Too many connections error

Percona Monitoring and Management (PMM) PMM 1.x
1

I spun up a pmm 1.0.6 server. After enabling qan on about 60 servers I get errors like:

2016/12/08 19:20:13 server.go:2317: http: response.WriteHeader on hijacked connection
2016/12/08 19:20:13 server.go:2317: http: response.Write on hijacked connection
2016/12/08 19:20:13.252 127.0.0.1 500 705.712µs WS /agents/f47e5df7c29446a04ea13530da9a21d2/data
ERROR 2016/12/08 19:20:14 init.go:229: auth agent: auth.MySQLHandler.GetAgentId: dbm.Open: Error 1040: Too many connections

Is this a parameter I can change?

Any ideas about how many mysql instances I could support with a single pmm server if I only run qan?

Thanks!

2

In theory, it is only limited by the amount of resources available for container or underlying host.

Looks like there is an issue with MySQL in the container “Error 1040: Too many connections”
If you enter container how many connections do you see?

docker exec -it pmm-server mysql -vv -e ‘show processlist’

3

152 rows of:

| 11521 | qan-api | localhost:33840 | pmm | Sleep | 2752 | | NULL |
| 11550 | qan-api | localhost:33953 | pmm | Sleep | 2744 | | NULL |
| 11551 | qan-api | localhost:33956 | pmm | Sleep | 40 | | NULL |
| 11567 | qan-api | localhost:34054 | pmm | Sleep | 2732 | | NULL |
| 11568 | qan-api | localhost:34056 | pmm | Sleep | 14 | | NULL |
| 11805 | qan-api | localhost:35108 | pmm | Sleep | 2645 | | NULL |
| 11806 | qan-api | localhost:35110 | pmm | Sleep | 2645 | | NULL |
| 11820 | qan-api | localhost:35179 | pmm | Sleep | 2642 | | NULL |
4

Seems like I can handle around 25 mysql servers

5

We have found 1 potential place in the code where it may not close connections. In the next release next week.