# WCF Services and Event Tracing for Windows

This sample demonstrates how to use the analytic tracing in Windows Communication Foundation (WCF) to emit events in Event Tracing for Windows (ETW). The analytic traces are events emitted at key points in the WCF stack that allow troubleshooting of WCF services in production environment.

Analytic trace in WCF services is tracing that can be turned on in a production environment with minimal impact on performance. These traces are emitted as events to an ETW session.

This sample includes a basic WCF service in which events are emitted from the service to the event log, which can be viewed using Event Viewer. It is also possible to start a dedicated ETW session that listens for events from the WCF service. The sample includes a script to create a dedicated ETW session that stores events in a binary file that can be read using Event Viewer.

#### To use this sample

1. Using Visual Studio 2012, open the EtwAnalyticTraceSample.sln solution file.

2. To build the solution, press CTRL+SHIFT+B.

3. To run the solution, press CTRL+F5.

In the Web browser, click Calculator.svc. The URI of the WSDL document for the service should appear in the browser. Copy that URI.

By default, the service starts listening for requests on port 1378 http://localhost:1378/Calculator.svc.

4. Run the WCF test client (WcfTestClient.exe).

The WCF test client (WcfTestClient.exe) is located at \<Visual Studio 2012 Install Dir>\Common7\IDE\WcfTestClient.exe. The default Visual Studio 2012 install dir is C:\Program Files\Microsoft Visual Studio 10.0.

5. Within the WCF test client, add the service by selecting File, and then Add Service.

Add the endpoint address in the input box. The default is http://localhost:1378/Calculator.svc.

6. Open the Event Viewer application.

Before invoking the service, start Event Viewer and ensure that the event log is listening for tracking events emitted from the WCF service.

7. From the Start menu, select Administrative Tools, and then Event Viewer. Enable the Analytic and Debug logs.

8. In the tree view in Event Viewer, navigate to Event Viewer, Applications and Services Logs, Microsoft, Windows, and then Application Server-Applications. Right-click Application Server-Applications, select View, and then Show Analytic and Debug Logs.

Ensure that the Show Analytic and Debug Logs option is checked.

9. Enable the Analytic log.

In the tree view in Event Viewer, navigate to Event Viewer, Applications and Services Logs, Microsoft, Windows, and then Application Server-Applications. Right-click Analytic and select Enable Log.

#### To test the service

1. Switch back to WCF test client and double-click Divide and keep the default values, which specify a denominator of 0.

If the denominator is 0, then the service throws a fault.

2. Observe the events emitted from the service.

Switch back to Event Viewer and navigate to Event Viewer, Applications and Services Logs, Microsoft, Windows, and then Application Server-Applications. Right-click Analytic and select Refresh.

The WCF analytic trace events are displayed in the event viewer. Notice that because a fault was thrown by the service an error trace event is displayed in the event viewer.

3. Repeat steps 1 and 2, but with valid inputs. The value of the N2 parameter can be any number other than 0.

Refresh the analytic channel to view the WCF events do not include any error events.

The sample demonstrates the analytic trace events emitted from a WCF service.

#### To cleanup (Optional)

1. Open Event Viewer.

2. Navigate to Event Viewer, Applications and Services Logs, Microsoft, Windows, and then Application-Server-Applications. Right-click Analytic and select Disable Log.

3. Navigate to Event Viewer, Applications and Services Logs, Microsoft, Windows, and then Application-Server-Applications. Right-click Analytic and select Clear Log.

4. Choose the Clear option to clear the events.

Important

The samples may already be installed on your computer. Check for the following (default) directory before continuing.

<InstallDrive>:\WF_WCF_Samples

If this directory does not exist, go to Windows Communication Foundation (WCF) and Windows Workflow Foundation (WF) Samples for .NET Framework 4 to download all Windows Communication Foundation (WCF) and WF samples. This sample is located in the following directory.

<InstallDrive>:\WF_WCF_Samples\WCF\Basic\Management\ETWTracing