Re: Separate GUC for replication origins

Masahiko Sawada <sawada.mshk@gmail.com>

From: Masahiko Sawada <sawada.mshk@gmail.com>
To: Euler Taveira <euler@eulerto.com>
Cc: vignesh C <vignesh21@gmail.com>, Peter Eisentraut <peter@eisentraut.org>, Amit Kapila <amit.kapila16@gmail.com>, pgsql-hackers@lists.postgresql.org
Date: 2025-03-17T23:44:26Z
Lists: pgsql-hackers
On Thu, Mar 13, 2025 at 5:55 PM Euler Taveira <euler@eulerto.com> wrote:
>
> On Thu, Mar 13, 2025, at 11:10 AM, vignesh C wrote:
>
> Few comments:
>
>
> Thanks for taking a look.
>
> 1) After selecting max_active_replication_origins setting in the
> SELECT query having order by, the first record returned will be the
> one with max_active_replication_origins, rather than the second
> record, because max_active_replication_origins appears before
> max_logical_replication_workers in the order.
>
>
> Fixed.
>
> 2) I felt max_replication_slots must be max_active_replication_origins
> here in logical-replication.sgml:
>
>
> Fixed.

Thank you for updating the patch. I have one comment:

 #max_logical_replication_workers = 4   # taken from max_worker_processes
                    # (change requires restart)
+#max_active_replication_origins = 10   # maximum number of active
replication origins
+                   # (change requires restart)
 #max_sync_workers_per_subscription = 2 # taken from
max_logical_replication_workers
 #max_parallel_apply_workers_per_subscription = 2   # taken from
max_logical_replication_workers

I would suggest putting the new max_active_replication_origins after
max_parallel_apply_workers_per_subscription as both
max_sync_workers_per_subscription and
max_parallel_apply_workers_per_subscription are related to
max_logical_replication_workers.

The rest looks good to me.

Regards,

-- 
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com



Commits

  1. Add GUC option to control maximum active replication origins.

  2. Better document logical replication parameters

  3. Introduce replication progress tracking infrastructure.