Blue/Green Deployments

A Blue/Green deployment model consists of two production environment: one live and the other is for upgrading. Once the non-live environment is upgraded and tested it is switched to be the live state while the other becomes idle. The transition involves directing all traffic from one environment to the other.

Cloud Deployment Challenges

Implementing the Blue/Green deployment model enhances platform reliability and user satisfaction by reducing the following risks and challenges associated with application updates:

• Application Downtime During Updates: Traditional deployment methods often require taking the system offline, leading to user dissatisfaction and potential revenue loss.
• Complex Rollback Processes: In the event of a failed deployment, reverting to a previous stable version can be cumbersome and time-consuming.
• Environment Discrepancies: Differences between testing and production environments can lead to unforeseen issues upon release.

Benefits of Blue/Green Deployments

1. Zero Downtime Deployments: Users experience uninterrupted service during application updates, maintaining a consistent user experience.
2. Simplified Rollbacks: If the new version exhibits issues, traffic can be reverted to back the previous working environment, ensuring stability.
3. Enhanced Testing in Production: The idle environment allows for rigorous testing under real world conditions before making it live to users.

Reliable and Efficient Deployment Process.

Blue/Green deployment strategies reduces risks and ensures a consistent user experience by enabling smooth traffic switching and safe rollbacks.

Blue/Green - Implementation Steps

1. Set up identical production environments

Establish two identical production environments, designated as Blue and Green.

Implementation Details:

• Replicate the current production setup to create a parallel production environment.
• Ensure both environments are consistently configured using Infrastructure as Code (IaC) tools like Ansible, Terraform or Pulumi.
• Create a runbook for redirecting traffic from one environment to the other environment.
• Create a runbook for the rollback plan to ensure that switching back to a previous working environment can be done quickly and seamlessly.

2. Update the idle production environment

Deploy a new application version to the environment that is not currently receiving live traffic.

Implementation Details:

• Use a CI/CD process to deploy an application update to the idle production environment

3. Conduct rigorous testing

Validate the new version in the idle environment to identify and resolve any potential issues before going live.

Implementation Details:

• Run functional tests to confirm that all application features work as expected.
• Run performance tests to simulate real world loads to ensure stability under high traffic conditions.
• Run security tests to scan for vulnerabilities to prevent potential exploits.
• Run other types of tests as required.

4. Redirect live traffic to the updated environment

Once testing is successful, redirect live traffic to the production environment using the updated application.

Implementation Details:

• Follow your runbook to modify routing configurations to use load balancers or DNS updates to shift traffic to the new environment.
• Monitor performance in real time to observe application behaviour post switch to detect any anomalies early.
• Re-designate your two production environments. The production environment now receiving the live traffic is active and the other production environment is idle.

5. Monitor and roll back if necessary

Continuously track system performance and be prepared to revert to the previous version if any issues arise.

Implementation Details:

• Use tools like Prometheus, Grafana, or AWS CloudWatch for real-time system insights.
• If an issue arises, follow your runbook to carry out the rollback plan to switch back to the preview working environment.