Обсуждение: Old query lying around in pg_stat_activity for weeks
Was alerted to an old query lying around in the pg_stat_activity view on a little used server recently. It ha no values for wait_event_type or wait_event and had an idle state value. The query_start value was about two weeks old. Odd, but after verifying it had no pg_lock lookup, I canceled it.
Might there be an infrequent staleness of items that appear in the pg_stat_activity view that is just understood to be there from time to time?
On Fri, Mar 26, 2021 at 07:16:42AM -0400, Jacque Edmund wrote: > Was alerted to an old query lying around in the pg_stat_activity view on a > little used server recently. It ha no values for wait_event_type or > wait_event and had an idle state value. The query_start value was about > two weeks old. Odd, but after verifying it had no pg_lock lookup, I > canceled it. > > Might there be an infrequent staleness of items that appear in the > pg_stat_activity view that is just understood to be there from time to time? If the state is "idle" it means it's only a connection doing nothing, it's not really consuming any resources. You also can't cancel it, since it isn't doing anything, just close it. The best thing to do if you don't have persistent connections or a connection pooler is to check where the connection coming from and investigate what could be the client/application responsible for leaking an idle connection.
On Fri, 2021-03-26 at 19:25 +0800, Julien Rouhaud wrote: > On Fri, Mar 26, 2021 at 07:16:42AM -0400, Jacque Edmund wrote: > > Was alerted to an old query lying around in the pg_stat_activity view on a > > little used server recently. It ha no values for wait_event_type or > > wait_event and had an idle state value. The query_start value was about > > two weeks old. Odd, but after verifying it had no pg_lock lookup, I > > canceled it. > > > > Might there be an infrequent staleness of items that appear in the > > pg_stat_activity view that is just understood to be there from time to time? > > If the state is "idle" it means it's only a connection doing nothing, it's not > really consuming any resources. You also can't cancel it, since it isn't doing > anything, just close it. > > The best thing to do if you don't have persistent connections or a connection > pooler is to check where the connection coming from and investigate what could > be the client/application responsible for leaking an idle connection. I guess Jacque is confused by the "query" column. It does not necessarily show a query that is currently running, it just shows the most recent query in the session. If "state" is "idle", the query is already finished. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com