Accessing metrics through Grafana UI or Grafana/Mimir APIs

Question asked on Slack:

is there a place where I can run a promql query like we used to do with thanos? I'm trying to get some numbers out from a grafana dashboard do we have a 1y retention? My data dies before feb 2024

Answered by @reprazent:

We rolled out Mimir in Q1 of last year, so that's when the data starts, which is likely what you're seeing there The query interface for mimir is grafana's /explore thing, for better or worse If you need the data older than that, you can still query thanos, but the data will stop with some overlap

We could add a docs page to given overview of:

1. Why and when did we switch to Mimir?
2. Consequences for metrics availability
3. Retention strategy for metrics data
4. How to query metrics through Grafana UI
5. How to programmatically retrieve metrics through Grafana API or Mimir API (and what type of access needed)