DO378 Red Hat Cloud-Native Microservices Development with Quarkus — Lesson 2: Data Access, Transactions, Validation, Security, and External Services

Learning Objectives

• Explain the structures, services, data, settings, roles, and dependencies governing Panache and persistence and transactions.
• Implement and validate bean validation, service security, and REST clients using reviewable evidence.
• Evaluate the condition where a change succeeds in one environment but fails elsewhere because inventory, policy, version, or runtime assumptions differ and select a proportionate corrective response.

Detailed Topics

• Panache and persistence applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• transactions applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• bean validation applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• service security applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• REST clients 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 a change succeeds in one environment but fails elsewhere because inventory, policy, version, or runtime assumptions differ.

Hands-On Exercise

Complete a controlled Red Hat exercise covering Data Access, Transactions, Validation, Security, and External Services 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 Panache and persistence.
• 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 “a change succeeds in one environment but fails elsewhere because inventory, policy, version, or runtime assumptions differ” 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 Data Access, Transactions, Validation, Security, and External Services, explain the resulting platform behavior, and defend the outcome through the Quarkus microservice repository, API and data design, test evidence, and OpenShift deployment portfolio.