Horton

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

Julien Rouhaud <rjuju123@gmail.com>

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From: Julien Rouhaud <rjuju123@gmail.com>
To: "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>
Cc: 'vignesh C' <vignesh21@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Amit Kapila <amit.kapila16@gmail.com>
Date: 2023-04-20T06:53:59Z
Lists: pgsql-hackers 
Hi,

On Thu, Apr 20, 2023 at 05:31:16AM +0000, Hayato Kuroda (Fujitsu) wrote:
> Dear Vignesh,
>
> Thank you for reviewing! PSA new patchset.
>
> > > Additionally, I added a checking functions in 0003
> > > According to pg_resetwal and other functions, the length of
> > CHECKPOINT_SHUTDOWN
> > > record seems (SizeOfXLogRecord + SizeOfXLogRecordDataHeaderShort +
> > sizeof(CheckPoint)).
> > > Therefore, the function ensures that the difference between current insert
> > position
> > > and confirmed_flush_lsn is less than (above + page header).

I think that this test should be different when just checking for the
prerequirements (live_check / --check) compared to actually doing the upgrade,
as it's almost guaranteed that the slots won't have sent everything when the
source server is up and running.

Maybe simply check that all logical slots are currently active when running the
live check, so at least there's a good chance that they will still be at
shutdown, and will therefore send all the data to the subscribers?  Having a
regression tests for that scenario would also be a good idea.  Having an
uncommitted write transaction should be enough to cover it.

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.