doc: Add ClickHouse for GitLab.com readiness review
What
Adds initial blueprint for ClickHouse readiness review.
This readiness review covers the scope of connecting GitLab Rails to a deployed ClickHouse cluster and re-enablement of the integrated error tracking feature.
The runbooks for deployment are still pending completion of operator and architecture discussions so deployment is out of scope initially. Instead we cover failure cases, performance concerns, a high-level architecture for error collection/ingestion, and test cases.
Including:
- Summary
- Key Metrics to monitor
- Operational Risk Assessment
- Performance
- Monitoring and Alerts
- Responsibility
Remainder TBDs of blueprint is placeholder to be completed over coming milestone(s)
Relates to #37 (closed) and gitlab-org/opstrace/opstrace#1644 (closed)
DIY Review app: https://gitlab.com/gitlab-com/gl-infra/readiness/-/blob/add-clickhouse-readiness-review/library/database/clickhouse/index.md#architecture
Status
This MR is currently being broken apart for more dedicated discussions and iterative parts, see
- !115 (merged)
- !117 (merged)
- !118 (closed) (closed in favor of this MR)