Horton

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

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Cc: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, Dilip Kumar <dilipbalaut@gmail.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: 2023-09-29T10:59:19Z
Lists: pgsql-hackers 
On Fri, Sep 29, 2023 at 1:00 PM Bharath Rupireddy
<bharath.rupireddyforpostgres@gmail.com> wrote:
>
> On Thu, Sep 28, 2023 at 6:08 PM Zhijie Hou (Fujitsu)
> <houzj.fnst@fujitsu.com> wrote:
>
> IMO, WAL scanning approach looks better. However, if were to optimize
> it by not scanning WAL records for every replication slot
> confirmed_flush_lsn (CFL), start with lowest CFL (min of all slots
> CFL), and scan till the end of WAL.
>

Earlier, I also thought something like that but I guess it won't
matter much as most of the slots will be up-to-date at shutdown time.
That would mean we would read just one or two records. Personally, I
feel it is better to build consensus on the WAL scanning approach,
basically, is it okay to decide as the patch is currently doing or
whether we should expose an API from the decode module as you are
proposing? OTOH, if we want to go with other approach like adding
field in pg_controldata then we don't need to deal with WAL record
types at all.

-- 
With Regards,
Amit Kapila.

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.