Horton

Re: [PoC] pg_upgrade: allow to upgrade publisher node

Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>

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From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Amit Kapila <amit.kapila16@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, Dilip Kumar <dilipbalaut@gmail.com>, "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, Peter Smith <smithpb2250@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Bruce Momjian <bruce@momjian.us>, Julien Rouhaud <rjuju123@gmail.com>, vignesh C <vignesh21@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>
Date: 2023-09-28T08:52:21Z
Lists: pgsql-hackers 
On Fri, Sep 22, 2023 at 9:40 AM Michael Paquier <michael@paquier.xyz> wrote:
>
> On Thu, Sep 21, 2023 at 01:50:28PM +0530, Amit Kapila wrote:
> > We have discussed this point. Normally, we don't have such options in
> > upgrade, so we were hesitent to add a new one for this but there is a
> > discussion to add an --exclude-logical-slots option. We are planning
> > to add that as a separate patch after getting some more consensus on
> > it. Right now, the idea is to get the main patch ready.
>
> Okay.  I am wondering if the subscriber part is OK now without an
> option, but that could also be considered separately, as well.  At
> least I hope so.

+1 for an option to skip upgrade logical replication slots for the
following reasons:
- one may not want the logical replication slots on the upgraded
instance immediately - unless the upgraded instance is tested and
determined to be performant.
- one may not want the logical replication slots on the upgraded
instance immediately - no logical replication setup is wanted on the
new instance perhaps because of an architectural/organizational
decision.
- one may take backup of the postgres instance with logical
replication slots using any of the file system/snapshot based backup
mechanisms (not pg_basebackup), essentially getting the on-disk
replication slots data as well; the pg_upgrade may fail on the
backed-up instance.

I agree to have it as a 0002 patch once the design and things are
finalized for the main patch.

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com

Commits

  1. Fix issues in binary_upgrade_logical_slot_has_caught_up().

  2. Fix a random failure in 003_logical_slots.pl.

  3. Fix a test in 003_logical_slots.

  4. Fix uninitialized slot array access during the upgrade.

  5. Fix the test 003_logical_slots.

  6. Commit b195e6d482 forgot to update meson.build.

  7. Use shorter file names in the upgrade logical slots test.

  8. Migrate logical slots to the new node during an upgrade.

  9. Flush logical slots to disk during a shutdown checkpoint if required.

  10. Prevent possibility of panics during shutdown checkpoint.