Affects Version/s: 0.4.0
Fix Version/s: 0.5.0
HADOOP-392 introduced a new TreeMap member (datanodeMapByName) in the name node.
It is used solely for reporting the data nodes in the UI sorted by their names.
I think it is quite inefficient both time and space-wise to support an excessive
data structure just for that.
Suppose the UI will also require sorting by last heartbeat and/or by the available space....
I think DFSNodesStatus() should just sort the original datanodeMap before returning the list.