HTTP Long Polling
HTTP Long Polling is a technique for achieving real-time communication between a client and server over HTTP, where the client sends a request to the server and the server holds it open until new data is available or a timeout occurs. Once the server responds, the client immediately sends another request to maintain a persistent connection, enabling near-real-time updates without constant polling. It is commonly used in web applications to simulate server push functionality before the advent of WebSockets.
Developers should learn HTTP Long Polling when building real-time features like chat applications, live notifications, or stock tickers in environments where WebSockets are not supported or feasible, such as older browsers or restrictive network configurations. It provides a fallback mechanism for real-time communication, ensuring compatibility and reliability in diverse deployment scenarios, though it may introduce latency and server overhead compared to more modern alternatives.