Asynchronous support for ASP.NET MVC

Here's the comparison between an async action and a sync action.

Pre-requirements:

• Windows Server 2003 or 2008 with ASP.NET enabled (you cannot use Vista or XP since the limitation of connection number in IIS).
• Visual Studio 2008
• .NET framework 3.5 installed
• Powershell, tinyget in IIS 6.0 Resource Kit Tools and perfmon.

Step 1: Download the sample site with the source code.

Step 2: The HomeController contains an async action and a sync action, you can find them in the sample site (samples/SampleSite) released with the source code.

[AsyncAction]
public ActionResult AsyncAction(AsyncCallback asyncCallback, [AsyncState]object asyncState)
{
    SqlConnection conn = new SqlConnection("...;Asynchronous Processing=true");
    SqlCommand cmd = new SqlCommand("WAITFOR DELAY '00:00:03';", conn);
    conn.Open();
    
    return this.Async(
        cmd.BeginExecuteNonQuery(asyncCallback, asyncState),
        (ar) =>
        {
            int value = cmd.EndExecuteNonQuery(ar);
            conn.Close();
            return this.View();
        });
}
 
public ActionResult SyncAction()
{
    using (SqlConnection conn = new SqlConnection("...;Integrated Security=True"))
    {
        SqlCommand cmd = new SqlCommand("WAITFOR DELAY '00:00:03';", conn);
        conn.Open();
 
        int value = cmd.ExecuteNonQuery();
    }
 
    return this.View();
}

Step 3: Configure the sample site in the IIS of you local system. Make sure that you can visit the home page in http://localhost:7788/Home/Index.

Step 4: Increase the min thread number in the thread pool by executing the following code in the web site (you can build your own handler to do so):

ThreadPool.SetMinThreads(10, 10);

Step 5: Start perfmon and monitor the counter: ASP.NET Applications/Requests Executing

Step 6: Open the Powershell command prompt, execute the following scripts (it can be found in the samples/Benchmarks/Scripts.ps1):

Measure-Command {.\tinyget -srv:localhost -r:7788 -uri:/Home/SyncAction -threads:30 -loop:1}
[System.Threading.Thread]::Sleep(2000)
Measure-Command {.\tinyget -srv:localhost -r:7788 -uri:/Home/AsyncAction -threads:30 -loop:1}
[System.Threading.Thread]::Sleep(2000)
Measure-Command {.\tinyget -srv:localhost -r:7788 -uri:/Home/AsyncAction -threads:40 -loop:1}
[System.Threading.Thread]::Sleep(2000)
Measure-Command {.\tinyget -srv:localhost -r:7788 -uri:/Home/AsyncAction -threads:50 -loop:1}

Result:

Max Request Executing	Execution Time (s)
6	15.06
30	3.10
40	3.11
50	3.10

Snapshot of perfmon: