This causes any messages of info or higher by anything prefixed SubSystem to be logged twice. I understand why this would happen, but this is clearly not my intent here -- I just want to see Trace messages for one subsystem, and Info or up for anything else.
I can't find anyone that's discussed this before, and nothing in the documentation that states how it works either way. Can someone point me in the right direction if this conversation/documentation exists?
Otherwise, I'd propose a change to either:
* Modify nlog so it doesn't do these duplicates -- basically, once a given message has been written to a given target, don't ever write to the same target again.
* Add a DuplicateFilter, which would cache the previous message(s) (not sure if 1 is enough or if it would need multiples, in the case of a multi-threaded app), and then basically if the previous entry is identical (same message/timestamp/etc) to the current one, don't log it.
I kind of thing the first option is the way to go. I can't imagine why this behaviour would ever be desirable -- and even if it is, all you'd have to do is create a copy of your target with a different name, and you could log it twice.