[Logs UI/Design] Improve log rate visualization

[weltenwort]

Summary

The visualization of the log rate and its anomalies should be simplified to increase focus and to accomodate partitioning of the analysis.

Rationale

In the current state the log rate visualization is an incomplete imitation of the anomaly explorer in the ML UI. Instead it would serve the use-cases better if it was tailed towards representing the relevant information in a less generic, more summarized fashion. Additionally the upcoming introduction of partitioning the ML job will require the chart to display multiple rates simultaneously while making sure anomalies are easily spotted.

Acceptance criteria

The chart...

• Displays the overall log rate across all partitioned values, as a baseline
• Shows a simple signifier on buckets that have a > 0 max anomaly score (across all partitioned values)
• Possibly displays information about which partitioned value(s) had the n highest severity scores in that bucket, either on hover, click, or some other way
• Links to the ML UI for further investigation

Further notes

• Consider visually highlighting anomalies in specific buckets, possibly
  • via color intensity or
  • via a color palette and thresholds that match the ML UI's, based on anomaly severity
• The number of partitioned values could be above 10 depending on the log source diversity.
• The ML UI uses a quantized color palette from blue over orange to red to represent anomaly severity intervals.

[elasticmachine]

Pinging @elastic/infra-logs-ui

[jasonrhodes]

@weltenwort @hbharding @katrin-freihofner @tbragin @Kerry350 I edited these AC slightly to reflect the conversations we had in our meeting today. Please feel free to add comments here if you think I've misrepresented anything. Thanks!

We should have a smaller meeting focused on this design issue somewhat soon, @hbharding @katrin-freihofner can you let us know how much time you'd like to consider these AC as written and think through some simple solutions so we can talk them through this week?

[weltenwort]

ℹ️ There's a dedicated implementation issue for the ML UI link at #46445, which we should update once the design work has progressed.

[Kerry350]

Now that we've had the design handoff I'm going to close this ticket, and open a ticket strictly for the implementation (there are a few smaller points still in discussion / pending finalisation, but they can be facilitated during implementation).

[katrin-freihofner]

I just recognized I haven't documented the outcome here.