Deployment strategy selection and troubleshooting

Exam alignment: DOP-C02 Domain 1 task statements for pipelines, testing, artifacts, or deployment.

Learning objective

Select strategies by platform, risk, capacity, validation, and rollback, then diagnose evidence systematically.

Difficulty / Schwierigkeitsgrad	Advanced
Study time / Lernzeit	120 minutes
Prerequisites / Voraussetzungen	Previous lessons in this volume

Professional scenario

EC2, ECS, and Lambda teams each need different release behavior.

Core concepts

• In-place modifies live hosts.
• Rolling replaces part of current capacity.
• Blue/green preserves old and new environments.
• Canary and linear progressively expose a version.

Architecture flow

1. Identify the release input and immutable identity.
2. Select the managed AWS control plane and least-privilege role.
3. Execute build, test, artifact, or deployment work.
4. Collect service events, logs, reports, and runtime metrics.
5. Stop, retry, or roll back according to explicit rules.

Decision matrix

Requirement	Preferred choice	Reason
EC2 with little spare capacity	In-place if downtime allowed	Avoid duplicate fleet
ECS pre-traffic test	Blue/green	Validate green
Lambda 10% first	Canary alias	Weighted native rollout

Failure modes and troubleshooting

• Wrong artifact version.
• Deployment role or runtime role is missing permissions.
• Target is healthy but business metric fails.

Security and operations

• Use short-lived service roles and least privilege.
• Encrypt artifacts and protect logs from secret exposure.
• Record changes and approvals for audit.

Hands-on lab

Goal / Ziel: Solve six platform scenarios and one game day.

Tasks

1. Create the smallest safe test architecture.
2. Implement or simulate the main workflow.
3. Introduce one controlled failure.
4. Diagnose it from service evidence.
5. Document cleanup and one improvement.

Validation

• The workflow uses an immutable version.
• A required failure blocks promotion.
• The diagnosis identifies the first failed transition.

Cost control / Kostenkontrolle: Keep resources short lived; read cleanup before starting.

Cleanup

1. Delete pipeline/build/deployment resources.
2. Delete temporary artifacts, images, logs, and roles.

Exam traps

• One strategy for all platforms.
• Random configuration changes instead of evidence.

Key takeaways

• In-place modifies live hosts.
• Canary and linear progressively expose a version.
• Decisions must be justified by requirements and failure behavior.

Review questions

1. What is the immutable release identity?
2. Which evidence proves failure or success?
3. What is the safest recovery action?

Answers

1. A version, digest, or uniquely versioned artifact.
2. Service events, logs, reports, health checks, and runtime metrics.
3. Restore the known-good version using the configured rollback path.