replication
> > (i.e., transaction commit wait for WAL to be replayed by the standby)
> > is not supported.
>
> Well, it would still be useful, as it would shorten the delay. But yeah,
> there's a delay in asynchronous replication anyway, so we decided to
> keep it simple and just poll. It's not ideal and definitely needs to be
> revisited for synchronous mode in the future. Same for walsenders.
A signal seems fairly straightforward to me, the archiver did this in
8.0 and it was not considered complex then. Quite why it would be
complex here is not clear.
I'm not happy that it waits, nor that the wait is non-tunable. I would
like to see a new parameter added for this.
-- Simon Riggs www.2ndQuadrant.com