Separate liveness from database readiness
A brief database outage makes the process liveness endpoint fail. The restart policy kills every API instance and turns a recoverable connection issue into a restart loop.
- Focused work estimate
- 2h + prerequisites
- Priority in the scenario
- High
- Engineering practice
- Health checks · Dependency failures · Operational contracts
Estimated field mix
- Site reliability60%
- Platform engineering40%
Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence.
Review it, then add it to your workspace.
The board opens an editable draft; nothing is saved until you confirm it. Sign-in and workspace permissions apply, and Demo boards remain ephemeral.
Project context
A fictional scheduling service has an API, a worker, and PostgreSQL. Releases use immutable images on two application instances. The team needs compatibility checks, staged traffic, and a rehearsed rollback without introducing a new orchestration platform.
Setup prerequisites
- HTTP health checks
- CI pipelines
- Database migrations
Preceding work
No earlier ticket is required. Complete the project setup above.
Acceptance criteria
- Liveness reports whether the process can serve its own health handler.
- Readiness fails when required database operations cannot complete within a bounded timeout.
- Dependency errors return a stable diagnostic code without connection strings.
Implementation constraints
- A readiness probe must not create user records or run migrations.
Verification to include
- Assert both probes succeed with healthy synthetic dependencies.
- Disable the database and verify readiness fails while liveness remains successful.
Deliverables
- Separate health routes and dependency-outage reproduction
Rollout and recovery
Switch traffic readiness first, then restart-policy probes; restore prior routing if probe semantics are misconfigured.
Value of the work
For the engineer: Practice release contracts, compatibility windows, measurable canaries, and incident decisions on a modest application topology.
For the team: Review whether an engineer can make deployments diagnosable and reversible while identifying when rollback is unsafe.
Evidence boundaries
Outcome Evidence: Tests, patches, and runbooks are requested deliverables. They become Outcome Evidence only through a qualified Mission and immutable Evidence IDs.
Ownership Evidence: Independent adaptation must be observed under a declared verification policy and cite immutable Evidence IDs. Completing a planning ticket establishes no Ownership Evidence.