Logging in .NET

The .NET API produces logging information. The logging facility uses NLog.

NLog is included in the .NET client assembly. For more information about logging with NLog, see https://github.com/NLog/NLog/wiki/.

Logging basics

The NLog Logger class acts as the source of the log messages. In general, use one logger per class and pass in the name of the class as the logger name.

To log a message at a certain level use the write methods provided by the Logger class.

The following log levels are provided:

Fatal
Error
Warn
Info
Debug
Trace

These levels are listed in order from most severe to least severe.

Configuring the log output

You must configure NLog to output the log messages produced by your application to a target or targets. NLog provides a large number of targets for your output, including File and Console. NLog also enables you to create your own targets.

In addition to specifying targets for the log output, use NLog configuration to define rules that specify to which target log messages with particular levels or logger names are directed.

You can configure NLog in the following ways:

Using a configuration file, NLog.config, that is located in the same directory as your client application.
For more information, see https://github.com/NLog/NLog/wiki/Configuration-file.
Using the Configuration API to configure NLog in your application code.
For more information, see https://github.com/NLog/NLog/wiki/Configuration-API.