AppFabric’s E2EActivityId and non .Net 4.0 clients

Recently came across the scenario where the client wanted to supply the ActivityId that is to be used in AppFabric, however they weren't a .Net 4.0 client. If the client supplied the ActivityId in SOAP header request, then the framework will use this, rather than creating its own (assuming the monitoring level is End-To-End).

For .Net 4.0 clients, it's very easy to specify the value at the client end using Trace.CorrelationManager.ActivityId and ensuring that <endToEndTracing propagateActivity="true"/> is set in the client config. However endToEndTracing is new to .Net 4.0.

Initially I tried: OperationContext.Current.OutgoingMessageHeaders.Add(MessageHeader.CreateHeader("ActivityId", "http://schemas.microsoft.com/2004/09/ServiceModel/Diagnostics", activityId.ToString()))

where activityId was my guid in the client, however the ActivityId type also has a correlation id property, which is an attribute in XML. And that's the problem, I'm not aware of a method of adding a SOAP header element where you want to set a custom attribute on the element. The framework will ignore the ActivityId header if no correlation id is supplied as well.

So the option I went with was modifying the MessageContract to include the ActivityId header, so when you create the request at the client, you have the option of setting the Activity and Correlation Id. Here is the ActivityId type:

[System.Xml.Serialization.XmlTypeAttribute(Namespace = "http://schemas.microsoft.com/2004/09/ServiceModel/Diagnostics")]

[System.Xml.Serialization.XmlRootAttribute(Namespace = "http://schemas.microsoft.com/2004/09/ServiceModel/Diagnostics", IsNullable = false)]

public class ActivityId

{

[System.Xml.Serialization.XmlAttributeAttribute()]

public Guid CorrelationId;

[System.Xml.Serialization.XmlTextAttribute()]

public Guid Value;

}

Next, add a property of this type to the request message contract:

        [System.ServiceModel.MessageHeaderAttribute(Namespace = "http://schemas.microsoft.com/2004/09/ServiceModel/Diagnostics")]



       public ActivityId ActivityId;

Done. FYI – the schema definition for the ActivityId type is available here http://msdn.microsoft.com/en-us/library/cc485806(PROT.10).aspx