3 Topics
Chapter•95 Minutes

Chaos Engineering, Capacity Validation, and Production Readiness

Prove system behavior through realistic load tests, controlled failure injection, recovery drills, and operational reviews.

Load, Stress, Spike, and Endurance Tests

Load tests verify expected traffic, stress tests explore beyond capacity, spike tests test sudden demand changes, and endurance tests reveal leaks or gradual degradation. Each test should have a hypothesis and measurable acceptance criteria.

Use realistic request mixes, payload sizes, authentication, cache states, data distributions, and geographic latency. Validate the load generators themselves so they do not become the bottleneck. Measure throughput, p95/p99 latency, errors, resource saturation, queue age, database lock waits, and dropped work.

A high request rate is not a successful result if requests fail silently or asynchronous work never completes. Test cold and warm cache behavior separately and compare against a stable baseline.

Key Takeaways
  • Choose a test based on a specific capacity question.
  • Use realistic datasets and validate the load generators.
  • Measure correctness and backlog as well as throughput.

Chaos Experiments and Recovery Testing

Chaos engineering tests a resilience hypothesis with controlled failure injection. Examples include killing one instance, adding latency to a dependency, interrupting broker connectivity, or simulating a zone outage. Establish a safety boundary, observe impact, and stop the experiment if the blast radius exceeds the plan.

Test recovery after the fault ends: can queues drain, replicas catch up, clients reconnect, and the system return to its SLO? Random disruption without a hypothesis creates noise. Use staging or carefully controlled production experiments with authorization and rollback.

Record findings as concrete improvements to timeouts, alerts, capacity, runbooks, and architecture. Re-run the experiment to prove the fix works.

Key Takeaways
  • Every experiment needs a hypothesis and safety boundary.
  • Recovery and backlog drain matter as much as detection.
  • Turn findings into owned, testable actions.

Production Readiness Reviews and Game Days

A readiness review checks ownership, SLOs, dashboards, alerts, runbooks, capacity, security, backup/restore, deployment safety, dependency quotas, and escalation. The rigor should match the system's criticality.

A game day rehearses realistic incidents such as a failed database promotion, bad deployment, credential compromise, queue backlog, or regional outage. Measure time to detect, decide, mitigate, and recover. Verify communication and customer-impact assessment as well as technical response.

A documented policy is weaker than evidence from a successful restore drill or failover test. Record accepted risks and name an owner for reviewing them.

Key Takeaways
  • Readiness includes people, processes, and technical controls.
  • Game days validate incident response and recovery.
  • Prefer evidence from drills over assumptions.