Horton

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

Hayato Kuroda (Fujitsu) <kuroda.hayato@fujitsu.com>

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From: "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>
To: 'Bharath Rupireddy' <bharath.rupireddyforpostgres@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.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: 2023-09-23T04:49:43Z
Lists: pgsql-hackers 
Dear Bharath,

> > You mentioned at line 118, but at that time logical replication system is not
> created.
> > The subscriber is created at line 163.
> > Therefore WALs would not be consumed automatically.
> 
> So, not calling pg_logical_slot_get_changes() on test_slot1 won't
> consume the WAL?

Yes. This slot was created manually and no one activated it automatically.
pg_logical_slot_get_changes() can consume WALs but never called.

> 
> 2.
> +++ b/src/bin/pg_upgrade/t/003_logical_replication_slots.pl
> 
> How about a more descriptive and pointed name for the TAP test file,
> something like 003_upgrade_logical_replication_slots.pl?

Good suggestion. Renamed.

> 3. Does this patch support upgrading of logical replication slots on a
> streaming standby? If yes, isn't it a good idea to add one test for
> upgrading standby with logical replication slots?

IIUC pg_upgrade would not be used for physical standby. The standby would be upgrade by:

* Recreating the database cluster, or
* Executing rsync command.

For more detail, please see the documentation.

Best Regards,
Hayato Kuroda
FUJITSU LIMITED

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.