On Mon, Feb 6, 2023 at 10:33 AM Andres Freund <and...@anarazel.de> wrote: > > On February 5, 2023 8:29:19 PM PST, Amit Kapila <amit.kapil...@gmail.com> > wrote: > >> > >> But that seems a too narrow view to me. Imagine you want to decomission > >> the current primary, and instead start to use the logical standby as the > >> primary. For that you'd obviously want to replicate the last few > >> changes. But with the proposed change, that'd be hard to ever achieve. > >> > > > >I think that can still be achieved with the idea being discussed which > >is to keep allowing sending the WAL for smart shutdown mode but not > >for other modes(fast, immediate). I don't know whether it is a good > >idea or not but Kuroda-San has produced a POC patch for it. We can > >instead choose to improve our docs related to shutdown to explain a > >bit more about the shutdown's interaction with (logical and physical) > >replication. As of now, it says: (“Smart” mode disallows new > >connections, then waits for all existing clients to disconnect. If the > >server is in hot standby, recovery and streaming replication will be > >terminated once all clients have disconnected.)[2]. Here, it is not > >clear that shutdown will wait for sending and flushing all the WALs. > >The information for fast and immediate modes is even lesser which > >makes it more difficult to understand what kind of behavior is > >expected in those modes. > > > >[1] - https://commitfest.postgresql.org/42/3581/ > >[2] - https://www.postgresql.org/docs/devel/app-pg-ctl.html > > > > Smart shutdown is practically unusable. I don't think it makes sense to tie > behavior of walsender to it in any way. >
So, we have the following options: (a) do nothing for this; (b) clarify the current behavior in docs. Any suggestions? -- With Regards, Amit Kapila.
