C# .NET
 

  How to handle multiple requests simultaneously using HttpListeners

Asked By Sachin Mishra
19-Nov-08 02:12 AM
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How to handle multiple requests simultaneously using HttpListeners ? I am working on an application which listen the http request but how will have to implement the multiple request simultaneously processed by the client application at same time.

 

 

  re

Web Star replied to Sachin Mishra
19-Nov-08 02:18 AM
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webservice that will receive/process multiple
client requests simultaneously. For this purpose, I wrote the following
code, but it does not seem to be handling more than two at a time. I
put in a few console prints and have also attached the output. Here it
goes -

public void serverStart() {

   HttpListener _listener = new HttpListener();

   _listener.Prefixes.Add(.......);

   _listener.Start();

   while (true)

       ProcessRequest();

}

public void ProcessRequest()

{

    Console.WriteLine("PR " + ++count); //count initialized to 0 in
beginning

    IAsyncResult result = _listener.BeginGetContext(new AsyncCallback
ListenerCallback),this._listener);

    result.AsyncWaitHandle.WaitOne();

}

protected void ListenerCallback(IAsyncResult result)

{

    if (this._listener == null) return;

    HttpListenerContext context = this._listener.EndGetContext(result);

    Console.WriteLine("LC " + count);

    this.ProcessRequest2(context);

}

public void ProcessRequest2(HttpListenerContext ctx)

{

    Console.WriteLine("PR2 " + count);

    string str = ctx.Request.HttpMethod;

    HttpListenerWorkerRequest workerRequest =

    new HttpListenerWorkerRequest(ctx,_virtualDir, _physicalDir,
_logCallback, _pxeb);

    HttpRuntime.ProcessRequest(workerRequest);

}

  use HttpListener

Web Star replied to Sachin Mishra
19-Nov-08 02:19 AM
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HttpListener allows only one request to be handled concurrently?
using System;
using System.Collections.Generic;
using System.Net;
using System.Threading;
using System.IO;
 
sealed class HttpServer
{
public static void Main()
{
HttpListener listener = new HttpListener();
listener.Prefixes.Add("http://*:" + 1234 + "/");
listener.Start();
for(int i =0; i< 10; i++)
{
IAsyncResult result = listener.BeginGetContext(new AsyncCallback(HttpWorker.Handle), listener);
}
Console.WriteLine("Press ENTER to quit.");
Console.Read();
}
}
public class HttpWorker{
 
public static void Handle(IAsyncResult ar)
{
HttpListener listener = (HttpListener) ar.AsyncState;
try
{
HttpListenerContext context = listener.EndGetContext(ar);
StreamWriter writer = new StreamWriter(context.Response.OutputStream);
writer.Write("<html><body>");
writer.Write("This call was handled in " + Thread.CurrentThread.ManagedThreadId);
Thread.Sleep(5000);
writer.Write("<br>");
writer.Write("Done");
writer.Write("</body></html>");
writer.Close();
context.Response.OutputStream.Close();
context.Response.Close();
}
finally
{
listener.BeginGetContext(new AsyncCallback(HttpWorker.Handle), listener);
}
}
}
 

  Re :: Handle multiple requests simultaneously using HttpListeners

Shailendrasinh Parmar replied to Sachin Mishra
19-Nov-08 02:19 AM
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  read this
C_A P replied to Sachin Mishra
19-Nov-08 02:26 AM
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Ok the question you are asking is a bit tricky.  Deep down httplistener is using IOCompletion ports.  You can easily verify this yourself by placing the following code in your Handle function.

int ioThreads, workerThreads;

System.Threading.ThreadPool.GetAvailableThreads( out workerThreads, out ioThreads );

Console.WriteLine( "IOThreads: " + ioThreads.ToString() + " WorkerThreads: " + workerThreads.ToString() );

System.Threading.ThreadPool.GetMaxThreads( out workerThreads, out ioThreads );

Console.WriteLine( "IOThreadsMax: " + ioThreads.ToString() + " WorkerThreadsMax: " + workerThreads.ToString() );

you should see that the available IO threads are 999 and the max is 1000 which means that your request is coming in on an iothread (if it wasn't you would see the worker threads are 1 less than max), typically you only use 1 io thread per cpu with a 1 overflow so 2 per cpu.  I have no idea what rules the OS uses to decide if needs to use that 1 io thread overflow .  Plus you are using Sleep which may also be causing erroneous behaviour. 

Basically you are placing the sleep there to mimic work am I correct?

Problem is that Thread.Sleep is a very poor example for the system "working" its just not treated the same.  I suggest a different test.  Perhaps using microsofts free load tester and take the sleep out and see how many connections you can handle per second.  That is far better test for a system.  That is unless all you are trying to prove is that two requests on httplistener are happening at the same exact time.
  How to handle multiple requests simultaneously using HttpListeners
Ravi Danum replied to C_A P
20-Nov-09 01:35 PM
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Hello,

I also saw that only two requests could be handled at a time by HttpListener.

To get around this, use the following.  I now have 10 executing at the same time with HttpListener.  The solution involves making a change to the registery.

1. Start the registry editor.

2. Locate the following key in the registry:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings

3. On the Edit menu, point to New, click DWORD Value, and then add the following registry values:

Value name: MaxConnectionsPer1_0Server

Value data: 10

Base: Decimal

Value name: MaxConnectionsPerServer

Value data: 10

Base: Decimal

4. Exit the registry.

 

 

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