Re: Problem with pg_notify / listen

David G. Johnston <david.g.johnston@gmail.com>

From: "David G. Johnston" <david.g.johnston@gmail.com>

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>

Date: 2020-11-27T14:28:10Z

Lists: pgsql-bugs

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Fix a recently-introduced race condition in LISTEN/NOTIFY handling.
- f6324bbbe63c 10.16 landed
- f5de090cc175 13.2 landed
- cbc7a7a10c2d 12.6 landed
- 9c83b54a9ccd 14.0 landed
- 8a4069766079 9.6.21 landed
- 60d6c71430f9 9.5.25 landed
- 40f2fbe71ad6 11.11 landed
Prevent concurrent SimpleLruTruncate() for any given SLRU.
- d4031d78460c 11.10 cited

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.