DO328 Building Resilient Microservices with Istio and Red Hat OpenShift Service Mesh — Lesson 4: Fault Injection, Resilience Testing, Troubleshooting, Rollout, and Operations

Learning Objectives

• Operate, troubleshoot, document, and improve fault injection, resilience testing, and troubleshooting.
• Apply rollout and operations while preserving reviewable technical evidence.
• Recognize and correct the risk where the technical fix is successful but monitoring, rollback, ownership, or handover remains incomplete.

Detailed Topics

• fault injection: apply the concept to a platform and development team improving reliability and visibility for distributed microservices, record the relevant settings or decisions, and explain the operational consequence.
• resilience testing: apply the concept to a platform and development team improving reliability and visibility for distributed microservices, record the relevant settings or decisions, and explain the operational consequence.
• troubleshooting: apply the concept to a platform and development team improving reliability and visibility for distributed microservices, record the relevant settings or decisions, and explain the operational consequence.
• rollout: apply the concept to a platform and development team improving reliability and visibility for distributed microservices, record the relevant settings or decisions, and explain the operational consequence.
• operations: apply the concept to a platform and development team improving reliability and visibility for distributed microservices, record the relevant settings or decisions, and explain the operational consequence.

Instructor Demonstration

The instructor demonstrates fault injection, resilience testing, troubleshooting, rollout, and operations by tracing the relevant architecture, commands, configuration, messages, and evidence. The walkthrough highlights how the technical fix is successful but monitoring, rollback, ownership, or handover remains incomplete and shows how to isolate the cause without masking dependent issues.

Hands-On Exercise

Run an operational review and produce support-ready evidence for Fault Injection, Resilience Testing, Troubleshooting, Rollout, and Operations. Add verified outcomes to the service mesh configuration, traffic policy tests, observability evidence, and resilience runbook.

1. Confirm the scope, versions, access, dependencies, and success criteria.
2. Perform the workflow while recording commands, settings, output, and platform events.
3. Test one expected case and one controlled exception specific to this lesson.
4. Retest the correction and document ownership, rollback, and follow-up actions.

Scenario Analysis

• Identify which dependency most strongly influences fault injection in the stated scenario.
• Compare two approaches for rollout and explain the security, reliability, and support trade-offs.
• Decide what evidence must be retained in the service mesh configuration, traffic policy tests, observability evidence, and resilience runbook before operational acceptance.

Troubleshooting Guidance

Begin with the first observable difference from the expected result. Check monitoring, troubleshooting, rollback, ownership, and handover separately, then correlate logs, events, commands, and configuration history. Do not accept the initial assumption that the technical fix is successful but monitoring, rollback, ownership, or handover remains incomplete; confirm the cause with a reproducible retest.

Validation Checklist

• The required monitoring, troubleshooting, rollback, ownership, and handover were checked and recorded.
• The normal path and a course-specific exception were tested.
• The service mesh configuration, traffic policy tests, observability evidence, and resilience runbook links conclusions to commands, configuration, logs, or other objective evidence.
• Corrective actions, rollback steps, ownership, and handover notes are complete.

Lesson Outcome

Learners can apply Fault Injection, Resilience Testing, Troubleshooting, Rollout, and Operations, explain the observed Red Hat platform behavior, and support the result with a reviewable service mesh configuration, traffic policy tests, observability evidence, and resilience runbook.