Horton

Re: NOTIFY does not work as expected

Jeff Janes <jeff.janes@gmail.com>

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From: Jeff Janes <jeff.janes@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andrey <parihaaraka@gmail.com>, Pg Bugs <pgsql-bugs@postgresql.org>
Date: 2018-07-03T16:30:11Z
Lists: pgsql-bugs 
On Tue, Jul 3, 2018 at 1:28 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:

> Jeff Janes <jeff.janes@gmail.com> writes:
> > On Mon, Jul 2, 2018 at 4:33 PM, Andrey <parihaaraka@gmail.com> wrote:
> >> [ delayed receipt of notifications ]
>
> > I don't think this is a bug.   I don't see that the docs promise one
> > behavior over the other, so it is really a dealer's choice.  Also, I
> can't
> > reliably reproduce the reported 9.6.2 behavior on my own 9.6.2 server.
>
> FWIW, it looks like a bug to me.  I don't have time to investigate
> further right now, though.  It's also not at all clear whether the
> issue is in the server or libpq or psql ...
>

In my hands, it bisects down to this:

commit 4f85fde8eb860f263384fffdca660e16e77c7f76
Author: Andres Freund <andres@anarazel.de>
Date:   Tue Feb 3 22:25:20 2015 +0100

    Introduce and use infrastructure for interrupt processing during client
reads.

But that was committed in 9.5.dev, not between 9.6.2 and 9.6.9.

It is on the server side.  This is testing with psql, and it doesn't seem
to matter which version of it.  Maybe there is something between 9.6.2 and
9.6.9 that shows up with another client or more.

Cheers,

Jeff

Commits

  1. Client-side fixes for delayed NOTIFY receipt.

  2. Server-side fix for delayed NOTIFY and SIGTERM processing.

  3. Introduce and use infrastructure for interrupt processing during client reads.