On Wed, Oct 16, 2024 at 11:20 PM Alexander Korotkov <aekorotkov@gmail.com> wrote: > > On Wed, Oct 16, 2024 at 10:35 PM Peter Eisentraut <peter@eisentraut.org> wrote: > > On 02.09.24 01:55, Alexander Korotkov wrote: > > > On Mon, Sep 2, 2024 at 2:28 AM Michael Paquier <michael@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.
0001:
Looks completely ok.
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?
0003:
Besides refactor it looks that deleteLSNWaiter() is added in WaitForLSNReplay. Maybe it's worth mentioning in the commit message.
Maybe refactoring for loop for assigning result variable and breaking a loop instead of immediate return would look better and lead to natural call of after the loop before returning.
0004:
Comment:
+ * Waits until recovery replays the target LSN with optional timeout. Throw
+ * an error on failure.
may need mentioning "Unless no_error provided throws an error on failure"
