RemotingAppender ClassApache log4net™ SDK Documentation
Delivers logging events to a remote logging sink.
Inheritance Hierarchy

OnlineSystem Object
  log4net.Appender AppenderSkeleton
    log4net.Appender BufferingAppenderSkeleton
      log4net.Appender RemotingAppender

Namespace: log4net.Appender
Assembly: log4net (in log4net.dll) Version: 1.2.15.0 (1.2.15.0)
Syntax

public class RemotingAppender : BufferingAppenderSkeleton
Remarks

This Appender is designed to deliver events to a remote sink. That is any object that implements the RemotingAppender IRemoteLoggingSink interface. It delivers the events using .NET remoting. The object to deliver events to is specified by setting the appenders Sink property.

The RemotingAppender buffers events before sending them. This allows it to make more efficient use of the remoting infrastructure.

Once the buffer is full the events are still not sent immediately. They are scheduled to be sent using a pool thread. The effect is that the send occurs asynchronously. This is very important for a number of non obvious reasons. The remoting infrastructure will flow thread local variables (stored in the OnlineCallContext), if they are marked as OnlineILogicalThreadAffinative, across the remoting boundary. If the server is not contactable then the remoting infrastructure will clear the OnlineILogicalThreadAffinative objects from the OnlineCallContext. To prevent a logging failure from having side effects on the calling application the remoting call must be made from a separate thread to the one used by the application. A OnlineThreadPool thread is used for this. If no OnlineThreadPool thread is available then the events will block in the thread pool manager until a thread is available.

Because the events are sent asynchronously using pool threads it is possible to close this appender before all the queued events have been sent. When closing the appender attempts to wait until all the queued events have been sent, but this will timeout after 30 seconds regardless.

If this appender is being closed because the OnlineProcessExit event has fired it may not be possible to send all the queued events. During process exit the runtime limits the time that a OnlineProcessExit event handler is allowed to run for. If the runtime terminates the threads before the queued events have been sent then they will be lost. To ensure that all events are sent the appender must be closed before the application exits. See Shutdown  for details on how to shutdown log4net programmatically.

See Also