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WebSocket

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WebSocket is a communication protocol that allows full-duplex communication, meaning it allows simultaneous data flow in both direction at the same time. WebSocket establish a persistent connection over a single TCP connection, it doesn't need to make request to server like HTTP everytime it want to send new data. WebSocket is suited for real-time communication that needs frequent update such as live dashboard or chat application.

WebSocket is an alternative to pooling for real-time communication. Using pooling means we need to make request periodically to check for new data, this can be wasteful if the application is real-time meaning an update happens often.

WebSocket has different use case with Webhook. WebSocket is typically used for client-server communication such as interactive communication in a chat app. Webhook, on the other hand, typically used for server-server communication or to integrate systems. The use case can be data sync between different system or notify external server.

WebSocket Process​

  1. Handshake: The WebSocket process begins with a handshake between the client and the server. The client sends an HTTP request to the server with WebSocket version included to initiate a communication using WebSocket. If the server supports WebSocket, it responds with an HTTP 101 status code indicating the switch to the WebSocket protocol from HTTP protocol.

  2. Data Exchange & Events: After connection is established, both the client and the server can start sending data to each other in real-time. Client or server may receive events or callbacks such as connection open, message received, error, and connection close events.

  3. Connection Termination: When the client or the server decides to close the WebSocket connection, a close message is exchanged, indicating the intention to terminate the connection. Once both sides have acknowledged the close message, the connection is closed, and the WebSocket session ends.

Websocket process
Source: https://www.wallarm.com/what/a-simple-explanation-of-what-a-websocket-is