Re: Synchronizing slots from primary to standby

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>
To: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Cc: Peter Smith <smithpb2250@gmail.com>, "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, shveta malik <shveta.malik@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Ajin Cherian <itsajin@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Nisha Moond <nisha.moond412@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Bruce Momjian <bruce@momjian.us>, Ashutosh Sharma <ashu.coek88@gmail.com>, Andres Freund <andres@anarazel.de>, pgsql-hackers <pgsql-hackers@postgresql.org>, Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: 2024-03-05T03:24:50Z
Lists: pgsql-hackers
On Mon, Mar 4, 2024 at 2:27 PM Bertrand Drouvot
<bertranddrouvot.pg@gmail.com> wrote:
>
> On Thu, Feb 29, 2024 at 03:38:59PM +0530, Amit Kapila wrote:
> > On Thu, Feb 29, 2024 at 9:13 AM Peter Smith <smithpb2250@gmail.com> wrote:
> > >
> > > On Tue, Feb 27, 2024 at 11:35 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> > > >
> > >
> > > > Also, adding wait sounds
> > > > more like a boolean. So, I don't see the proposed names any better
> > > > than the current one.
> > > >
> > >
> > > Anyway, the point is that the current GUC name 'standby_slot_names' is
> > > not ideal IMO because it doesn't have enough meaning by itself -- e.g.
> > > you have to read the accompanying comment or documentation to have any
> > > idea of its purpose.
> > >
> >
> > Yeah, one has to read the description but that is true for other
> > parameters like "temp_tablespaces". I don't have any better ideas but
> > open to suggestions.
>
> What about "non_lagging_standby_slots"?
>

I still prefer the current one as that at least resembles with
existing synchronous_standby_names. I think we can change the GUC name
if we get an agreement on a better name before release. At this stage,
let's move with the current one.

-- 
With Regards,
Amit Kapila.



Commits

  1. Doc: Add the new section "Logical Replication Failover".

  2. Fix the review comments and a bug in the slot sync code.

  3. Fix a test in failover slots regression test.

  4. Fix the intermittent buildfarm failures in 040_standby_failover_slots_sync.

  5. Split XLogCtl->LogwrtResult into separate struct members

  6. Ensure that the sync slots reach a consistent state after promotion without losing data.

  7. Introduce a new GUC 'standby_slot_names'.

  8. Fix BF failure introduced by commit b3f6b14cf4.

  9. Fixups for commit 93db6cbda0.

  10. Fix BF failure in commit 93db6cbda0.

  11. Add a new slot sync worker to synchronize logical slots.

  12. Improve ERROR/LOG messages added by commits ddd5f4f54a and 7a424ece48.

  13. Disable autovacuum on primary in 040_standby_failover_slots_sync test.

  14. Fix the incorrect format specifier used in commit 7a424ece48.

  15. Change the LOG level in 040_standby_failover_slots_sync.pl to DEBUG2.

  16. Add more LOG and DEBUG messages for slot synchronization.

  17. Another try to fix BF failure introduced in commit ddd5f4f54a.

  18. Fix BF introduced in commit ddd5f4f54a.

  19. Add a slot synchronization function.

  20. Clean-ups for 776621a5e4 and 7329240437.

  21. Enhance libpqrcv APIs to support slot synchronization.

  22. Add a failover option to subscriptions.

  23. Allow setting failover property in the replication command.

  24. Allow to enable failover property for replication slots via SQL API.

  25. Add macros for looping through a List without a ListCell.

  26. Track conflict_reason in pg_replication_slots.

  27. Allow upgrades to preserve the full subscription's state.

  28. Add support for incremental backup.

  29. Simplify some logic in CreateReplicationSlot()

  30. Fix uninitialized access to InitialRunningXacts during decoding after ERROR.

  31. Flexible options for CREATE_REPLICATION_SLOT.

  32. Empty search_path in logical replication apply worker and walsender.

  33. Fix oldest xmin and LSN computation across repslots after advancing

  34. Require C99 (and thus MSCV 2013 upwards).