On Thu, Apr 14, 2022 at 07:45:15PM -0700, Noah Misch wrote: > On Thu, Apr 14, 2022 at 06:52:49PM -0700, Andres Freund wrote: > > On 2022-04-14 21:32:27 -0400, Tom Lane wrote: > > > Peter Geoghegan <p...@bowt.ie> writes: > > > > Are you aware of Andres' commit 02fea8fd? That work prevented exactly > > > > the same set of symptoms (the same index-only scan create_index > > > > regressions), > > > > > > Hm. I'm starting to get the feeling that the real problem here is > > > we've "optimized" the system to the point where repeatable results > > > from VACUUM are impossible :-( > > > > The synchronous_commit issue is an old one. It might actually be worth > > addressing it by flushing out pending async commits out instead. It just > > started to be noticeable when tenk1 load and vacuum were moved closer. > > > > > > What do you think about applying a polished version of what I posted in > > https://postgr.es/m/20220414164830.63rk5zqsvtqqk7qz%40alap3.anarazel.de > > ? That'd tell us a bit more about the horizon etc. > > No objection. > > > It's also interesting that it only happens in the installcheck cases, > > afaics, not the check ones. Although that might just be because there's > > more of them... > > I suspect the failure is somehow impossible in "check". Yesterday, I cranked > up the number of locales, so there are now a lot more installcheck. Before > that, each farm run had one "check" and two "installcheck". Those days saw > ten installcheck failures, zero check failures. > > Like Tom, I'm failing to reproduce this outside the buildfarm client. I wrote > a shell script to closely resemble the buildfarm installcheck sequence, but > it's lasted a dozen runs without failing.
But 24s after that email, it did reproduce the problem. Same symptoms as the last buildfarm runs, including visfrac=0. I'm attaching my script. (It has various references to my home directory, so it's not self-contained.)
repro-wrasse-vis.sh
Description: Bourne shell script
