Microservice Communication: A Complete Guide 2023

If you are considering developing a web application using Microservice architecture, you're on the right track to building a robust and scalable system. In this guide, we'll explore the key ways microservices communicate with each other. By using the communication approach, you can benefit from improved flexibility, maintainability, and fault tolerance in your development process.

What are microservices?

Microservices are a modern architectural approach to developing applications by breaking them down into small, independent services that can be developed, deployed, and scaled independently. Each microservice is designed to perform a specific business function and communicates with other services through well-defined APIs. 

Advantages of Microservices Architecture

• Scalability and Flexibility:

Microservices allow applications to scale specific services independently based on demand. This modular approach enables developers to add or modify features without affecting the entire application, making it highly adaptable to changing requirements.

• Improved Maintainability:

With each service being separate, the codebase becomes more manageable, making it easier to understand, update, and debug. Teams can work on individual services simultaneously, promoting faster development and deployment.

• Fault Isolation and Resilience:

In a Microservices architecture, if one service fails, it doesn't bring down the entire system. Services are isolated, ensuring that failures are contained and the application remains resilient.

• Technology Diversity:

Microservices allow for the use of different technologies for different services, enabling developers to choose the best tools for each task. This flexibility encourages innovation and allows leveraging the most suitable technology stacks.

• Continuous Deployment:

Microservices promote continuous integration and continuous deployment (CI/CD) practices. Small, independent services can be deployed quickly, reducing the time to market for new features and updates.

What are the 4 ways in which microservices communicate?

Microservices have become increasingly popular due to their ability to improve scalability, maintainability, and overall development agility. One of the key factors that enable microservices to function effectively is their communication mechanism. Let's explore the four ways in which microservices communicate:

• Communication with Clients through RESTful APIs:

Microservices interact with clients through ‘RESTful APIs,’ providing a standardized and platform-independent approach. Clients can make HTTP requests to specific endpoints exposed by microservices to retrieve the required data or perform actions. 

Read our blog: Why Your Enterprise Applications Need A Microservice Architecture?

This decoupled communication enables smooth integration with various client applications.

• Communication between Microservices:

For complex business processes, microservices often need to communicate with each other. This inter-service communication can be achieved through various protocols, such as ‘HTTP,’ ‘gRPC,’ or message queues like ‘RabbitMQ.’ By communicating directly, microservices can collaborate adeptly to provide a cohesive application experience.

• Communication with Data Stores:

Microservices typically have their own databases or data stores. For data consistency, microservices communicate with their respective data stores when they need to read or write data. This approach ensures that each service can manage its data independently without interfering with other services.

• Communication with Infrastructure:

Microservices rely on infrastructure components like service discovery, load balancers, and ‘API gateways.’ Service discovery helps in locating and connecting with other microservices dynamically. Load balancers distribute incoming requests across multiple instances of a service to achieve high availability and scalability. API gateways act as intermediaries between clients and microservices, handling tasks like authentication, rate limiting, and caching.

Microservices Communication Types

When developing a web application using Microservice architecture, understanding the different types of communication between microservices is crucial for a successful implementation. Let's explore two essential types of microservices communication:

• Synchronous Microservices Communication:

In synchronous communication, the client sends a request to a microservice and waits for a response before proceeding. This type of communication is akin to a traditional client-server model. ‘RESTful APIs’ are commonly used for synchronous communication, where the client makes an HTTP request to the microservice, which then processes the request and sends back a response. While this approach simplifies development, it can lead to performance bottlenecks and potential cascading failures if a microservice experiences downtime.

• Asynchronous Microservices Communication:

Asynchronous communication, on the other hand, allows the client to send a message to a microservice without waiting for an immediate response. Instead, the microservice processes the message and sends a response later, or it may not send a response at all, depending on the situation. Asynchronous communication is often achieved through message brokers like ‘RabbitMQ or Kafka.’ This approach improves system resilience, as services can continue to function independently, even if one or more services are temporarily unavailable. However, it introduces complexities in handling eventual consistency and message processing.

Read our blog: What is The Role of Microservices in DevOps: Better Together

How do Microservices Communicate?

Microservices architecture fosters effective communication between individual services, enabling seamless collaboration and improved scalability. Three primary communication methods employed by microservices are:

1. HTTP Communication:

Microservices often communicate through the HTTP protocol, which allows them to interact with each other using standard HTTP methods like ‘GET, POST, PUT, and DELETE.’ This ‘RESTful API’ communication ensures decoupled services and platform independence. HTTP-based communication is well-suited for request-response scenarios and synchronous interactions.

2. Message Communication:

Message-based communication involves the use of message brokers or queues to enable asynchronous interactions between microservices. This method ensures loose coupling, fault tolerance, and scalability. Services can send messages to queues, and other services can consume these messages at their own pace, facilitating better resilience in distributed systems.

Checkout the Guide on Microservices Testing

3. Event-Driven Communication:

In event-driven communication, microservices emit events when certain actions occur. Other services can subscribe to these events and respond accordingly. This pattern allows services to be loosely coupled and react to changes in the system in real time. Event-driven communication is valuable for implementing event sourcing and event-driven architectures.

Summary

By adopting Microservices architecture, your web application development process can be revolutionized and will be cost-effective. Microservices communicate effectively through ‘RESTful APIs,’ with each other, data stores, and various infrastructure components. This approach improves scalability, maintainability, and fault tolerance. With SayOne Tech's expertise in Microservices development, you can unlock the full potential of this architecture for your business. 

Contact SayOne Tech developers today for top-notch Microservices development services.