Question

Playing with log4net, I have seen the possibility to use a per-thread stack of context labels called the NDC.

The labels pushed on this stack are displayed in a PatternLayout by specifying the %x or the %ndc format parameter.

The usage is something like:

ILog log = log4net.LogManager.GetLogger(...) ;  //pattern layout format: '[%ndc] - %message%newline'  log.Info('message 1');  using(log4net.NDC.Push('context') {     using(log4net.NDC.Push('inner_context')     {       log.Info('message 2');      }     log.Info('message 3');  } log.Info('message 4');  

The output is something like:

null - message 1 context inner_context - message 2 context - message 3 null - message 4 

In your programming experience with log4net, when did you find this feature to be useful?

Answer 1

In a server application such as ASP.NET.

For example, you can push information about the current request on to the NDC.