I assume that MDC stands here for Mapped Diagnostic Context?

Currently, we use JUL logger and from what I read it doesn't support MDC so adding support for it would require complete overhaul of logging in Tigase. What's more, considering that Tigase is multi-component and multi-threaded, passing correctly id between would be problematic.

Though, we do include packet in most of the log entries so tracking packet processing (using it's ID) should be fine (even though not ideal).

Yeah :). Perfect thank you, will try the tracking on each packet logs.