Long Polling

Long polling is a communication pattern where a client (like a web browser or mobile app) requests data, and the server intentionally delays the response until new information is available.

Core Mechanism

• The client initiates an HTTP request asking for updates.
• Server behavior:
  • Has data ready: Responds back to the client right away.
  • No data ready: Suspends the response, keeping the HTTP connection alive.
  • Once new data is generated, the server completes the response.
  • Upon receiving the response, the client instantly opens a new long-polling request to wait for the next update.