[Bug] Incorrect prometheus metric label names in Temporal server metrics grafana dashboard.

[jupudibhaskar967]

We are trying to integrate the Temporal Server Metrics grafana dashboard on our self managed grafana server and some of charts are not displaying any data.

Description

In the server metrics grafana dashboard, there is a section (row) where there is information about Workflow completion stats and currently all those charts are not displaying any data even with valid metrics. After taking a closer look at the prometheus queries, all the queries are using sum aggregations on the label name "temporal_namespace" but the temporal server pods are publishing metrics with label name "namespace" and because of this mismatch, the charts are not working. Basically, all the charts under this section are not displaying anything.

Example metric from worker pod:

Temporal server version: 1.19.0