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Microservices Communication: The Main Types

Application architecture has grown in complexity, with services communicating consistently between each other. Microservice communication is integral for applications, but each call adds a slight bit of latency.

Developers must learn about the main types of microservices communication, starting with communication types.

2 Basic Communication Types: Synchronous vs. Asynchronous

Microservices communications have two basic forms that every developer must know:

  1. Synchronous
  2. Asynchronous

1. Synchronous Communication

When considering synchronous communications, you can think of HTTP. The protocol powers the Internet, and it is invoked when a client sends in a request. For example, a request is sent to the HTTP protocol, and the client waits for a response from the HTTP server.

2. Asynchronous Communication

Asynchronous communication is when the client doesn’t wait for a response back to continue through its processes. AMQP is a prime example of asynchronous communication because a message is sent and added to a queue. Multiple messages may be added before a response is obtained.

Learning these basic communication types is essential before diving deeper into the additional axis available. Besides, the optimization of .net core communication between microservices helps keep the applications running efficiently.

If you’re sending messages, there also must be a receiver. Two main types of receivers also exist:

  1. Single: With a single axis, the receiver must process each request independently.
  2. Many: Multiple receivers, or none, can process each request. A common choice is an event-bus interface where there may be updates sent back by the receiver.

When you create a microservice application, you’ll likely use a mixture of synchronous and asynchronous communication as well as single and multiple receivers. The communication style that you use is based on the application being created.

Developers often choose the best communication style for the job.

Microservice Communication Styles

Developers have to use the right technology to meet their product or service goals. You may need to use one style for one feature and another style for another feature. Since there are multiple protocols and options to choose from, it has led to styles being developed.

A few examples of this may include:

HTTP and REST Protocols

Two of the most common protocols that power many online apps are HTTP and REST. Both of these protocols use asynchronous communications because a request is sent to the server and awaits a response before doing anything else.

When a response is given, the client application will then take an “if-this” approach.

For example, if the response is an error code, the application will show an error or try the request again for an adequate response, depending on the internal logic.

AMQP a WCG/TCP

Internal communications may be made by TCP or WCG, which are common when using a Docker host. Microservice clusters will often use internal communications between microservices using what is considered a “non-standard” binary approach.

Which Communication Method is Best?

Unfortunately, there’s no wrong or correct answer. Some forms of communication are situational, and the answer is genuinely dependent on the rest of the application. Standard and non-standard binary approaches are often combined into one microservice application.

When using the messaging inside an app, it’s common to use asynchronous communication to maintain communication among the different services available.

Why Microservice Architecture is Chosen

Microservice-based applications are rising in popularity as developers try to meet the demands of today’s intense development market. Many applications are hitting the market, and when the app’s features are coupled together too tightly, it leaves little room for error.

Instead, microservices add multiple services together to meet the goal of the app.

When breaking one larger app into microservices, you’re doing this with the idea that each service is:

  • Easily tested and maintained independently to find issues more quickly and deploy patches that impact one service rather than multiple services.
  • Loosely coupled so that services can easily be added or removed as necessary. You can, in many cases, swap services and reuse them in other applications that are under development rather than “recreating the wheel.”
  • Independent services can be deployed without dependencies, making it easier to single out a service for further development.

From a developer standpoint, the microservice architecture that is becoming more popular makes it easy to build and maintain applications. Since multiple services are used, the problems that the software solves can be neatly organized into services.

Teams can focus on each of their respective microservices, allowing for less confusion when coding and back-and-forth with other development teams.

A microservice architecture promotes working in independent teams, which further allows teams to be spread across the world. The idea of a microservice architecture is a solid one because it allows for development freedom without the complexities of other architectures.

The one main concern is communication among all of the services to keep the services working neatly together.

While we’ve mentioned multiple types of communication, they all have their pros and cons or best use cases. For example:

  • HTTP communication is an ideal option for service-to-service communication.
  • Message communication, which listens for messages and doesn’t include direct communication between services.
  • Event-driven communication is asynchronous, and a series of events may be triggered along the way to make sure that the communication remains consistent.

With all applications, communication also means monitoring for slow or failed network requests. Communication issues can derail a microservice, so it’s essential to consider all microservice communications when building out the service.

Summary

Asynchronous and synchronous communication patterns are easy to learn and hard to master. Each communication type has its pros and cons, but they’re vital when working with microservice communication.

Coupling considerations always need to be considered when joining microservices together, and communication will always be complex.

Once you have the communication methods and services in place, it will be much easier to maintain and expand the application using a microservice approach. You may even want to implement a logging system to properly trace all communication to ensure proper responses are given.