Re: Logical Replication of sequences

Peter Smith <smithpb2250@gmail.com>

From: Peter Smith <smithpb2250@gmail.com>

To: shveta malik <shveta.malik@gmail.com>

Cc: Nisha Moond <nisha.moond412@gmail.com>, vignesh C <vignesh21@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Shlok Kyal <shlok.kyal.oss@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Peter Eisentraut <peter@eisentraut.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Euler Taveira <euler@eulerto.com>, Michael Paquier <michael@paquier.xyz>, "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, "Jonathan S. Katz" <jkatz@postgresql.org>

Date: 2025-05-20T05:43:04Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Doc: Add documentation for sequence synchronization.
- 55cefadde874 19 (unreleased) landed
Remove unused assignment in CREATE PUBLICATION grammar.
- bfb7419b0bbe 19 (unreleased) landed
Add seq_sync_error_count to subscription statistics.
- f6a4c498dcf6 19 (unreleased) landed
Fix few issues in commit 5509055d69.
- 5a4eba558aa7 19 (unreleased) landed
Add sequence synchronization for logical replication.
- 5509055d6956 19 (unreleased) landed
Add worker type argument to logical replication worker functions.
- 3e8e05596a02 19 (unreleased) landed
Introduce "REFRESH SEQUENCES" for subscriptions.
- f0b3573c3aac 19 (unreleased) landed
Refactor logical worker synchronization code into a separate file.
- 41c674d2e31e 19 (unreleased) landed
Standardize use of REFRESH PUBLICATION in code and messages.
- 2436b8c047ff 19 (unreleased) landed
Add "ALL SEQUENCES" support to publications.
- 96b378497346 19 (unreleased) landed
Expose sequence page LSN via pg_get_sequence_data.
- b93172ca59f4 19 (unreleased) landed
Resume conflict-relevant data retention automatically.
- 0d48d393d465 19 (unreleased) cited
Post-commit review fixes for 228c370868.
- 1f7e9ba3ac4e 19 (unreleased) cited
Generate GUC tables from .dat file
- 63599896545c 19 (unreleased) cited

> Test-scenario:
> --Created 250 sequences on both pub and sub.
> --There were 10 sequences mismatched.
> --Sequence replication worked as expected. Logs look better now:
>
> LOG:  Logical replication sequence synchronization for subscription
> "sub1" - total unsynchronized: 250; batch #1 = 100 attempted, 97
> succeeded, 3 mismatched
> LOG:  Logical replication sequence synchronization for subscription
> "sub1" - total unsynchronized: 250; batch #2 = 100 attempted, 95
> succeeded, 5 mismatched
> LOG:  Logical replication sequence synchronization for subscription
> "sub1" - total unsynchronized: 250; batch #3 = 50 attempted, 48
> succeeded, 2 mismatched
>

When there are many batches required, it seems a bit strange to repeat
the same "total unsynchronized" over and over.

Would it be better to show the total number once, and thereafter show
the number of sequences remaining to be processed as they tick down?

e.g.
LOG:  Logical replication sequence synchronization for subscription
"sub1" - total unsynchronized = 250
LOG:  Logical replication sequence synchronization for subscription
"sub1" - batch #1 = 100 attempted, 97 succeeded, 3 mismatched, 150
remaining
LOG:  Logical replication sequence synchronization for subscription
"sub1" - batch #2 = 100 attempted, 95 succeeded, 5 mismatched, 50
remaining
LOG:  Logical replication sequence synchronization for subscription
"sub1" - batch #3 = 50 attempted, 48 succeeded, 2 mismatched, 0
remaining

======
Kind Regards,
Peter Smith.
Fujitsu Australia