DO378 Red Hat Cloud-Native Microservices Development with Quarkus — Lesson 3: Testing, Resilience, Messaging, Observability, and Performance

Learning Objectives

• Explain the structures, services, data, settings, roles, and dependencies governing unit and integration testing and fault tolerance.
• Implement and validate messaging, metrics and tracing, and native performance using reviewable evidence.
• Evaluate the condition where operators cannot explain the outcome because logs, commands, settings, and acceptance evidence were not captured consistently and select a proportionate corrective response.

Detailed Topics

• unit and integration testing applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• fault tolerance applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• messaging applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• metrics and tracing applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• native performance applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.

Instructor Demonstration

The instructor traces a Java development team modernizing a monolithic service into observable, resilient Quarkus microservices. The walkthrough connects navigation, commands, configuration logic, system messages, and evidence captured in the Quarkus microservice repository, API and data design, test evidence, and OpenShift deployment portfolio. It also tests the exception where operators cannot explain the outcome because logs, commands, settings, and acceptance evidence were not captured consistently.

Hands-On Exercise

Complete a controlled Red Hat exercise covering Testing, Resilience, Messaging, Observability, and Performance and preserve the verified result in the Quarkus microservice repository, API and data design, test evidence, and OpenShift deployment portfolio.

1. Confirm scope, prerequisites, versions, identities, dependencies, and acceptance criteria.
2. Execute the workflow while recording commands, settings, outputs, events, and system messages.
3. Test normal behavior, one boundary condition, and the stated exception.
4. Document corrections, evidence, ownership, retest criteria, rollback, and handover actions.

Scenario Analysis

• Identify which object, service, policy, setting, or sequence most strongly influences unit and integration testing.
• Compare two defensible responses and explain technical, security, operational, and support trade-offs.
• Determine how the Quarkus microservice repository, API and data design, test evidence, and OpenShift deployment portfolio should be approved, retained, retested, and updated.

Troubleshooting Guidance

Start where expected behavior first differs from the observed result. Check prerequisites, identity, configuration order, version compatibility, connectivity, status, resource limits, and evidence separately. Treat “operators cannot explain the outcome because logs, commands, settings, and acceptance evidence were not captured consistently” as a hypothesis until commands, logs, settings, and retest outcomes confirm the cause.

Validation Checklist

• Required platform components, identities, permissions, settings, and dependencies are present.
• The Quarkus microservice repository, API and data design, test evidence, and OpenShift deployment portfolio connects each conclusion to objective, reviewable evidence.
• Normal processing, a boundary condition, dependency behavior, and the stated exception were tested.
• Corrections, ownership, retest criteria, rollback, documentation, and operational handover are complete.

Lesson Outcome

Learners can apply Testing, Resilience, Messaging, Observability, and Performance, explain the resulting platform behavior, and defend the outcome through the Quarkus microservice repository, API and data design, test evidence, and OpenShift deployment portfolio.