Deployment Strategies

In DevOps, deployment refers to the process of making software applications or updates available for use. There are several types of deployment strategies that organizations can use, depending on their specific needs and requirements. Here are some common deployment strategies in DevOps.

Blue-green deployment

Blue-green deployment is also referred to as red/black deployment. This deployment allows you to introduce a new version (green) of your application in parallel with the existing version (blue). Once the new version in the green environment is deemed ready and has undergone successful testing, traffic is redirected from the blue environment to the green environment. This switch can be done by adjusting a load balancer or DNS settings.

This approach allows you to minimize downtime and reduce the risk associated with deploying new versions of an application.

Canary deployment

Canary deployment involves rolling out a new release to a small subset of users before the full release. This allows real-world testing and monitoring of the new version's performance and stability. If the canary group experiences no issues, the deployment can be expanded to the entire user base.

Canary deployment helps mitigate the risk of introducing bugs or performance issues to a large user base by initially exposing a small fraction of users to the changes.

In-place deployment

In this deployment method, the operational application on every instance within the deployment group must undergo a cessation. Subsequently, the most recent application version is installed on these instances before restarting the application. After initiating the application, a validation process is required. The Elastic Load Balancer (ELB) can facilitate the deregistration of each instance during its deployment, subsequently restoring it to service once the deployment process concludes.

Unlike some other deployment strategies that require maintaining separate environments (e.g., blue-green), in-place deployment minimizes the need for additional infrastructure. There's no need to manage duplicate sets of servers.

In-place deployment is often used in scenarios where the application can tolerate a brief period of unavailability or reduced performance. It may be more suitable for applications with lower criticality or for updates that are not expected to cause significant disruptions.

A/B testing deployment

A/B testing is mainly employed to assess the impact and market response to a modification. The introduction of new features will be implemented for a specific group of users. This deployment is also known as split testing.

This deployment method involves two groups: a control group (A) and an experimental group (B). The control group experiences the existing version (the "baseline"), while the experimental group is exposed to a modified version (the "variant"). This testing is often an iterative process. Based on the results of a test, further iterations may be conducted to refine changes and continually improve the product.

Shadow deployment

In a shadow deployment, the new version of the application is deployed alongside the existing version. The new version processes requests in parallel with the old version, but the responses from the new version are not sent to users.

The primary purpose of a shadow deployment is to observe and analyze the behavior of the newer version in a real-world setting. Developers can monitor logs, metrics, and other performance indicators to assess how the shadow version performs under realistic conditions.

Conclusion

These are some widely used deployment strategies in the software development process. The choice of deployment strategy depends on factors such as the application's criticality, user impact, and the organization's risk tolerance.