Microservices are small, independent components that together form an application. Each microservice performs a specific function and can be deployed and scaled separately from other microservices. This architecture allows developers to create complex, scalable, and resilient web applications.
Microservices architecture emerged in response to the problems of monolithic architecture - large and complex applications that are a single entity and are deployed and scaled together. When developing monolithic applications, it is difficult to make code changes, as one change can affect the entire system. In addition, monolithic applications are difficult to scale and make resilient.
Microservices solve these problems by breaking the application into small components, each of which performs its own function and can be deployed and scaled separately from other components. This allows developers to quickly and flexibly make code changes, scale individual components, and ensure high system resilience.
Microservices can be written in different programming languages and use different technologies and tools. They can be deployed in various containers, such as Docker, and interact with each other through REST APIs. Each microservice can be deployed and scaled independently and can use its own database and other external services.
One of the main advantages of microservices architecture is the ability to develop web applications according to the Continuous Delivery principle - continuous development and delivery of new features and fixes to production in the shortest possible time. This is achieved thanks to the independence of each microservice and the ability to make code changes and deploy it independently of other components.
Another advantage of microservices is the ability to scale the system based on load. As the number of users and requests grows, new instances of microservices can be added and the performance of the system can be increased. With the use of monolithic architecture, such scaling would be difficult.
In addition, microservices allow for the creation of systems that can be easily scaled at different levels - from individual services to high-level components. Such systems can be easily modified and adapted to requirements and market changes.
Microservices also simplify system development and security. As the application is split into small components, each of them becomes simpler and more understandable for developers. This allows for independent development and testing of components and simplifies programming and debugging.
However, microservices architecture has its drawbacks. The main one is the complexity of interaction and coordination between different microservices. Since each microservice performs its own function and can use its own database and external services, it is necessary to establish means of communication between the components. This requires additional work and expenses.
In addition, when using microservices, there is a need for careful version control and dependency management. Since each microservice can be developed and deployed independently, it is necessary to monitor updates and compatibility between components. In addition, it is necessary to manage and control the resources of each microservice, such as memory and processor time.
Despite these drawbacks, microservices represent a revolution in web application development. They allow for the creation of complex and scalable systems that can be easily modified and adapted to changes in requirements and market conditions. This architecture allows developers to quickly develop and deliver new features and fixes to the user and ensures high application resilience and scalability.