Microservices Made Simple: Exploring Common Patterns for Building Scalable Systems

API Gateway Pattern:

An API gateway serves as a single entry point for clients to interact with multiple microservices. It acts as a proxy, routing requests from clients to the appropriate microservices and aggregating their responses. For instance, in a social media application, the API gateway can handle requests for user profiles, posts, and notifications, and it would forward those requests to the corresponding microservices responsible for handling those tasks

Event-Driven Architecture Pattern:

In an event-driven architecture, microservices communicate through asynchronous events. When something significant happens in one microservice, it emits an event, which other microservices can consume and react to. For example, consider a ride-sharing application where there are separate microservices for booking rides, sending notifications, and calculating payment. When a ride is booked, the booking microservice emits an event indicating the booking details, which the notification microservice can consume to send a notification to the driver, and the payment microservice can use to calculate the fare.

Circuit Breaker Pattern:

The circuit breaker pattern is used to handle failures and prevent cascading failures in a distributed system. It wraps calls to remote microservices and monitors their responses. If a microservice fails repeatedly, the circuit breaker can temporarily stop sending requests to that service, thereby avoiding further failures. In a banking application, if a microservice responsible for making payments is consistently failing to respond, the circuit breaker can open and redirect the requests to a backup payment service or display a friendly error message to the user.

Service Registry Pattern:

In this pattern, a central service registry is used to keep track of all the available microservices. Microservices register themselves with the registry, making it easier for other microservices to discover and communicate with them. Imagine a food delivery application where there are multiple microservices responsible for handling different tasks, such as order management, payment processing, and delivery tracking. The service registry acts as a directory, allowing each microservice to find and interact with the required services.

Database per Service Pattern:

In this pattern, each microservice has its own dedicated database. This allows each microservice to manage its data independently, which promotes loose coupling and scalability. For example, consider an e-commerce application where one microservice handles user authentication, while another manages product inventory. Each microservice would have its own separate database to store and retrieve data related to its specific domain.