How to limit monitor account number?

[zard14]

Description

HI I check the document, and it can limit monitor account conncetion number.

ALTER USER monitor CONNECTION LIMIT 2;

https://docs.percona.com/percona-monitoring-and-management/setting-up/client/postgresql.html#create-a-database-account-for-pmm

Because I find out if I have five user db, each userdb will open 4 connections, and there will be 20 ilde connctions finally.

If I limit user account "monitor" number as 2, there are only two connections right, but there will be bunch of fatal errors in postgresql log like this.

2022-11-16 01:07:52.590 -04 [493080] monitor@postgres 192.168.XXX.XXX(44096)FATAL: too many connections for role "monitor"

All suggestions are welcome, Thank you!

Expected Results

1.No fatal errors in postgresql

2. lower monitor account conncetions

Actual Results

bunch of fatal errors in postgresql log like this.

2022-11-16 01:07:52.590 -04 [493080] monitor@postgres 192.168.XXX.XXX(44096)FATAL: too many connections for role "monitor"

Version

pmm server 2.32 pmm client 2.32

Steps to reproduce

No response

Relevant logs

No response

Code of Conduct

• [X] I agree to follow Percona Community Code of Conduct

[denisok]

@tshcherban is this because we had a fix for it before, but now we have upstream changes: https://github.com/percona/postgres_exporter/blob/main/cmd/postgres_exporter/server.go#L72

https://github.com/prometheus-community/postgres_exporter/pull/655

?

[artemgavrilov]

Hello @zard14 , since PMM 2.42 there is an option that limits connections amount for PG: https://docs.percona.com/percona-monitoring-and-management/setting-up/client/postgresql.html#maximum-connection-limit