Architecture
Log4Net (http://log4net.sourceforge.net) is a cross-platform, exception-aware application logging framework that has a very simple API for ease of use, but it is complex enough to work in even the largest enterprise applications. A great amount of functionality is available in Log4Net, but to get the system up and logging, there are only five objects needed from Log4Net: Loggers, Appenders, Layouts, Levels, and Filters. Figure 8-1 on p. 194 is a very simplistic flowchart of Log4Net.
Figure 8-1. Flowchart of Log4Net.

TIP
One of the most powerful features of Log4NET that will be covered later in the chapter is its ability to be configured using an XML configuration file as the program is executing.