Hi, Alexander! On Wed, 23 Oct 2024 at 00:12, Alexander Korotkov <aekorot...@gmail.com> wrote:
> Hi, Pavel! > > Thank you for your review. > > On Tue, Oct 22, 2024 at 4:30 PM Pavel Borisov <pashkin.e...@gmail.com> > wrote: > > On Tue, 22 Oct 2024 at 13:26, Alexander Korotkov <aekorot...@gmail.com> > wrote: > >> > >> On Wed, Oct 16, 2024 at 11:20 PM Alexander Korotkov > >> <aekorot...@gmail.com> wrote: > >> > > >> > On Wed, Oct 16, 2024 at 10:35 PM Peter Eisentraut < > pe...@eisentraut.org> wrote: > >> > > On 02.09.24 01:55, Alexander Korotkov wrote: > >> > > > On Mon, Sep 2, 2024 at 2:28 AM Michael Paquier < > mich...@paquier.xyz> wrote: > >> > > >> On Sun, Sep 01, 2024 at 10:35:27PM +0300, Alexander Korotkov > wrote: > >> > > >>> This path hasn't changes since the patch revision when it was a > >> > > >>> utility command. I agree that this doesn't look like proper > path for > >> > > >>> stored procedure. But I don't think src/backend/utils/adt is > >> > > >>> appropriate path either, because it's not really about data > type. > >> > > >>> pg_wal_replay_wait() looks a good neighbor for > >> > > >>> pg_wal_replay_pause()/pg_wal_replay_resume() and other > WAL-related > >> > > >>> functions. So, what about moving it to > src/backend/access/transam? > >> > > >> > >> > > >> Moving the new function to xlogfuncs.c while publishing > >> > > >> WaitForLSNReplay() makes sense to me. > >> > > > > >> > > > Thank you for proposal. I like this. > >> > > > > >> > > > Could you, please, check the attached patch? > >> > > > >> > > We still have stuff in src/backend/commands/waitlsn.c that is > nothing > >> > > like a "command". You have moved some stuff elsewhere, but what > are you > >> > > planning to do with the rest? > >> > > >> > Thank you for spotting this another time. What about moving that > >> > somewhere like src/backend/access/transam/xlogwait.c ? > >> > >> Implemented this as a separate patch (0001). Also rebased other > >> pending patches on that. 0004 now revises header comment of > >> xlogwait.c with new procedure signature. > > > > > > I've looked at v5 of a patchset. > > > 0002: > > > > As stated in latch.c > > > > - WL_POSTMASTER_DEATH: Wait for postmaster to die > > - WL_EXIT_ON_PM_DEATH: Exit immediately if the postmaster dies > > > > * wakeEvents must include either WL_EXIT_ON_PM_DEATH for automatic exit > > * if the postmaster dies or WL_POSTMASTER_DEATH for a flag set in the > > * return value if the postmaster dies > > > > It's not completely clear to me if these comments need some > clarification (not related to the patchset), or if we should look for > WL_EXIT_ON_PM_DEATH for immediately FATAL. Or waiting for postmaster to die > on WL_POSTMASTER_DEATH instead of just fatal immediately? > > As I get from the code, WL_EXIT_ON_PM_DEATH cause process to just > proc_exit(1) without throwing FATAL. So, in the most of situations we > do throw FATAL after seeing WL_POSTMASTER_DEATH event. So, it's > reasonable to do the same here. But indeed, this is a question (not > related to this patch) whether WL_EXIT_ON_PM_DEATH should cause > process to throw FATAL. > Libpq ends up with FATAL on WL_POSTMASTER_DEATH. In a backend code on WL_POSTMASTER_DEATH: SyncRepWaitForLSN() sets ProcDiePending but don't FATAL. Walsender exits proc_exit(1). I suppose WL_POSTMASTER_DEATH expected behavior is "Do whatever you want: wait for postmaster to die or end up immediately". I think path 0002 is good. I looked through patches v6 and I think they're all good now. Regards, Pavel Borisov Supabase.
