Socket.IO vs SocketCluster: What are the differences?

Introduction

In this article, we will explore the key differences between Socket.IO and SocketCluster. Both Socket.IO and SocketCluster are popular frameworks for real-time applications, but they have some distinct differences that set them apart.

1. Scalability: Socket.IO is a library that provides real-time bidirectional communication between clients and servers. It supports multiple transports, including WebSocket, AJAX long polling, and more. However, Socket.IO does not inherently provide scalability features out of the box. On the other hand, SocketCluster is a full-featured, scalable real-time framework built on top of Socket.IO. SocketCluster provides built-in horizontal scalability, allowing you to scale your application across multiple cores or machines effortlessly.

2. Clustering: Socket.IO does not provide built-in clustering capabilities. If you want to cluster your Socket.IO server to handle high traffic loads, you need to implement clustering manually using tools like Node.js cluster module or external load balancers. SocketCluster, as its name suggests, provides built-in clustering functionality. It simplifies the process of setting up and managing clusters, making it easier to handle large numbers of concurrent connections.

3. Authentication: Socket.IO does not have built-in authentication support. If you want to add authentication to your Socket.IO application, you need to implement it yourself. SocketCluster, on the other hand, provides built-in authentication mechanisms. It supports various authentication strategies like JWT (JSON Web Tokens) and OAuth, making it easier to secure your real-time application.

4. Presence Channels: Socket.IO does not provide built-in support for presence channels. Presence channels allow you to track the online status of users in real-time applications. With Socket.IO, you have to implement presence functionality manually. SocketCluster, on the other hand, has built-in support for presence channels. It offers convenient APIs to track the presence of users, making it easier to build real-time applications that require user presence tracking.

5. Pub-Sub Architecture: Socket.IO follows a publish-subscribe (pub-sub) pattern, where clients subscribe to specific events and receive messages when those events are published. However, it does not provide a full pub-sub architecture. SocketCluster, on the other hand, is built on top of the pub-sub model. It provides a powerful pub-sub mechanism that allows you to scale your real-time applications by decoupling publishers and subscribers.

6. Scalable RPC (Remote Procedure Call): SocketCluster provides a scalable RPC mechanism out of the box. With SocketCluster, you can easily define remote procedures on the server and call them from the client using RPC. This simplifies the process of building real-time applications that require remote method invocations. Socket.IO does not provide a built-in RPC mechanism.

In summary, Socket.IO is a versatile library for real-time bidirectional communication but lacks built-in scalability, clustering, authentication, presence channels, a complete pub-sub architecture, and scalable RPC. SocketCluster, on the other hand, is a full-featured real-time framework built on top of Socket.IO that provides these additional features, making it a better choice for applications that require scalability, clustering, authentication, presence tracking, pub-sub architecture, and RPC.