Re: [PATCH] Allow Postgres to pick an unused port to listen

Hi Robert,

On Tue, Apr 11, 2023 at 12:54 AM Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Fri, Apr 7, 2023 at 5:34 PM Yurii Rashkovskii <yrashk(at)gmail(dot)com> wrote:
> > I'm trying to understand what's wrong with reading port from the pid
> file (if Postgres writes information there, it's surely so that somebody
> can read it, otherwise, why write it in the first placd)? The proposed
> solution uses operating system's functionality to achieve collision-free
> mechanics with none of the complexity introduced in the commit.
>
> I agree. We don't document the exact format of the postmaster.pid file
> to my knowledge, but storage.sgml lists all the things it contains,
> and runtime.sgml documents that the first line contains the postmaster
> PID, so this is clearly not some totally opaque file that nobody
> should ever touch. Consequently, I don't agree with Tom's statement
> that this would be a "a horrid way to find out what was picked." There
> is some question in my mind about whether this is a feature that we
> want PostgreSQL to have, and if we do want it, there may be some room
> for debate about how it's implemented, but I reject the idea that
> extracting the port number from postmaster.pid is intrinsically a
> terrible plan. It seems like a perfectly reasonable plan.
>
>
I appreciate your support on the pid file concern. What questions do you
have about this feature with regard to its desirability and/or
implementation? I'd love to learn from your insight and address any of
those if I can.

--
Y.