Zero-Downtime Deployment Planning

Plan a zero-downtime deployment step by step.

Change description:
{{change_description}}

Current architecture:
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Traffic pattern: {{traffic_pattern}}

Think through systematically:

1. CHANGE CLASSIFICATION: Is this a stateless, database, or breaking change?

2. BACKWARD COMPATIBILITY: Is the new version compatible with the old?

3. DATABASE CHANGES: Are there schema changes? How to handle them?

4. DEPLOYMENT STRATEGY: Blue-green, canary, or rolling?

5. TRAFFIC SHIFTING: How will traffic be shifted to new version?

6. HEALTH CHECKS: What checks confirm the new version is healthy?

7. ROLLBACK PLAN: How do we roll back quickly if issues arise?

8. SESSION HANDLING: How are active sessions affected?

9. DEPENDENCY ORDERING: Which services need to deploy first?

10. MONITORING: What metrics confirm successful deployment?

11. RUNBOOK: Step-by-step deployment instructions.