Source Listeners
Once you have configured the Configuration Listeners <listeners/> indicating what information is being being tracked, as a child element of <loggingConfiguration/>, you still must specify where the Logging Application Block will output the information, such as a file location or an Event Log, by specifying the Source Listeners. Source Listeners indicate which of the available Configuration Listeners are actually output by the Service.
For example, in the default installation for a Task Service, the Source Listeners are:
<specialSources>
<allEvents switchValue="All" name="All Events">
<listeners>
<add name="Bluespring.TaskService.Console"/>
<add name="Bluespring.TaskService.EventLog"/>
<add name="Bluespring.TaskService.LogFile"/>
</listeners>
</allEvents>
<notProcessed switchValue="All" name="Unprocessed Category"/>
<errors switchValue="All" name="Logging Errors & Warnings"/>
</specialSources>
Notice that, by default, the Task Service specifies the availability of three Configuration Listeners: the Console, the Event Log and the Log File. Each of these three available outputs corresponds to the value of the name attribute for a Configuration Listener defined in the <listeners/>.
Note: Bluespring does not recommend making any changes to the Console.
So, the Source Listener completes the configuration of the logging information. The Configuration Listener defines what information is being tracked, the formatter associated with the information and the behavior of the listener's output (as a file or as an Event Log). The formmater defines the way information tracked by a listener will be displayed. And the Source Listener defines which listeners are output, or not, by the Service.
