0.3.0 prometheus warning log

[DeoLeung]

Describe the bug
too much warning log

pgcat-collector_1         | [2022-10-09T01:19:54.868493Z WARN  pgcat::prometheus] Metric avg_errors not implemented for survey_shard_0_primary
pgcat-collector_1         | [2022-10-09T01:19:54.868573Z WARN  pgcat::prometheus] Metric avg_errors not implemented for survey_shard_1_primary
pgcat-collector_1         | [2022-10-09T01:19:54.868618Z WARN  pgcat::prometheus] Metric avg_errors not implemented for survey_shard_2_primary

To Reproduce
start a new one, make a connection with wrong pool name

Expected behavior
implement it or less verbose

Additional context
It will be nice to have pools_client_active_connections and databases_database_current_connections as well :)

[levkk]

The warning is coming from here. We could downgrade that to debug! instead. If you'd like to make a PR, I'd be happy to merge it.

It would be a good idea to take a look at our metrics and make sure that Prometheus and admin DB are in sync here, or ideally, pull metrics from the same source.