Before microservices, the standard way of building an application was monolithic architecture. Basically, all the parts of the application were bundled together in one code, or in other words, all components are part of a single unit in a monolithic architecture.
For example, if we have an online e-commerce store application, all of its parts, such as user authentication, shopping cart, product catalog, notification, payment, and so on, would be part of one big monolithic application, where all the code for these features and functionality would be in one code base. Everything is developed, deployed, and scaled as one unit. This means that the application must be written in one single language with one technology stack with a single runtime.
If multiple teams work on different parts of the application then they have to coordinate with each other so that they won’t affect each other’s work. In order to update one functionality of an application, the dev team must update the whole application since one functionality cannot be updated separately. In the past, this was the standard method of developing applications, but as the size and complexity of the applications increased, new challenges arose.
The opposite of monolithic architecture is the microservices style of building software applications. In this small, independently deployed units work together as a single unit. Typically, these small independent units are called microservices and are organized around business capabilities. Each microservice or micro application is designed to meet a specific business need and is highly modular in design. Data storage, Google analytics, CRM, ERP, Push notification, etc, are some examples of microservices.
Through well-defined interfaces and protocols, these small components communicate with each other. For example, a payment service needs some data from the user account to process the payment and the checkout service needs something from the shopping cart. A very common way microservices talk to each other is through API calls. Each service has an endpoint on which it accepts requests from the other service. So, services can talk to each other by sending each other HTTP requests on these endpoints. Communication between services occurs synchronously, where one service sends a request to another service and waits for its response. Because of the architectural style of microservice applications, it is very easy and efficient to manage them.
Some reasons to use microservices:
1. Less Complexity
In monolithic architecture, as an application grows, it becomes more complex. Due to the large code size and interconnected parts of the application, this happened. A microservice architecture can help the company to break down the different large complex applications into smaller and more manageable units. Due to the fact that each unit of the application is independent of the other, changes in one part of the application do not affect the rest.
2. Better Scalability
You cannot scale up a single part of a monolithic application without scaling the whole application. It means higher infrastructure costs and less flexibility in scaling up and down your application. Scaling up specific parts of the application independently is possible and is easier in microservices because each microservice is a self-contained independent unit.
3. Enhanced agility
Another major issue with monolithic applications is that the release process of such applications takes a long time. In order to deploy changes in one part of the application, you must build the entire application and test it for errors and bugs. The work of one development team can be affected by the mistakes made by another.
On the other hand, microservices are modular in nature allowing more flexibility and agile development as teams can work on different microservices in parallel and deploy them independently.
4. Greater flexibility
5. Identifying and fixing problems
Due to their large single code, finding problems in monolithic applications are difficult to find and fix. In contrast, in a microservice application, the issue can be identified and fixed more quickly and without affecting other parts of the application.
6. Better maintainability
In microservice applications, each microservice is focused on a specific part of the business (for example, Purchase, Product, Customer, Notification, Marketing, Data, etc.) capability. It also makes the codebase easier to maintain. For instance, if a problem arises in a purchase-related microservice, the company can fix it faster without affecting other parts of the application.
It is now clear that microservices are software design patterns that use modular components to build a large application. In a microservice application, each component can be deployed independently and scaled separately. Communication between these components takes place through APIs and other protocols. Due to the way microservice applications work, faster development cycles, higher code quality, and easier maintenance are all possible.