[feature/proposal] Creating a dedicated page for metrics explorer

[Allen Serhat]

When using the current metrics explorer the window overlays on top of the query window and only displays the metric name. When running a query I feel like it is important to understand the meaning of the metric which the help text is for in my opinion.

I was interested to see what it would look like in its own page displaying the metric name and the help text to highlight what the metric means.

I have done the work to see what it would look like in the UI and used the metadata API to gather the needed information.   I opened up a PR in the event there is interest and was looking for feedback to see if this would be considered, otherwise I can clean up the PR to keep the repo hygiene in order.

https://github.com/prometheus/prometheus/pull/12566

Thank you,

Allen Serhat

[Julien Pivotto]

Thanks! This is what we have from our developer summit notes::



Filip: Metrics explorer in Prometheus
https://github.com/prometheus/prometheus/issues/11181
Prometheus lacks a UI to visualize metrics with their label names, label values and overall cardinality.
The api/v1/status/tsdb endpoint only exposes top 10 metrics by cardinality, but does not show why they have high cardinality (which labels contribute the most).
The only way to get the information out of Prometheus is to use the api/v1/series API which is expensive and slow because it expands all series.
An example of what a metrics explorer looks like in DataDog is shown in the issue from the first bullet point.
Augustin: We have it in PromLens, should move to Prometheus
Julien: Julius wanted to move some stuff over from there
Filip: What about performance?
MR: Can TSDB give us more?

CONSENSUS: We want to support this. We will have a configurable limit to prevent impact on alerting and/or scraping performance by default. We will explore a new API for this.