Re: [PATCH] libpq: try all addresses for a host before moving to next on target_session_attrs mismatch

On Thu, Mar 12, 2026 at 5:22 PM Zsolt Parragi <zsolt(dot)parragi(at)percona(dot)com>
wrote:

> In a happy eyeballs analogy, one approach might want to connect to all
> listed IPs at the same time, and return the first that responds and is read
> write.
>

I would hope that "the first" read write is also "the only" read write. If
you have a multi-leader situation, you almost certainly want to be quite
precise about who connects to what, and not leave that up to the whims of
the network gods.

I'm still a big +1 to the original proposal in this thread, and don't think
it would be incompatible with happy eyeballs. Although I would think the
latter would be quite wasteful, as we are not simply checking for a
response, but doing a whole connect/authenticate/get-status dance. Is a
quicker response more important than querying every IP in the list every
time? I dunno. Maybe that's a future argument to target_session_attribs.[1]

[1] Yes, I know, but that's what the name should have been. Or even
"attributes"

Cheers,
Greg