Grafana alerts pending when using proxysql as datasource

[Benjamin Roob]

Hi,

we try to connect our Grafana (v.7.3.7) with a proxysql 1.4 as mysql datasource. This will work fine for any dashboard panels. But it does not work if an alert rule is applied to a panel.
The state of the alert is pending between "no data" and ok. So for every second alert execution we get this error message:

Execution Error: tsdb.HandleRequest() response error &{dial tcp 127.0.0.1:6033: connect: connection refused A 0xc00106ef20 [] [] []}

I can not find any hint in grafana logs - set log level to info. 

If we switch back to a " real mysql server" everything works as expected.
But our idea is to send queries of panels to read only servers within a hostgroup.

Any ideas or advise to get this scenario working? Or is it simply impossible to achieve this at the moment?

Best regards,
Ben