Re: Hot Standby query cancellation and Streaming Replication integration

> The part I still don't have good visibility on is how much of the
> necessary SR infrastructure needed to support this communications
> channel is already available in some form.  I had though the walsender
> on the master was already receiving messages sometimes from the
> walreceiver on the standby, but I'm getting the impression from Heikki's
> comments that this not the case at all yet.

I don't think asking for a 2nd connection back from the standby to the
master would be horrible for 9.0.  I think it would be quite reasonable,
actually; even with 2 connections per slave, you could still have quite
a few slaves before the # of connections bogged down the master.

--Josh