Zero-Downtime Deployment on AWS
Implementing automated blue/green, canary, and rolling deployments on AWS using ALB, Jenkins CI/CD, and CloudFront.
Executive Summary
A global collaboration platform required zero-downtime deployment on AWS. By using an ALB, VPC, S3 with CloudFront, and a Jenkins CI/CD pipeline supporting rolling, blue/green, and canary releases, we enabled automated, reliable deployments with instant rollbacks and optimized network performance.
Why AWS
AWS was selected for its high availability, low-latency networking, and strong scalability. Its CI/CD ecosystem and fast rollback features enabled zero-downtime releases while maintaining reliability and resilience.
The Challenge
A B2B messaging platform serving enterprise teams needed zero-downtime, high-speed deployments, but its AWS setup was manual, making rollbacks slow and increasing operational risk. An automated deployment process was essential to maintain availability and performance.
Architectural Decisions
Zero-Downtime Strategy
- Blue/Green deployment for major version releases:
-
• Jenkins automatically manages rollback by tracking the previous environment and switching target groups in ALB within less than 12 sec if health checks fail.
- Canary deployment for patch versions:
-
• Traffic is gradually shifted using weighted target groups in ALB.
• Jenkins dynamically adjusts canary percentages based on real-time metrics (latency, error rate) to ensure safe rollout. - Rolling deployments for config-only changes:
-
• Instances are updated in batches to maintain service availability.
• ALB health checks ensure only healthy instances receive traffic.
• Jenkins orchestrates batch size and pauses rollout automatically if error thresholds are exceeded.
• Previous instance group is preserved temporarily to allow fast rollback if needed.
stage('Blue/Green Switch') {
steps {
script {
sh """
aws elbv2 modify-listener \
--listener-arn ${LISTENER_ARN} \
--default-actions Type=forward,TargetGroupArn=${NEW_TG_ARN}
"""
sleep 30
def unhealthy = sh(
script: """
aws elbv2 describe-target-health \
--target-group-arn ${NEW_TG_ARN} \
--query 'TargetHealthDescriptions[?TargetHealth.State!=\`healthy\`]' \
--output text
""",
returnStdout: true
).trim()
if (unhealthy) {
echo "Health check failed — rolling back"
sh """
aws elbv2 modify-listener \
--listener-arn ${LISTENER_ARN} \
--default-actions Type=forward,TargetGroupArn=${OLD_TG_ARN}
"""
error("Deployment rolled back")
}
}
}
}
Performance & Stability Measurements
Load Test
- 450 concurrent clients
- 25,000 messages over 20 minutes
- File uploads: 8.5GB mixed content
| Metric | Value |
|---|---|
| Avg API latency | 124 ms |
| WebSocket drops | 0.4% |
| Deployment downtime | 0 sec |
| RDS CPU | 48–55% |
| Canary failure rate | ~3% |
Results & Benefits
The deployment framework delivered zero-downtime releases with blue/green and canary strategies, instant rollback under 12 seconds, and fast asset delivery via S3 + CloudFront. Internal users now experience sub-150 ms response times, while a fully isolated VPC and auditable CI/CD history ensure security and reliability. Over the past 30 days, uptime reached 99.996%, demonstrating the effectiveness of the automated, repeatable infrastructure.