On 07/06/2014 10:11 AM, Andres Freund wrote:
Hi Steve,
Right. I thought about this for a while, and I think we should change
two things. For one, don't request replies here. It's simply not needed,
as this isn't dealing with timeouts. For another don't just check ->flush
< sentPtr but also && ->write < sentPtr. The reason we're sending these
feedback messages is to inform the 'logical standby' that there's been
WAL activity which it can't see because they don't correspond to
anything that's logically decoded (e.g. vacuum stuff).
Would that suit your needs?
Greetings,
Yes I think that will work for me.
I tested with the attached patch that I think does what you describe
and it seems okay.
Andres Freund
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
new file mode 100644
index 3189793..844a5de
*** a/src/backend/replication/walsender.c
--- b/src/backend/replication/walsender.c
*************** WalSndWaitForWal(XLogRecPtr loc)
*** 1203,1211 ****
* possibly are waiting for a later location. So we send pings
* containing the flush location every now and then.
*/
! if (MyWalSnd->flush < sentPtr && !waiting_for_ping_response)
{
! WalSndKeepalive(true);
waiting_for_ping_response = true;
}
--- 1203,1213 ----
* possibly are waiting for a later location. So we send pings
* containing the flush location every now and then.
*/
! if (MyWalSnd->flush < sentPtr &&
! MyWalSnd->write < sentPtr &&
! !waiting_for_ping_response)
{
! WalSndKeepalive(false);
waiting_for_ping_response = true;
}
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
