Re: New standby_slot_names GUC in PG 17

Bertrand Drouvot <bertranddrouvot.pg@gmail.com>

From: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
To: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Muhammad Ikram <mmikram@gmail.com>, Bruce Momjian <bruce@momjian.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Nathan Bossart <nathandbossart@gmail.com>
Date: 2024-06-26T04:49:16Z
Lists: pgsql-hackers
Hi,

On Wed, Jun 26, 2024 at 04:17:45AM +0000, Zhijie Hou (Fujitsu) wrote:
> On Wednesday, June 26, 2024 9:40 AM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> > 
> > On Tue, Jun 25, 2024 at 5:32 PM Amit Kapila <amit.kapila16@gmail.com>
> > wrote:
> > >
> > > I feel synchronized better indicates the purpose because we ensure
> > > such slots are synchronized before we process changes for logical
> > > failover slots. We already have a 'failover' option for logical slots
> > > which could make things confusing if we add 'failover' where physical
> > > slots need to be specified.
> > 
> > Agreed. So +1 for synchronized_stnadby_slots.
> 
> +1.
> 
> Since there is a consensus on this name, I am attaching the patch to rename
> the GUC to synchronized_stnadby_slots. I have confirmed that the regression
> tests and pgindent passed for the patch.
> 

Thanks for the patch!

A few comments:

1 ====

In the commit message:

"
The standby_slot_names GUC is intended to allow specification of physical
    standby slots that must be synchronized before they are visible to
    subscribers
"

Not sure that wording is correct, if we feel the need to explain the GUC,
maybe repeat some wording from bf279ddd1c?

2 ====

Should we rename StandbySlotNamesConfigData too?

3 ====

Should we rename SlotExistsInStandbySlotNames too?

4 ====

Should we rename validate_standby_slots() too?

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com



Commits

  1. Update release notes to reflect recent commit 0f934b0739.

  2. Rename standby_slot_names to synchronized_standby_slots.

  3. Add a new slot sync worker to synchronize logical slots.