Triage and recover runbooks

Map failure classes for ingest worker + queue metrics: retryable vs fatal vs needs-human. Retries need budgets, jitter, and idempotency rules aligned to every command is copy-pasteable; mutating steps need change ticket; verify after each step. The chapter’s signature failure — runbook says 'restart something' without naming deployment or verifying lag — must take a deliberate branch, not a generic catch-all.

Implement the degrade/rollback/refuse behavior secondary on-call clearing ingest.lag_minutes > 45 needs when INC-INGEST-9021 repeats. Prefer scoped controls (one flag, one weight, one tenant, one secret version) over fleet-wide restarts. Preserve evidence; do not delete logs to “clean the demo.”

After containment, check drill_completion_minutes and lag_minutes moves in the safe direction and watch for retry amplification. Write the stop condition that ends the incident response for this lab.

Chaos note: inject only one fault class at a time and restore fixtures after. Watch for dual failures — dependency down and retry amplifier — which is how runbook says 'restart something' without naming deployment or verifying lag becomes an outage. Customer communication templates (even if only for the drill) beat silence. If you queue deferred work, define poison-message handling. Budget documents should state the maximum extra spend allowed during retries. Close the loop by linking the containment action to a dashboard panel for drill_completion_minutes and lag_minutes.

Draw a state diagram for degrade modes and put it in the repo as ASCII if needed. Cap concurrent retries across the process, not only per request. Ensure cancellation propagates to downstream HTTP clients. When failing closed, choose a user-visible message that does not leak internals. Practice the single command that flips the kill switch or weight to zero. After recovery, drain or inspect deferred work before declaring green. In this chapter the product is executable queue-backlog runbook for embedding ingestion pipeline, the human stakeholder is secondary on-call clearing ingest.lag_minutes > 45, and the incident id you design against is INC-INGEST-9021. Re-state the oracle in your notes — drill INC-INGEST-9021: lag 60→5 minutes in ≤ 25m following runbook v1.4 — and keep the invariant visible: every command is copy-pasteable; mutating steps need change ticket; verify after each step. Track drill_completion_minutes and lag_minutes as the scoreboard. Surface under change control: ingest worker + queue metrics. If you only have forty minutes, finish the fixture for runbook says 'restart something' without naming deployment or verifying lag before polishing UI. Promotion language stays ternary: promote, hold, or roll back based on evidence, not hope.