servers on a rackAs we’ve identified in previous articles, the Strangler Pattern approach provides a valuable strategy for breaking down legacy applications into smaller, more manageable components while keeping your existing system intact and operating.

In this article, we turn to the implementation process in the context of an IBM i application, where we break the application down and identify key considerations for a successful transition.

Understanding the Application First

The rigidity of legacy applications makes them a challenge to modify with often-critical enhancements in any environment. Tightly coupled components and dependencies lead to a lack of flexibility, scalability, and agility, standing between you, your organization, and successful modernization. We need to break the application down into smaller components.
How do we go about it?

Identifying Boundaries for Microservices

The first step in implementing the Strangler Pattern is the most important: identify the opportunities and boundaries for microservices within the application.

This step benefits from intimate knowledge of the IBM i application, its functionality, and all of the cohesive and independent modules within that can be extracted as separate services.
If you do have that understanding, take the time to document it. If you don’t, map it out with deep analysis and report the results. If you’re not satisfied with the results yet, take another look until you’re comfortable with your understanding.

When you’ve completed the decomposition process, you’ll be in a solid position to identify the best opportunities to get started extracting functionality into separate services.

Decoupling Dependencies

Once your application is successfully and comfortably mapped out, you should have good candidates to start decoupling from the system. Then, you can just rank the best opportunities and get started.

Once you’ve targeted your opportunities, it is essential to decouple these dependencies methodically.

You have several techniques at your disposal to approach the process, including refactoring, encapsulation, and the introduction of well-defined interfaces.

Incremental Development and Deployment

One of the key advantages of the Strangler Pattern is its incremental nature. Rather than attempting to replace the entire application at once, you will gradually develop and deploy the new components, lowering your risk.

You can validate the new functionality and performance of the modernized services at a sustainable pace and see far fewer failures or disruptions from start to implementation.

Testing and Validation

It’s a good idea to verify that you have a thorough testing and validation process locked into place and ready before you implement a Strangler Pattern strategy to ensure the reliability and compatibility of the new microservices. Your results will depend on it.

This includes unit testing, integration testing, and end-to-end testing. Additionally, consider implementing automated testing frameworks and tools to streamline the testing process and ensure the effectiveness of the modernized components.

Benefits of Component-Based Approach

Breaking down IBM i applications into smaller components brings several benefits:

Enhanced Agility

Agility is critical in today’s competitive environment, and the Strangler Patter will get you there with its component-based approach. As a result, new features or updates can be implemented without affecting the entire system.

Scalability

You can scale individual services based on demand by decoupling components and introducing microservices. This granular scalability improves resource utilization and ensures optimal performance.

Technology Adoption

Breaking the application down allows you to leverage modern technologies, frameworks, and programming languages to develop microservices. You’ll now be able to take advantage of advancements in the software development ecosystem.

CM First Evolve IT and the Strangler Pattern

CM evolveIT can help IT Managers master a Strangler Application implementation in an IBM i system with tools and services to analyze applications, identify boundaries for microservices, and facilitate the development and integration of new components.

The platform’s impact analysis capabilities can help identify dependencies and potential risks before making changes. It ensures a smooth transition by providing insights into the impact of breaking down the monolith.

Additionally, Evolve IT assists in the code generation process, simplifying the development of new microservices. This accelerates the implementation process and ensures the modernized components align seamlessly with the existing system.

By embracing the Strangler Pattern and partnering with CM First, your organization can transform its IBM i applications into modular and future-proof systems that meet the demands of today’s rapidly evolving business landscape.

Start your modernization journey with CM First today and unlock the potential of your legacy applications.