3.4.8 Application Rollbacks

Perform Application Rollbacks

Per Service

ServiceRollback Method
CodeDeployAuto on failure/alarm, redeploy previous
CloudFormationAuto on failure, --disable-rollback for debug
LambdaUpdate alias to previous version
ECSRoute traffic to original task set
BeanstalkRedeploy previous version

CodeDeploy Auto Rollback

DeploymentPreference:
  Type: Canary10Percent5Minutes
  Alarms:
    - !Ref ErrorAlarm
  • Triggers: Deployment failure, CloudWatch alarm
  • Action: Redeploy last known good revision

Lambda Rollback

aws lambda update-alias --function-name my-func \
  --name prod --function-version 5  # Previous version

CloudFormation Rollback

# Stuck in UPDATE_ROLLBACK_FAILED
aws cloudformation continue-update-rollback \
  --stack-name my-stack \
  --resources-to-skip BrokenResource

Exam Tip: CodeDeploy + Alarms = auto rollback. Lambda = update alias. CloudFormation continue-update-rollback for stuck stacks.