On 10.15 I'm getting the following on a logically replicated server.
From the CSV logs:
2021-10-13 18:49:39.792 EDT,,,213601,,6143c257.34261,64243,,2021-09-16 18:16:55 EDT,4/3914851,60709901,WARNING,01000,"NOTIFY queue is 66% full",,,,,,,,,""
2021-10-13 18:49:46.058 EDT,,,213601,,6143c257.34261,64244,,2021-09-16 18:16:55 EDT,4/3914855,60709905,WARNING,01000,"NOTIFY queue is 66% full",,,,,,,,,""
2021-10-13 18:49:51.934 EDT,,,213601,,6143c257.34261,64245,,2021-09-16 18:16:55 EDT,4/3914862,60709915,WARNING,01000,"NOTIFY queue is 66% full",,,,,,,,,""
2021-10-13 18:50:00.516 EDT,,,213601,,6143c257.34261,64246,,2021-09-16 18:16:55 EDT,4/3914864,60709917,WARNING,01000,"NOTIFY queue is 66% full",,,,,,,,,""
2021-10-13 18:50:08.003 EDT,,,213601,,6143c257.34261,64247,,2021-09-16 18:16:55 EDT,4/3914871,60709926,WARNING,01000,"NOTIFY queue is 66% full",,,,,,,,,""
The very fine docs for 10 say
"There is a queue that holds notifications that have been sent but not yet processed by all listening sessions. If this queue becomes full, transactions calling
NOTIFY will
fail at commit. The queue is quite large (8GB in a standard
installation) and should be sufficiently sized for almost every use
case. However, no cleanup can take place if a session executes LISTEN and then enters a transaction for a
very long time. Once the queue is half full you will see warnings in
the log file pointing you to the session that is preventing cleanup.
In this case you should make sure that this session ends its current
transaction so that cleanup can proceed."We do have a client that has access to this logically replicated server and I have no idea what they have done regards LISTEN/NOTIFY, and my query to them about this has not yielded a response.
In the CSV logs above what part points to "the session that is preventing cleanup" so that I can kill it? pg_stat_activity yields no clues.
Thanks,
Jeff
