Re: Repeated requests for feedback in logical standby

On 12 April 2016 at 16:18, Magnus Hagander <magnus(at)hagander(dot)net> wrote:
>
> I've been running some tests, and come across a weird behavior on shutdown with logical replication, 9.5.2. It seems that on shutdown, a lot of extra requests for feedback are sent from the walsender.
>
> On my laptop I get about 3-15 requests (different each time), and on a server with a bit more power but still very low activity, the number is simply huge.
>
> Basically what happens is:
>
> * Replication works fine
> * I have *zero* activity on the master since it got started, not even a single psql
> * I issue a fast shutdown on the master
> * Nothing happens at all for a while
> * Once pg_recvlogical times out and sends a status message things wake up
> * The server sends a whole bunch of requests for status, which pg_recvlogical responds to
> * Eventually things shut down (on the proper server, I've had to kill things because it takes too long - I'm unsure if it ever shuts down)

That sounds similar to something I've seen with wal-based replication:
http://www.postgresql.org/message-id/flat/CAFgz3kus=rC_avEgBV=+hRK5HYJ8vXskJRh8yEAbahJGTzF2VQ(at)mail(dot)gmail(dot)com#CAFgz3kus=rC_avEgBV=+hRK5HYJ8vXskJRh8yEAbahJGTzF2VQ@mail.gmail.com

Nick