> On 24 Apr 2025, at 22:49, Roman Khapov <rkha...@yandex-team.ru> wrote:
>
> Hi!
> Recently we faced a problem in out production psql installation, which was
> that we had to cancel all requests to the db, including performance
> monitoring requests, that uses ps_stat_statements. But we could not cancel
> the request in usual way, and had to kill -9 the pg process of it.
Interesting problem, thanks for raising it!
> We've noticed that the the query execution stuck on PGSS_TEXT_FILE file
> reading in function qtext_load_file, which doesn't have CHECK_FOR_INTERRUPTS
> in the read cycle. In addition to our case with large PGSS_TEXT_FILE (and
> maybe the problems with virtual disk i/o) that can explain uncancellable
> pg_stat_statements queries.
I'm afraid it might be not so easy to add CHECK_FOR_INTERRUPTS there. Most
probably you was holding a LWLockAcquire(pgss->lock, LW_SHARED) somewhere (do
you have a backtrace?), which prevent interrupts anyway.
Thanks!
Best regards, Andrey Borodin.
