Blocker Description
Similarly to HDFS-5403, getFileBlockLocations() fail between old (1.x, 0.23.x) and new (2.x), but this is worse since both directions won't work. This is caused by the removal of "name" field from the serialized json format of DatanodeInfo.
2.x namenode should include "name" (ip:port) in the response and 2.x webhdfs client should use "name", if "ipAddr" and "xferPort" don't exist in the response.
