ServiceThrottlingBehavior.MaxConcurrentCalls Property

Definition

Namespace:

System.ServiceModel.Description

Assembly:

System.ServiceModel.dll

Gets or sets a value that specifies the maximum number of messages actively processing across a ServiceHost.

public:
 property int MaxConcurrentCalls { int get(); void set(int value); };

public int MaxConcurrentCalls { get; set; }

member this.MaxConcurrentCalls : int with get, set

Public Property MaxConcurrentCalls As Integer

Property Value

Int32

The upper limit of active messages in the service. The default is 16 times the processor count.

Examples

The following code example shows the use of ServiceThrottlingBehavior from an application configuration file that sets the MaxConcurrentSessions, MaxConcurrentCalls, and MaxConcurrentInstances properties to 1 as an example. Real-world experience determines what the optimal settings are for any particular application.

<configuration>
  <appSettings>
    <!-- use appSetting to configure base address provided by host -->
    <add key="baseAddress" value="http://localhost:8080/ServiceMetadata" />
  </appSettings>
  <system.serviceModel>
    <services>
      <service 
        name="Microsoft.WCF.Documentation.SampleService"
        behaviorConfiguration="Throttled" >
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8080/SampleService"/>
          </baseAddresses>
        </host>
        <endpoint
          address=""
          binding="wsHttpBinding"
          contract="Microsoft.WCF.Documentation.ISampleService"
         />
        <endpoint
          address="mex"
          binding="mexHttpBinding"
          contract="IMetadataExchange"
         />
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior  name="Throttled">
          <serviceThrottling 
            maxConcurrentCalls="1" 
            maxConcurrentSessions="1" 
            maxConcurrentInstances="1"
          />
          <serviceMetadata 
            httpGetEnabled="true" 
            httpGetUrl=""
          />
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>
</configuration>

Remarks

The MaxConcurrentCalls property specifies the maximum number of messages actively processing across a ServiceHost object. Each channel can have one pending message that does not count against the value of MaxConcurrentCalls until Windows Communication Foundation (WCF) begins to process it.

You can also set the values of this attribute by using the <serviceThrottling> element in an application configuration file.

Warning

MaxConcurrentCalls should be set to less than the SQL connection pool size in queued scenarios.