Why You Should Move From Monolith to Microservices

In this article, we’ll talk about microservices and how to shift to it from a monolith architecture. We’ll find out how to adapt to such changes with minimum risks for your organization. In fact, we’ll figure out how to accomplish this with benefits. Excited? Let’s jump right into it. 

First, let’s discuss why you must make such a transit. At a certain point, you may find yourself in a situation where adding new essential features to an existing codebase becomes difficult and time-consuming. Moreover, it turns out that the cost of a new functionality outweighs the benefits it may bring. The solution to this challenge might be microservices. 

Sigma Software team regularly helps our clients with such assignments, and we have already experienced first-hand that with common sense, proper skill, and competent planning, refactoring to microservices becomes a feasible task that can substantially simplify further development and maintenance activities.

What Are Microservices?

There is no clear definition for it. So, let’s stick to Jonathan Johnson and Laura Shiff’s description: Microservices are a specific method of designing software systems to structure a single app as a collection of loosely coupled services. 

Instead of a monolithic approach, each microservice component has: 

• Own CPU 
• Own runtime environment 
• A dedicated team working on it 

This architecture means each service can run its unique process and communicate autonomously without relying on the other microservices or the application as a whole. 

It has become a trend for many organizations. Such corporate giants as Amazon, Uber, and Netflix already implemented this architecture. The idea is simple: extracting massive components into multiple, deployable, and self-sufficient functional entities grouped by a particular purpose. Every element is responsible for its specific functions and interacts with other components through an API. 

Advantages 

This adoption may bring your company many benefits, including improvements in resilience, high scalability, faster time to market, smooth maintenance, etc. 

However, the migration process may be quite challenging, especially for organizations that operate large and complex systems with a monolithic architecture. However, the good thing is that microservices can coexist peacefully with any monolithic program. 

You can stretch this migration process in time, thus reducing immediate cost and effort loading and staying fully operational through the whole process. Moreover, you don’t necessarily need to move the entire solution to microservices. You can go with a hybrid strategy, extracting only those parts that become hard to handle inside the monolith and keeping the rest of the functionality unchanged. 

Why Convert?

The typical monolithic architecture includes such problems as a slow delivery process, system scalability, defects detection, verification difficulties, and so on. Software parts are tightly combined inside this architecture thus, even the slightest changes affect the whole app or program and require redeployment. This ends with a very time-consuming and painstaking operation. The same goes for scalability. You need to scale the entire application. 

Well-designed and implemented microservices help address these issues by splitting up the large app into the tiniest components divided by specific domains and communicating with each other via APIs. However, for the end-users, it looks like a single application. 

Each of these services can be created, tested, and changed separately. If something fails — your development team will be able to quickly fix this without affecting the work of the whole app. 

To sum up, the benefits are the following: 

• Easier deployment and maintenance 
• Reduced downtime through fault isolation 
• Flexibility in choosing tech stack and easier scalability 
• Simplified coordination within the teams 

However, once you introduce such architecture, integration becomes a challenge. This requires special attention to both the design, implementation, and testing part of the transition process. 

Switch Smartly 

The transition from monolith requires careful and thoughtful planning. The best thing is to start by cutting off parts of the functionality from the monolith one after another, step by step. Use an iterative approach and keep those parts small. This will reduce migration risks, and you’ll have better control over the whole process. 

Extract everything that can be isolated first. Only after that will the remaining functionality be dealt with. It can be rewritten into separate microservices from scratch or left within the monolith. Either way, it will be far easier to maintain after most of the functionalities have already been detached. 

With this approach, a typical process would include the following steps: 

Planning 

Identify microservice candidates and create a backlog.

First and foremost, you need to create a backlog for microservices adoption. To do this, you need to identify candidates — parts that should be turned into separate microservices. Then you need to prioritize those to form a queue for further transition.  

Of course, the best option would be if those candidates are functional groups that can be isolated from the monolith with minimum effort. Also, it would be good if they could solve some of the issues your application already has. 

The most obvious candidate would be an area with specific resource and performance utilization issues. Or it could be a domain area that will unblock other microservices' separations. 

If you are looking for a more inclusive approach to determining what can be detached from the monolith, the best strategies that you can apply during your switch to microservices would be: 

1. Dividing the app into layers 
2. Splitting the app into the domain areas 
3. Dividing the app into the modules 

Iterative implementation (this set of steps is repeated for each microservice) 

• Choose the refactoring strategy 
• Design the microservice and change according to CI/CD and testing process 
• Set up CI/CD 
• Implement microservice 

Ensure you have available professionals to take care of your entire migration process. 

Conclusion 

Moving to microservices is undoubtedly not an easy task, although it can be simplified if done sequentially. They have advantages, but there must be excellent reasons for such a switch. It requires great effort and highly skilled specialists who can plan and execute the migration. 

You can think of such migration if your existing architecture has become too complex to operate and manage and put your best efforts into strategy and design. Today, scalability and agility are keys to success — microservices provide both. With the proper planning, design, and implementation, investments in migration will pay off quite quickly.