HDFS-6424. blockReport doesn't need to invalidate blocks on SBN. Contributed by Ming Ma.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1599397 13f79535-47bb-0310-9956-ffa450edef68
YARN-1913. With Fair Scheduler, cluster can logjam when all resources are consumed by AMs (Wei Yan via Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1599400 13f79535-47bb-0310-9956-ffa450edef68