Logging communication using LogWriter 

Communication logs are very useful when troubleshooting issues. Whenever you run into a problem, a log makes it possible to see what is going on.

To start logging, just add the following line into your code (after creating the SyslogClient or SyslogServer object):

// start logging to a file
server.LogWriter = new Rebex.FileLogWriter(@"C:\MyData\log.txt");

' start logging to a file
server.LogWriter = New Rebex.FileLogWriter("C:\MyData\log.txt")

Sample server-side log file:

2021-03-16 18:01:12.111 INFO SyslogServer(1)[30] Info: Starting server.
2021-03-16 18:01:12.113 DEBUG SyslogServer(1)[30] Info: Binding 'Udp' protocol listener to the 0.0.0.0:514 endpoint.
2021-03-16 18:01:12.127 DEBUG SyslogServer(1)[30] Info: Binding 'Tcp' protocol listener to the 0.0.0.0:514 endpoint.
2021-03-16 18:01:12.129 DEBUG SyslogServer(1)[30] Info: Binding 'Tls' protocol listener to the 0.0.0.0:6514 endpoint.
2021-03-16 18:01:12.130 INFO SyslogServer(1)[30] Info: Server started.
2021-03-16 18:01:12.183 DEBUG SyslogServer(1)[27] Connection #1: Accepted new connection: 0.0.0.0:514<==Tcp==>127.0.0.1:50794.
2021-03-16 18:01:12.188 DEBUG SyslogServer(1)[27] Connection #1: Connection added to internal list.
2021-03-16 18:01:12.191 DEBUG SyslogServer(1)[26] Connection #1: Received 29 bytes.
2021-03-16 18:01:12.193 DEBUG SyslogServer(1)[26] Connection #1: Message parsed.
2021-03-16 18:01:12.194 DEBUG SyslogServer(1)[27] Connection #1: Closing connection 0.0.0.0:514<==Tcp==>127.0.0.1:50794.

Sample client-side log file:

2021-03-16 18:38:40.295 INFO SyslogClient(1)[9] Info: Connecting to localhost:514 using TCP/IP.
2021-03-16 18:38:40.295 INFO SyslogClient(1)[9] Info: Sending Syslog message (29 bytes).
2021-03-16 18:38:40.295 DEBUG SyslogClient(1)[9] Info: Disposing client instance.

Log verbosity levels 

There are several levels of log verbosity:

• Error - logs error messages only
• Info - default level; logs important informative messages as well
• Debug - logs all messages useful for debugging purposes
• Verbose - very detailed log for advanced analysis; logs content of communication packets
  Warning: At the Verbose level, user credentials are written to the log as well.

To specify a log level, just pass an argument to FileLogWriter's constructor:

// start logging to a file at debug level
server.LogWriter = new Rebex.FileLogWriter(@"C:\MyData\log.txt", Rebex.LogLevel.Debug);

' start logging to a file at debug level
server.LogWriter = New Rebex.FileLogWriter("C:\MyData\log.txt", Rebex.LogLevel.Debug)

Built-in log writers 

Text file

To log into a text file, use FileLogWriter:

// start logging to a file at debug level
server.LogWriter = new Rebex.FileLogWriter(@"C:\MyData\log.txt", Rebex.LogLevel.Debug);

' start logging to a file at debug level
server.LogWriter = New Rebex.FileLogWriter("C:\MyData\log.txt", Rebex.LogLevel.Debug)

.NET trace listener

To log to .NET Trace Listeners, use TraceLogWriter:

// start logging to subscribed trace listeners
server.LogWriter = new Rebex.TraceLogWriter(Rebex.LogLevel.Debug);

' start logging to subscribed trace listeners
server.LogWriter = New Rebex.TraceLogWriter(Rebex.LogLevel.Debug)

Standard output stream

To log to the standard output stream, use ConsoleLogWriter:

// start logging to the standard output stream at debug level
server.LogWriter = new Rebex.ConsoleLogWriter(Rebex.LogLevel.Debug);

' start logging to the standard output stream at debug level
server.LogWriter = New Rebex.ConsoleLogWriter(Rebex.LogLevel.Debug)

Logging to multiple log writers

To log to more log writers at the same time, use TeeLogWriter:

var consoleLogWriter = new Rebex.ConsoleLogWriter(Rebex.LogLevel.Debug);
var fileLogWriter = new Rebex.FileLogWriter(@"C:\MyData\log.txt", Rebex.LogLevel.Info);

// start logging to both console and file log writers
server.LogWriter = new Rebex.TeeLogWriter(consoleLogWriter, fileLogWriter);

Dim consoleLogWriter = New Rebex.ConsoleLogWriter(Rebex.LogLevel.Debug)
Dim fileLogWriter = New Rebex.FileLogWriter("C:\MyData\log.txt", Rebex.LogLevel.Info)

' start logging to both console and file log writers
server.LogWriter = New Rebex.TeeLogWriter(consoleLogWriter, fileLogWriter)

Writing custom log writers 

// Sample log writer that logs to the standard error output stream
public class MyLogWriter : LogWriterBase
{
    protected override void WriteMessage(string message)
    {
        Console.Error.WriteLine("Rebex: {0}", message);
    }
}

' Sample log writer that logs to the standard error output stream
Public Class MyLogWriter
    Inherits LogWriterBase

    Protected Overrides Sub WriteMessage(ByVal message As String)
        Console.Error.WriteLine("Rebex: {0}", message)
    End Sub
End Class