Monolith Vs Microservices Architecture

Monolithic and microservices architecture are the two most common approaches to designing and building software systems. Monolithic architecture is the traditional way of building things, whereas microservices architecture is the modern trend. In this article, let's understand the design and look at some of the key differences between these two architectures.

The monolithic architecture is the standard and more of a traditional way of deploying applications. This is probably how you are building applications right now. It results in a system that is tightly coupled and difficult to modify, as any modification to one part requires modification to the entire system.

Let us look at the sample representation of monolithic architecture👇

When a user sends some request to access or modify a particular data, it will go into the request handler; it could be some middleware or router or anything that reads the request and sends it to the right destination be it the Feature A or Feature B, or Feature C. Suppose the request is sent to Feature C and Feature C might decide to read or write data in the Database and send it back to the user.

All the components like features, routing, logic, and database access are part of a single unit or one codebase. And everything is developed, deployed, and scaled as one unit. This whole architecture is called Monolith architecture.

Simplicity: Monolithic architecture is simple and straightforward which makes it easier to understand and work with.

Ease of development: Since the system is built as a single, cohesive unit, it can be easier to develop and test than more complex architectures.

Good performance: Monolithic systems can have good performance since all of the components of the system are optimized to work together.

The application is too large and complex to fully understand.

Difficult to update or modify individual components of the system since it is built as a single, cohesive unit.

Difficult to scale since the entire system must be scaled together.

Lack of scalability might lead to increased costs and decreased flexibility.

Difficulty with parallel development because it is difficult for multiple developers to work on the system simultaneously.

On every change, the entire application needs to be tested which consumes a lot of time and resources.

Now that we understood monolith architecture, to overcome all these challenges, we adopt a different kind of architecture called microservice architecture.

Unlike monolithic architecture, microservice architecture will have all of the features, routing, logic, and database access to implement one particular feature of our app.

With this microservices architecture, we can now separate all the different features and group them into individual services. Service A has all the code required to make Feature A work correctly and the same goes for other features as well. Each service has its own database.

In microservices, we split applications into smaller, independent services. Usually, each service is made responsible for only one particular job. If any of the services goes down for some reason, other services will still run and serve the application.

For example in an e-commerce website, if the payment system goes down, we just have to rebuild it and deploy it separately, no other features like a shopping cart, or products will be affected.

Now the question is how to do these different independent services will communicate with each other.

Here are some of the communications ways,

Communication using API calls (Synchronous communication).

Communication using Message Broker (Asynchronous communication).

Communication through Service Mesh.

Modularity and flexibility: Each service is independent of the other hand hence it is easy to update or modify the individual components.

Resilience: Each service is independent, a failure in one service does not affect the rest of the system.

Scalability: Microservices are built using distributed architecture which allows them to easily scale horizontally.

Improved productivity: Breaking an application down into smaller modules makes it easier to build and maintain.

Added complexity: Each service is independent, hence it can be more difficult to ensure that all the services are working together properly.

Difficulty with debugging and testing: Difficult to monitor when the system is down or which service is the reason for the system faults.

Increased development time: Because they are independent, it takes up a lot of time than monolithic architecture to develop the application.

In this article, we have seen the monolithic and microservices architecture and their advantages and disadvantages. I hope the article has helped you understand them better.

Thanks for reading till the end! Please share and like the article if it has been helpful to you. Until then, happy reading!