Microservices architecture is gaining popularity due to its ability to build scalable and resilient systems by breaking down large monolithic applications into smaller, loosely coupled services. However, as the number of microservices grows, managing the shared state across these services can become challenging.

Immer is a popular JavaScript library that helps simplify state management by allowing us to work with immutable data structures in a more convenient and efficient manner. In this blog post, we will explore how we can leverage Immer in a microservices architecture to handle shared state effectively.

What is Immer?

Immer is a library that provides an easy and intuitive way to produce and work with immutable data structures in JavaScript. It allows us to create a draft of the current state, apply modifications to it in a mutable way, and then produce a new immutable state tree with the changes.

Benefits of Using Immer in a Microservices Architecture

Simplicity and Clarity

One of the biggest challenges in managing shared state across microservices is dealing with the complexity introduced by mutable data structures. By using Immer, we can write clean, declarative code without worrying about accidental mutations. Immer takes care of making the necessary copies behind the scenes to ensure the immutability of the state.

Performance

Immer utilizes a concept called “structural sharing”, where it only creates copies of the modified portions of the state. This approach ensures that only the modified parts are copied, leading to improved performance compared to deep copying entire data structures. With Immer, we can achieve immutability without sacrificing performance in our microservices.

Example Usage of Immer in a Microservices Architecture

Let’s consider a scenario where we have two microservices, User Management and Email Notifications. The User Management service is responsible for managing user data, while the Email Notifications service sends notifications to users.

Here’s an example of how we can use Immer to manage the shared user state across these services:

import produce from 'immer';

// User Management Service
const userState = {
  users: []
};

export function addUser(user) {
  produce(userState, draftState => {
    draftState.users.push(user);
  });
}

// Email Notifications Service
export function sendWelcomeEmail(user) {
  // Fetch user data from User Management Service
  const userData = fetchUserData(user.id);

  // Send email using the user data
  ...
}

In the example above, the User Management service uses Immer’s produce function to add a new user to the userState object. Immer ensures that the userState remains immutable and returns a new state object with the updated user list.

The Email Notifications service can then fetch the user data from the User Management service using the user’s ID and send a welcome email. By using Immer, we can avoid accidental mutations and work with immutable user data.

Conclusion

Immer is a powerful library for managing shared state in a microservices architecture. By leveraging its simplicity, clarity, and performance benefits, we can write robust and maintainable code. With Immer, we can handle shared state across microservices efficiently, making our microservices architecture more scalable and resilient.

#techblog #microservices #Immer