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Commits from this thread:
2020-11-28 9c83b54a9c cbc7a7a10c 40f2fbe71a 8a40697660 60d6c71430 f6324bbbe6 f5de090cc1 Fix a recently-introduced race condition in LISTEN/NOTIFY handling.
* Problem with pg_notify / listen
@ 2020-11-27 12:56 Gustavsson Mikael <mikael.gustavsson@smhi.se>
2020-11-27 14:28 ` Re: Problem with pg_notify / listen David G. Johnston <david.g.johnston@gmail.com>
2020-11-27 15:21 ` Re: Problem with pg_notify / listen Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 2 replies; 3+ messages in thread
From: Gustavsson Mikael @ 2020-11-27 12:56 UTC (permalink / raw)
To: pgsql-generallists.postgresql.org <pgsql-general@lists.postgresql.org>; +Cc: Svensson Peter <peter.svensson@smhi.se>; Almen Anders <anders.almen@smhi.se>
Hi.
After applying the latest patch we have encountered a problem with the pg_notify queue.
The queue is filling up and starts issuing warnings like
WARNING: NOTIFY queue is 87% full
DETAIL: The server process with PID 2969993 is among those with the oldest transactions.
NOTIFY queue cannot be emptied until that process ends its current transaction.
There is no long-running 'active' or 'idle in transaction' transactions on the server.
We restarted the application with the said pid but the result was that the new process pid appeared in the logs instead.
We tried to stop everything except postgresql it self but the queue was not purged. After restarting postgresql the queue is empty and seems to be holding up for an hour or so before it starts growing again.
We have been using pg_notify / listen for about three years and haven’t run in to this problem before so it seems to me that something happened in the latest patch.
PG version: 11.10 with slony. The notify triggers is on the master node.
KR.
Mikael Gustavsson
SMHI
Swedish Meteorological and Hydrological Institute
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Problem with pg_notify / listen
2020-11-27 12:56 Problem with pg_notify / listen Gustavsson Mikael <mikael.gustavsson@smhi.se>
@ 2020-11-27 14:28 ` David G. Johnston <david.g.johnston@gmail.com>
1 sibling, 0 replies; 3+ messages in thread
From: David G. Johnston @ 2020-11-27 14:28 UTC (permalink / raw)
To: Gustavsson Mikael <mikael.gustavsson@smhi.se>; +Cc: pgsql-generallists.postgresql.org <pgsql-general@lists.postgresql.org>; Svensson Peter <peter.svensson@smhi.se>; Almen Anders <anders.almen@smhi.se>
On Friday, November 27, 2020, Gustavsson Mikael <mikael.gustavsson@smhi.se>
wrote:
> Hi.
>
> After applying the latest patch we have encountered a problem with the
> pg_notify queue.
>
> The queue is filling up and starts issuing warnings like
> WARNING: NOTIFY queue is 87% full
> DETAIL: The server process with PID 2969993 is among those with the
> oldest transactions.
> NOTIFY queue cannot be emptied until that process ends its current
> transaction.
>
> There is no long-running 'active' or 'idle in transaction' transactions on
> the server.
>
>
As its easy enough to run can you please confirm this by showing us the
pg_stat_activity record for that pid during the time when this warning
appears?
Thanks!
David J.
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Problem with pg_notify / listen
2020-11-27 12:56 Problem with pg_notify / listen Gustavsson Mikael <mikael.gustavsson@smhi.se>
@ 2020-11-27 15:21 ` Tom Lane <tgl@sss.pgh.pa.us>
1 sibling, 0 replies; 3+ messages in thread
From: Tom Lane @ 2020-11-27 15:21 UTC (permalink / raw)
To: Gustavsson Mikael <mikael.gustavsson@smhi.se>; +Cc: pgsql-generallists.postgresql.org <pgsql-general@lists.postgresql.org>; Svensson Peter <peter.svensson@smhi.se>; Almen Anders <anders.almen@smhi.se>
Gustavsson Mikael <mikael.gustavsson@smhi.se> writes:
> After applying the latest patch we have encountered a problem with the pg_notify queue.
What do you mean by "the latest patch", exactly?
regards, tom lane
^ permalink raw reply [nested|flat] 3+ messages in thread
end of thread, other threads:[~2020-11-27 15:21 UTC | newest]
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2020-11-27 12:56 Problem with pg_notify / listen Gustavsson Mikael <mikael.gustavsson@smhi.se>
2020-11-27 14:28 ` David G. Johnston <david.g.johnston@gmail.com>
2020-11-27 15:21 ` Tom Lane <tgl@sss.pgh.pa.us>
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