> 5 апр. 2018 г., в 19:58, Magnus Hagander <mag...@hagander.net> написал(а): > > > > On Thu, Apr 5, 2018 at 4:55 PM, Andrey Borodin <x4...@yandex-team.ru> wrote: > > > > 5 апр. 2018 г., в 14:33, Tomas Vondra <tomas.von...@2ndquadrant.com> > > написал(а): > > > > This patch version seems fine to me. I'm inclined to mark it RFC. > +1 > The patch works fine for me. I've tried different combinations of backend > cancelation and the only suspicious thing I found is that you can start > multiple workers by cancelling launcher and not cancelling worker. Is it > problematic behavior? If we run pg_enable_data_checksums() it checks for > existing launcher for a reason, m.b. it should check for worker too? > > I don't think it's a problem in itself -- it will cause pointless work, but > not actually cause any poroblems I think (whereas duplicate launchers could > cause interesting things to happen). > > How did you actually cancel the launcher to end up in this situation? select pg_enable_data_checksums(10000,1); select pg_sleep(0.1); select pg_cancel_backend(pid),backend_type from pg_stat_activity where backend_type ~ 'checksumhelper launcher' ; select pg_enable_data_checksums(10000,1); select pg_sleep(0.1); select pg_cancel_backend(pid),backend_type from pg_stat_activity where backend_type ~ 'checksumhelper launcher' ; select pg_enable_data_checksums(10000,1); select pg_sleep(0.1); select pg_cancel_backend(pid),backend_type from pg_stat_activity where backend_type ~ 'checksumhelper launcher' ;
select pid,backend_type from pg_stat_activity where backend_type ~'checks'; pid | backend_type -------+----------------------- 98587 | checksumhelper worker 98589 | checksumhelper worker 98591 | checksumhelper worker (3 rows) There is a way to shoot yourself in a leg then by calling pg_disable_data_checksums(), but this is extremely stupid for a user. Best regards, Andrey Borodin.
