Hello, I am interested in converting my application to logback, but I have some performance concerns about its MDC implementation. My application uses MDC extensively for async IO, so it may call MDC.put and MDC.remove extremely frequently, because each thread may be handling 1000s of interleaved connections using state machines. I see in the source for LogbackMDCAdapter that for every call to MDC.put and MDC.remove, the HashMap is cloned. Could this clone potentially be handled during the creation of LoggingEvents instead of the call to MDC? The creation of logging events is expected to entail memory allocation, so it seems that it would be a better fit there, even if some applications might have a very low number of calls to MDC versus logging calls. It seems that the same energy expended in minimizing log statement impact when logging is turned off should also apply to MDC calls. Thanks Matt