WebSocket

What is WebSocket?

WebSockets is a protocol for bi-directional, real-time communication between a client and a server. It allows for low-latency communication between the two endpoints, as well as reduced overhead compared to traditional HTTP communication. WebSockets are commonly used for real-time applications such as online gaming, chat, and live data updates. The WebSocket protocol is based on TCP and uses a handshake to establish a connection between the client and server, after which point the connection remains open and messages can be sent back and forth in real-time. The WebSocket API is implemented in JavaScript and is available in most modern web browsers.

How it works?

WebSockets work by first establishing a connection between the client and server using the HTTP protocol. The client sends an HTTP request to the server with an “Upgrade” header, asking to upgrade the connection to a WebSocket connection. The server then sends back an HTTP response with a “101 Switching Protocols” status code to confirm that the connection has been upgraded.

Once the connection is established, the client and server can send messages back and forth in real-time without the need for additional handshakes. The WebSocket protocol uses a simple frame-based format for sending and receiving messages, which allows for low-latency communication.

source: internet, Working of WebSocket

On the client side, the WebSocket API provides an interface for connecting to a WebSocket server, sending and receiving messages, and handling connection events such as open, message, error, and close. On the server side, WebSocket libraries and frameworks provide a simple API for working with WebSocket connections and handling incoming messages.

It’s worth noting that WebSockets are a full-duplex protocol, meaning that both the client and the server can send messages at the same time, without waiting for the other side to finish sending. This allows for real-time and interactive communication.

How Low-latency?

1. Reduced Overhead: Once the WebSocket connection is established, the client and server can send messages back and forth without the need for additional handshakes or setup. This reduces the overhead compared to the traditional HTTP communication, where a new connection must be established for each request and response.
2. Full-Duplex Communication: WebSockets are a full-duplex protocol, meaning that both the client and the server can send messages at the same time, without waiting for the other side to finish sending. This allows for real-time and interactive communication, where a message can be sent and received right away.
3. Low-Level Protocol: WebSockets use a simple frame-based format for sending and receiving messages, which allows for low-latency communication. This format is more efficient than the text-based format used by HTTP.
4. Keep-Alive: WebSockets connection stays open and it can be used for multiple message exchanges between client and server. This eliminates the need for the time-consuming process of opening and closing the connection for every message exchange.

WebSocket Security

WebSockets do not provide built-in security mechanisms, so it is important to take steps to secure WebSocket connections. Here are a few ways to enhance the security of WebSockets:

1. Secure WebSockets (wss://): WebSockets use the ws:// protocol, but you can use the secure version wss:// to encrypt the communication. This is done by using the Secure Sockets Layer (SSL) or Transport Layer Security (TLS) protocols to establish an encrypted connection.
2. Authentication and Authorization: It is important to implement proper authentication and authorization to ensure that only authorized users can access the WebSocket server. This can be done by requiring a valid token or credentials for each WebSocket connection.
3. Firewall: A firewall can be used to limit the incoming traffic to the WebSocket server and block any unauthorized incoming connection.
4. Input validation: WebSockets are susceptible to the same types of attacks as other web technologies, such as cross-site scripting (XSS) and injection attacks. It is important to validate all input and sanitize any data received from the client to protect against these types of attacks.
5. Regular update: Keep all the software, libraries and framework up to date with the latest security patches to ensure that any known vulnerabilities are addressed.

It is important to note that the security of WebSockets depends on the overall security of the system in which they are used and that securing WebSockets alone may not be enough to secure the entire application.

Scalability

Scalability is an important aspect to consider when using WebSockets in a production environment. As the number of connected clients increases, the server may become overwhelmed and unable to handle the increased load. Here are a few ways to address scalability issues with WebSockets:

1. Load balancing: Load balancing can be used to distribute the load among multiple servers. This allows the system to handle a larger number of clients and reduces the risk of a single server becoming overwhelmed.
2. Horizontal scaling: Horizontal scaling involves adding more servers to the system as needed. This allows the system to handle a larger number of clients by increasing the available resources.
3. Caching: Caching can be used to reduce the load on the server by storing frequently-used data on the client side.
4. Stateless design: By maintaining a stateless design, it is possible to route WebSocket connections to different servers, allowing for horizontal scaling and more efficient load balancing.
5. Monitoring: Regular monitoring of the system can help to identify bottlenecks and potential scalability issues early on.

It is important to note that the scalability of a WebSocket-based system depends on the overall architecture and design of the system.

Use Case

WebSockets are used for real-time, low-latency communication between a client and server. Here are a few common use cases for WebSockets:

1. Real-time chat and messaging: WebSockets are commonly used to build real-time chat and messaging applications. They allow for low-latency communication between users, making the chat experience feel more immediate and responsive.
2. Multiplayer games: WebSockets are well-suited for building multiplayer games, as they allow for real-time communication between players. This allows for fast and responsive gameplay, which is especially important in fast-paced games.
3. Live data updates: WebSockets can be used to push live data updates to clients in real-time. This is particularly useful for applications such as stock tickers, sports scores, and weather updates.
4. Internet of Things: WebSockets can be used for communication between IoT devices and a server. The low-latency and real-time nature of WebSockets make them well-suited for use cases such as remote device control, sensor data collection, and real-time monitoring.
5. Collaborative tools: WebSockets are a great fit for tools that require real-time collaboration, like online documents, project management tools, and team collaboration platforms.
6. Financial trading: WebSockets can be used to provide low-latency communication between a trading platform and its clients, allowing for faster and more accurate trade execution.

These are just a few examples of the many ways that WebSockets can be used. The real-time and low-latency communication provided by WebSockets make them well-suited for a wide variety of use cases.

Cons

1. Lack of built-in security: WebSockets do not provide built-in security mechanisms, so it is important to take steps to secure WebSocket connections.
2. Limited browser support: WebSockets are not supported by all web browsers, so it may not be possible to use them in certain cases.
3. Scalability: As the number of connected clients increases, the server may become overwhelmed and unable to handle the increased load. It is important to consider scalability when using WebSockets in a production environment.
4. Complexity: WebSockets requires an additional layer of complexity as it is not a simple request-response protocol like HTTP.

In summary, WebSockets provide a powerful way to implement real-time, low-latency communication between a web client and server. They can be used for a variety of applications and are supported by most modern web browsers. However, it is important to consider security and scalability when implementing WebSockets in a production environment.

Look chat app example: here