Introduction: Tracing in .NET Framework
4.0 and how it is used in WCF Services.
In this article, we will look at how we can
trace and debug information in WCF
services.Windows Communication Foundation (WCF) provides application
instrumentation and diagnostic data for fault monitoring and analysis. Instead
of using debugger, You can use tracing to understand how an application is
behaving,
WCF Tracing can track all the events or only
specified events in the program. Tracing is built upon the System.Diagnostics
namespace of the .NET Framework.
WCF outputs the following data for
diagnostic tracing:
- Traces for process milestones across all
components of the applications, such as operation calls, code exceptions,
warnings and other significant processing events."
- Windows error events when the tracing
feature malfunctions.
The important thing about tracing is:-
It is turned off by default, so it needs to be
enable for starting tracing.
There are two ways to enable tracing. These
are followings:-
- One is through code.
- Second is, through config file.
Enabling tracing in config file is good method
since we can easily turn it on and off as required. When debugging is no
longer required we should turn tracing enable off.
Enabling Tracing :
The following code will enable tracing through configuration file:
<system.diagnostics>
<trace
autoflush="true"
/>
<sources>
<source
name="System.ServiceModel"
switchValue="All">
<listeners>
<add
name="TraceListeners"
type="System.Diagnostics.XmlWriterTraceListener"
initializeData=
"c:\Log\trace.svclog"/>
</listeners>
</source>
</sources>
</system.diagnostics>
Tracing Levels:
The tracing levels are controlled by the
switchValue settings. The tracing levels are followings:-
|
Tracing Level |
Description |
| Off |
Ignore all trace messages |
|
Critical |
Log unexpected processing events or
unhandled exceptions have occurred. The application will terminate
immediately or shortly. |
| Error |
An unexpected processing event or
exception has occurred. The application was not able to perform a task
as expected. |
|
Warnings |
Indicates there is a possible problem
but the application will functioning correctly. |
|
Information |
Application is running smoothly only
that informative message is recorded. In this case, messages are just
milestones. |
| Verbose |
Very similar to information but
provides more details as compared. |
|
ActivityTracing |
In this case, messages are related to
communication between components and the activities. |
| All |
In this case, all messages are
captured. |