Test health checks signals and thresholds

Instrument Kubernetes liveness vs readiness for retrieval-and-generation API so cluster operator during vector DB maintenance window can answer: demand, errors, latency/age, saturation. Emit fields needed by restart_count == 0 during dep outage and ready_pods ≥ 1 when deps healthy with bounded labels. Sample successful high-volume traces; keep errors and rollout transitions denser within policy.

Define at least one alert that would fire for PROBE-RESTART-STORM-8, with a for/pending window that survives deploy blips. Missing scrape or missing revision labels must not look like health. Include a trace/log example id format you will actually search.

Add a unit/integration check that metrics increment on the happy path and on the readyz embedded in liveness → restart storm during dependency blip branch. Store machine-readable output in CI artifacts when practical.

Cardinality discipline: tenant and revision are usually enough; raw question text is not a label. Exemplars or trace links beat screenshots alone when debugging PROBE-RESTART-STORM-8. Define who owns alert fatigue review. If you export to a vendor, record retention and access. Synthetic probes should use non-sensitive fixtures and still exercise GET /livez and GET /readyz. Practice the query you will type at 2am once, while calm.

Document the exact PromQL or log query in the runbook stub for this service. Verify histograms have buckets around your SLO target. Add a canary synthetic check that exercises the oracle path every few minutes in staging. Confirm that PII redaction happens before export. Track build/version as a label on the golden signals. Delete noisy debug logs before they become accidental product dependencies. In this chapter the product is Kubernetes liveness vs readiness for retrieval-and-generation API, the human stakeholder is cluster operator during vector DB maintenance window, and the incident id you design against is PROBE-RESTART-STORM-8. Re-state the oracle in your notes — vector pause → readyz 503, livez 200, no restart loop; process deadlock → livez fails → restart — and keep the invariant visible: /livez only checks process; /readyz checks vector+model deps; wrong probe kills healthy pods. Track restart_count == 0 during dep outage and ready_pods ≥ 1 when deps healthy as the scoreboard. Surface under change control: GET /livez and GET /readyz. If you only have forty minutes, finish the fixture for readyz embedded in liveness → restart storm during dependency blip before polishing UI. Promotion language stays ternary: promote, hold, or roll back based on evidence, not hope.