Throttling

    WCF throttling provides some properties that you can use to limit how many instances or sessions are created at the application level. Performance of the WCF service can be improved by creating proper instance.

Attribute	Description
maxConcurrentCalls	Limits the total number of calls that can currently be in progress across all service instances. The default is 16.
maxConcurrentInstances	The number of InstanceContext objects that execute at one time across a ServiceHost. The default is Int32.Max Value.
maxConcurrentSessions	A positive integer that limits the number of sessions a ServiceHost object can accept. The default is 10.

  

Administrative (configuration file)

    

     Using <service Throttling> tag of the Service Behavior, you can configure the maxConcurrentCalls, maxConcurrentInstances, maxConcurrentSessions property as shown below.

<system.serviceModel>

    <services >

      <service behaviorConfiguration="ServiceBehavior"  name="MyService">

        <endpoint address="" binding="wsHttpBinding" contract="IMyService">

          <identity>

            <dns value="localhost"/>

          </identity>

        </endpoint>

        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>

      </service>

    </services>

    <behaviors>

      <service Behaviors>

        <behavior name="ServiceBehavior">

          <service Metadata httpGetEnabled="true"/>

          <serviceDebug includeExceptionDetailInFaults="true "/>

          <service Throttling maxConcurrentCalls="500"

 maxConcurrentInstances ="100"

maxConcurrentSessions ="200"/>

        </behavior>

      </service Behaviors>

    </behaviors>

  </system.serviceModel>

Programming Model

Use ServiceThrottlingBehavior object to set concurrent calls, session and instance property.

Service Host host = new Service Host (typeof (MyService));

ServiceThrottlingBehavior throttle = host.Description.Behaviors.Find ();

If (throttle == null)

  {

     Throttle = new ServiceThrottlingBehavior ();

     throttle.MaxConcurrentCalls = 500;

     throttle.MaxConcurrentSessions = 200;

     throttle.MaxConcurrentInstances = 100;

     host.Description.Behaviors.Add (throttle);

   }

host.Open ();