How to set keep alive interval for HTTP connection in WCF

Question

Http transport channel in WCF uses persistent HTTP connections by default. How to control keep alive timeout for those connections? Default value is 100s. I found that value by monitoring application in Procmon. I haven't found any setting in http transport binding element which configures this timeout. Is there any .NET class which can control that timeout?

Answer 1

Take a look here: http://blog.magenic.com/blogs/jons/archive/2007/05/04/The-Tao-of-Microsoft-WCF-CustomBinding-Configuration-Elements.aspx

There is a detailed discussion of manipulating the keep alive property during an http connection.

Answer 2

From this answer, and what I can read here, it looks like you want to create a custom http binding, and set the inactivityTimeout attribute.

From the MSDN article:

<bindings>
  <customBinding>
    <binding name="Binding1">
      <reliableSession acknowledgementInterval="00:00:00.2000000" enableFlowControl="true"
                        maxTransferWindowSize="32" inactivityTimeout="00:10:00" maxPendingChannels="128"
                        maxRetryCount="8" ordered="true" />
      <security mode="None"/>
      <httpTransport authenticationScheme="Anonymous" bypassProxyOnLocal="false"
                    hostNameComparisonMode="StrongWildcard" 
                    proxyAuthenticationScheme="Anonymous" realm="" 
                    useDefaultWebProxy="true" />
    </binding>
  </customBinding>
</bindings>

Answer 3

How about this? Seems it may be a function of your IIS Server and nothing to do with the WCF service? I know this link applies to IIS6, but maybe it serves as a foundation to something similar in IIS7? http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/73566f83-c257-4941-8ed8-7ae45b2e7985.mspx?mfr=true

Answer 4

It sounds to me like you're wanting to adjust the Keep-Alive HTTP header. You should read this article on HTTP keep-alive and first determine if this is really something worth your time.

If it is, try creating a Message Inspector. This should allow you to modify the HTTP headers for each message that gets sent out:

public class KeepAliveMessageInspector : IClientMessageInspector
{
    // ...

    public object BeforeSendRequest(
        ref System.ServiceModel.Channels.Message request,
        System.ServiceModel.IClientChannel channel)
    {
        // Add/modify the Keep-Alive header
        var httpRequestMessage = new HttpRequestMessageProperty();
        httpRequestMessage.Headers.Add("Keep-Alive", "9000");
        request.Properties.Add(
            HttpRequestMessageProperty.Name, httpRequestMessage);
        return null;
    }

    // ...
}