Merged revision(s) 1617799 from hadoop/common/trunk:
HDFS-6247. Avoid timeouts for replaceBlock() call by sending intermediate responses to Balancer (vinayakumarb)
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git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1619084 13f79535-47bb-0310-9956-ffa450edef68