Horton

Re: snapbuild woes

Tom Lane <tgl@sss.pgh.pa.us>

View thread View on postgr.es
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Noah Misch <noah@leadboat.com>
Cc: Andres Freund <andres@anarazel.de>, Petr Jelinek <petr.jelinek@2ndquadrant.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Erik Rijkers <er@xs4all.nl>, David Steele <david@pgmasters.net>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>, Craig Ringer <craig@2ndquadrant.com>, pgsql-hackers-owner@postgresql.org
Date: 2017-05-01T12:46:47Z
Lists: pgsql-hackers 
Noah Misch <noah@leadboat.com> writes:
> On Fri, Apr 21, 2017 at 10:34:58PM -0700, Andres Freund wrote:
>> ... I was wondering about adding
>> a loop that simply runs for like 30s and then quits or such, but who
>> knows.

> If the probabilistic test catches the bug even 5% of the time in typical
> configurations, the buildfarm will rapidly identify any regression.  I'd
> choose a 7s test that detects the bug 5% of the time over a 30s test that
> detects it 99% of the time.  (When I wrote src/bin/pgbench/t/001_pgbench.pl
> for a probabilistic bug, I sized that test to finish in 1s and catch its bug
> half the time.  In its case, only two buildfarm members were able to
> demonstrate the original bug, so 5% detection would have been too low.)

30sec is kind of a big lump from a buildfarm standpoint, especially if
you mean "it runs for 30s on my honkin' fast workstation".  I'm fine
with individual tests that run for ~ 1sec.

(This is top-of-mind for me right now because I've been looking around
for ways to speed up the regression tests.)

			regards, tom lane

Commits

  1. Fix thinko introduced in 2bef06d516460 et al.

  2. Avoid superfluous work for commits during logical slot creation.

  3. Fix race condition leading to hanging logical slot creation.

  4. Don't use on-disk snapshots for exported logical decoding snapshot.

  5. Preserve required !catalog tuples while computing initial decoding snapshot.