ASPNET worker process stop responding when an asynch Process.Start is spawned

Question

In ASPNET Page I need to spawn a Process to do some CPU heavy work (ffmpeg) . I wish:
a) send response to client without wait for process exit
b) to do something when Process is done
If I do:

Process pc = new Process();
pc.EnableRaisingEvents = true;
pc.StartInfo.UseShellExecute = false;
pc.StartInfo.WorkingDirectory = AppDir;
pc.StartInfo.FileName = AppDir + "ffmpeg.exe";
pc.StartInfo.Arguments = ... some strings ...
pc.Exited += new EventHandler(handlerExit);
pc.Start();
// End Page
Response.Flush();
this.Context.ApplicationInstance.CompleteRequest();

void handlerExit(object sender, System.EventArgs e)
    {
            string[] files = Directory.GetFiles(vars["path"] ,vars["filein"] + "*");
            for (int i = 0; i < files.Length; i++)
            {
                File.Delete(files[i]);
            }
    }

the browser correct receive response when ffmpeg is still running, but ASPNET stop to respond to every subsequent requests. When process exit,the ASPNET Worker process start again to respond. I attempted to adjust process priority start option like AboveNormal or Idle but without success. Any ideas to manage this ?

score 1 · Answer 1 · edited May 23 '17 at 12:04

1

This is due to session lock. Disable the session on the page you call that.

Reference:

jQuery Ajax calls to web service seem to be synchronous

Web app blocked while processing another web app on sharing same session

Replacing ASP.Net's session entirely

edited May 23 '17 at 12:04

Community

1
1

answered Jun 28 '12 at 10:13

Aristos

66,005
16
114
150

It seems to me you've catch the right point but adding EnableSessionState="false" directive to the Page that spawn the process isn't enough because wp continue to be blocked. Maybe I've to take a more deep look to ASPNET Session State. – alrama Jun 28 '12 at 12:20
I'm convinced that is not a Session State issue only. – alrama Jul 02 '12 at 09:17
@alrama Yes probably is not only session state issue, the next think is probably open threads that runs your code. – Aristos Jul 02 '12 at 09:37

ASPNET worker process stop responding when an asynch Process.Start is spawned

1 Answers1