Re: scalability bottlenecks with (many) partitions (and more)

Andres Freund <andres@anarazel.de>

From: Andres Freund <andres@anarazel.de>

To: Tomas Vondra <tomas@vondra.me>, Tom Lane <tgl@sss.pgh.pa.us>, Andrew Dunstan <andrew@dunslane.net>

Cc: Jakub Wartak <jakub.wartak@enterprisedb.com>, Robert Haas <robertmhaas@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-03-04T19:09:24Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Make FP_LOCK_SLOTS_PER_BACKEND look like a function
- c878de1db438 18.0 landed
Fix asserts in fast-path locking code
- a7e5237f268e 18.0 landed
Increase the number of fast-path lock slots
- c4d5cb71d229 18.0 landed

Hi,

On 2025-03-04 19:58:38 +0100, Tomas Vondra wrote:
> Pushed, with the tweaks to use FastPathLockSlotsPerBackend() in a couple
> more places.

Thanks!


> I noticed sifaka started failing right after I pushed this:
> 
> https://buildfarm.postgresql.org/cgi-bin/show_history.pl?nm=sifaka&br=master
> 
> But I have no idea why would this cosmetic change cause issues with LDAP
> tests, so I'm assuming the failure is unrelated, and the timing is
> accidental and not caused by the patch.

The buildfarm was updated between those two runs.

https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=sifaka&dt=2025-03-04%2015%3A01%3A42
has
                                          'PGBuild::Log' => 'REL_18',
whereas the failing run
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=sifaka&dt=2025-03-04%2017%3A35%3A40
has
                                          'PGBuild::Log' => 'REL_19',

It's worth noting that
a) sifaka doesn't build with ldap support
b) the failure is in checkprep, not when running the tests
c) the buildfarm unfortunately doesn't archive install.log, so it's hard to
   know what actually went wrong

Greetings,

Andres Freund