Re: [PROPOSAL] Termination of Background Workers for ALTER/DROP DATABASE

Alexander Lakhin <exclusion@gmail.com> writes:

I think this can explain slow CommitTransactionCommand() and why it
happens not every time. Regarding other animals, I guess they can
experience the same bumps but not exceeding 5 seconds (50 tries). Thus,
from my understanding, for the failure to happen, we need to have slow
storage and initialize_worker_spi() -> CommitTransactionCommand() reaching
XLogFileClose().

So, it remains not very clear why only widowbird is showing this
failure, but I think we can safely take away the bottom-line
conclusion that hard-wiring a maximum wait of 5s in
CountOtherDBBackends() was not a great idea.

There also were two failures from jay: [1], [2], but yes, widowbird is
getting more and more consistent in that aspect: [3], probably because
of the storage (SD card?) degradation.

Tomas, maybe you could check if the write speed is more or less acceptable
there?

Regarding the test-specific fix, let me remind of the other failure from
widowbird: [4].

[1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=jay&dt=2026-03-10%2019%3A26%3A19
[2] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=jay&dt=2026-03-24%2020%3A43%3A24
[3] https://buildfarm.postgresql.org/cgi-bin/show_history.pl?nm=widowbird&br=master
[4] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=widowbird&dt=2025-10-25%2010%3A35%3A03

Best regards,
Alexander