[REQUEST]: New Observability threshold rule

[lcawl]

Description

Per https://github.com/elastic/actionable-observability/issues/36 there's a new rule that will combine three previous (logs threshold, infrastructure threshold, and metrics threshold) Observability rules, though I think all four will continue to exist in parallel for a little while.

Per @katrin-freihofner she has discussed with @mdbirnstiehl and they have added a link from the new rule to the docs (currently just a stub file), but will ultimately be similar to the existing rule-specific pages in this section: https://www.elastic.co/guide/en/observability/master/create-alerts.html

Resources

• https://github.com/elastic/actionable-observability/issues/36
• Design figma file
• [AO] Add Threshold rule Doc link  kibana#160045

Collaboration

TBD. The docs and product team will work together to determine the best path forward.

Point of contact.

Main contact:

Stakeholders:
@katrin-freihofner

[katrin-freihofner]

This rule is behind a feature flag - we can postpone the documentation for it to 8.10

[mdbirnstiehl]

Due to a privilege issue, this has been pushed to 8.11.