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

I would actually suggest including down state instances in case pgpool
isn’t aware yet. It can exclude them once it does.
For these cases maybe -1 ?

Nadav Shatz
Tailor Brands | CTO

On Mon, Sep 22, 2025 at 7:34 AM Tatsuo Ishii <ishii(at)postgresql(dot)org> wrote:

> > Thank you for the kind words. We are having a great time!
>
> Glad to hear that!
>
> > Regarding the command knowing about the primary I think it is safe to
> assume.
>
> Okay.
>
> > We can start this way and evolve in the future if needed.
>
> Agreed.
>
> > I can include a note about it in the notes that the command will only
> receive the secondary instances as arguments.
> >
> > Anything else that comes to mind?
>
> Sounds like a reasonable requirement. Also the command excludes any
> instance which is in down state?
>
> Best regards,
> --
> Tatsuo Ishii
> SRA OSS K.K.
> English: http://www.sraoss.co.jp/index_en/
> Japanese:http://www.sraoss.co.jp
>
> > Nadav Shatz
> > CTO
> >
> >> On Sep 16, 2025, at 7:30 PM, Tatsuo Ishii <ishii(at)postgresql(dot)org> wrote:
> >>
> >> 
> >>>
> >>> Hi Tatsuo,
> >>>
> >>> Sorry for the late reply - I'm traveling with my family at the moment
> (in
> >>> Japan actually)
> >>
> >> Excellent! Hope you and your family are spending great time in Japan.
> >>
> >>> and might be delayed in responding.
> >>
> >> No problem at all. I think you should focus on the travel at this
> >> moment.
> >>
> >>> 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.
> >>
> >> Makes sense. I withdraw my proposal.
> >>
> >>> 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?
> >>
> >> What I am not sure is, whether we can assume the command always knows
> >> which host (or IP) is primary? If the answer is yes, then we could
> >> omit the primary. What do you think?
> >>
> >>> 3 - I agree with you, next version (after we clear everything else)
> will
> >>> have only ip/hostname+port.
> >>
> >> Thank you for understanding.
> >>
> >>> 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
> >
> >
>