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Log4Net

NuGet Package: NServiceBus.Log4Net (3.x)
Target Version: NServiceBus 7.x

Support for writing all NServiceBus log entries to Log4Net.

Usage

var layout = new PatternLayout
{
    ConversionPattern = "%d [%t] %-5p %c [%x] - %m%n"
};
layout.ActivateOptions();
var consoleAppender = new ConsoleAppender
{
    Threshold = Level.Debug,
    Layout = layout
};
consoleAppender.ActivateOptions();

var executingAssembly = Assembly.GetExecutingAssembly();
var repository = log4net.LogManager.GetRepository(executingAssembly);
BasicConfigurator.Configure(repository, consoleAppender);

LogManager.Use<Log4NetFactory>();

Filtering

NServiceBus can write a significant amount of information to the log. To limit this information use the filtering features of the underlying logging framework.

For example to limit log output to a specific namespace.

Here is a code configuration example for adding a Filter.

The Filter

public class NServiceBusLogFilter :
    FilterSkeleton
{
    public override FilterDecision Decide(LoggingEvent loggingEvent)
    {
        if (loggingEvent.LoggerName.StartsWith("NServiceBus."))
        {
            if (loggingEvent.Level < Level.Warn)
            {
                return FilterDecision.Deny;
            }
        }
        return FilterDecision.Neutral;
    }
}

Using the Filter

var appender = new ConsoleAppender
{
    Threshold = Level.Debug,
    Layout = new SimpleLayout(),
};

appender.AddFilter(new NServiceBusLogFilter());
appender.ActivateOptions();

var executingAssembly = Assembly.GetExecutingAssembly();
var repository = log4net.LogManager.GetRepository(executingAssembly);
BasicConfigurator.Configure(repository, appender);

NServiceBus.Logging.LogManager.Use<Log4NetFactory>();

Additional exception data

Starting from NServiceBus version 7.2, exceptions from failing message handlers might contain additional error information in the Exception.Data property. Log4Net does not log this information by default, but can be configured to do so using a custom PatternLayoutConverter:

class ExceptionDataConverter : PatternLayoutConverter
{
    protected override void Convert(TextWriter writer, LoggingEvent loggingEvent)
    {
        var exceptionData = loggingEvent.ExceptionObject?.Data;
        if (exceptionData != null)
        {
            foreach (var key in exceptionData.Keys)
            {
                writer.WriteLine("{0}: {1}", key, exceptionData[key]);
            }
        }
    }
}

The custom converter can then be registered and incorporated into the log layout:

var layout = new PatternLayout
{
    ConversionPattern = "%d %-5p %c - %m%n%exception_data"
};
layout.AddConverter("exception_data", typeof(ExceptionDataConverter));
layout.ActivateOptions();

Samples