Can a http server detect that a client has cancelled their request?

by

While @Oded is correct that HTTP is stateless between requests, app servers can indeed detect when the underlying TCP/IP connection has broken for the request being processed. Why is this? Because TCP is a stateful protocol for reliable connections.

A common technique for .Net web apps processing a resource intensive request is to check Response.IsClientConnected (docs) before starting the resource intensive work. There is no point in wasting CPU cycles to send an expensive response to a client that isn’t there anymore.

private void Page_Load(object sender, EventArgs e)
{
    // Check whether the browser remains
    // connected to the server.
    if (Response.IsClientConnected)
    {
        // If still connected, do work
        DoWork();
    }
    else
    {
        // If the browser is not connected
        // stop all response processing.
        Response.End();
    }
}

Please reply with your target app server stack so I can provide a more relevant example.

Regarding your 2nd alternative to use XHR to post client page unload events to the server, @Oded’s comment about HTTP being stateless between requests is spot on. This is unlikely to work, especially in a farm with multiple servers.

More Related Contents:

  1. How to idiomatically log auth information with middleware
  2. What is the difference between POST and PUT in HTTP?
  3. How long do browsers cache HTTP 301s?
  4. Correct way to pass multiple values for same parameter name in GET request
  5. What is the difference between HTTP status code 200 (cache) vs status code 304?
  6. HTTP 1.0 vs 1.1
  7. How to set a timeout on a http.request() in Node?
  8. Angular2 http.get() ,map(), subscribe() and observable pattern – basic understanding
  9. What should a Multipart HTTP request with multiple files look like? [duplicate]
  10. Cookie handling in Google Apps Script – How to send cookies in header?
  11. Difference between no-cache and must-revalidate
  12. Correct way of getting Client’s IP Addresses from http.Request
  13. HTTP status code for a partial successful request
  14. How to use angular2 http API for tracking upload/download progress
  15. Why can’t I set a cookie and redirect?
  16. What is the function of the “Vary: Accept” HTTP header?
  17. Why is my Hello World go server getting crushed by ApacheBench?
  18. Doing a HTTP PUT from a browser
  19. angular — accessing data of multiple http calls – how to resolve the promises
  20. How do I create a persistent vs a non-persistent cookie?
  21. Compressing HTTP Post Data sent from browser
  22. RESTful Alternatives to DELETE Request Body
  23. Escaping username characters in basic auth URLs
  24. Can I stream a file upload to S3 without a content-length header?
  25. How to evaluate http response codes from bash/shell script?
  26. HTTP status code for temporarily unavailable pages
  27. How can I start the browser AFTER the server started listening?
  28. Why this simple web server is called even number times?
  29. Service Oriented Architecture – AMQP or HTTP
  30. How to set up CORS or OPTIONS for Rocket.rs

Leave a Comment