Re: Proposal: recent access based routing for primary-replica setups

Hi Tatsuo,

Sorry for the late reply - I'm traveling with my family at the moment (in
Japan actually) and might be delayed in responding.

Re your points:
1 - we can, but I have to say that a user I tend to prefer configuration
values not have a "magic" value that does something different than the
usual case like this would create. I'd stick with what we already have
planned. happy to hear from others on the mailing list as well of course.

2 - I think we can have the primary always be the first or we can
completely remove it since it might be redundant as it's always going to be
0. what do you think?

3 - I agree with you, next version (after we clear everything else) will
have only ip/hostname+port.

Let me know your thoughts

Thanks!

On Tue, Sep 9, 2025 at 9:42 AM Tatsuo Ishii <ishii(at)postgresql(dot)org> wrote:

> Hi Nadav,
>
> > Hi Tatsuo,
> >
> > Please find attached the 3 patch files (implementation, tests, docs) with
> > the updates we discussed.
> >
> > What do you think?
>
> I haven't read the code details yet but I have a few questions.
>
> 1) Can we use only replication_delay_source_cmd and if it's value is
> 'builtin', then we treat it as replication_delay_source = builtin?
> Maybe this is matter of taste but I would like to know your
> opinion.
>
> 2) replication_delay_source_cmd will be given an ordered list of
> instance identifiers. But it seems there's no way for the command
> which one is the primary instance. Is it okay for the command?
>
> 3) Why do you have 3 kind of instance identifiers (application name,
> hostname (IP) + port and node id? I thought "hostname (IP) + port"
> is sufficient.
>
> Comments?
> --
> Tatsuo Ishii
> SRA OSS K.K.
> English: http://www.sraoss.co.jp/index_en/
> Japanese:http://www.sraoss.co.jp
>

--
Nadav Shatz
Tailor Brands | CTO