Interviewer - Server > Configuration and customization > Increasing the speed of telephone interviews
 
Increasing the speed of telephone interviews
Each virtual directory on your Web server has a queue that stores requests to be passed from IIS to the .NET Framework (ASP.NET). If an application's queue becomes full, users see the HTTP 503, Server is busy, message and the queue starts to rejects requests. If your site uses telephone interviewing, you should consider increasing the queue size to prevent the Phone activity flooding its queue with requests. This change is strongly recommended, especially if you have many interviewers working at the same time.
1 On each computer running the Web Service, navigate to:
For x86 ASP.NET versions:
C:\Windows\Microsoft.Net\Framework\<version>\CONFIG
For x64-bit ASP.NET versions:
C:\Windows\Microsoft.Net\Framework64\<version>\CONFIG
2 Open machine.config.
3 Locate the line that starts <httpRuntime ...> (it is near the beginning of the file) and change the value of the appRequestQueueLimit attribute to a value between 1000 and 5000 (the default setting is 5000).
If the <httpRuntime ...> section does not exist, you must manually create the section with at least the following settings (the values represent the default settings):
<httpRuntime
  minFreeThreads="8"
  minLocalRequestFreeThreads="4"
  appRequestQueueLimit="5000"
/>
4 In the <system.web> section, add the following settings or edit your existing settings so that they contain the designated properties and values.
<system.web>
  <httpRuntime minFreeThreads="88" minLocalRequestFreeThreads="76" appRequestQueueLimit="5000"/>
  <processModel autoConfig="false" maxWorkerThreads="200" maxIoThreads="200"/>
  <httpHandlers/>
  ...
</system.web>
5 Save your changes and close the file.
For more detailed information about this change, refer to pages 818 and 819 of:
http://download.microsoft.com/download/a/7/e/a7ea6fd9-2f56-439e-a8de-024c968f26d1/ScaleNet.pdf
See also
Configuration and customization