Question

How do you manage blue-green deployments in a serverless architecture?

This question focuses on implementing blue-green deployment strategies within serverless frameworks, like AWS Lambda or Google Cloud Functions. It seeks mechanisms for minimizing downtime, controlling traffic shifts between versions, and providing rollback options during deployments, all while addressing the specific pain points of stateless, serverless-based solutions.

Answer 1

Serverless environment blue-green deployments must be managed with care to minimize the time lost and ensure traffic is handed smoothly over as follows:

Version Management: A new version of the function will be deployed while the old one is retained via your serverless framework (such as Google Cloud Functions traffic splitting, AWS Lambda versions or aliases).
Traffic Splitting: Gradually hand traffic from the current version (blue) to the new version (green). For AWS Lambda, use AWS Lambda Aliases with weighted routing.
Automated Testing: Thorough testing with canary traffic or synthetic requests before full traffic hits the new environment.
Variables and Feature Flags: Using feature flags to control what feature flag is activated in the new deployment. Utilize quick rollback if issues arise in that deployment.
Monitoring and Rollback: Implement monitoring for latency, error rates, and other key metrics during the switchover. If problems are identified, roll back traffic to the blue environment immediately
Infrastructure as Code (IaC): Use IaC tools such as AWS SAM, Serverless Framework or Terraform to ensure consistent deployments across environments.