merge YARN-720 and MAPREDUCE-5291 from trunk. container-log4j.properties should not refer to mapreduce properties. Update MRApp to use YARN properties for log setup. Contributed by Zhijie Shen.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488830 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1347867 from trunk for HADOOP-8469. Make NetworkTopology class pluggable.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488838 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1351445 from trunk for HADOOP-8470. Add NetworkTopologyWithNodeGroup, a 4-layer implementation of NetworkTopology.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488839 13f79535-47bb-0310-9956-ffa450edef68
Merge -c 1488840 from trunk to branch-2 to fix YARN-730. Fix NMClientAsync to remove completed containers. Contributed by Zhijie Shen.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488841 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1353807 from trunk for HDFS-3498. Support replica removal in BlockPlacementPolicy and make BlockPlacementPolicyDefault extensible for reusing code in subclasses.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488844 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1357442 from trunk for HDFS-3601. Add BlockPlacementPolicyWithNodeGroup to support block placement with 4-layer network topology.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488845 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-2' into branch-2-gd
Merge remote branch 'origin/branch-2-gd' into fb-HADOOP-7435-branch-2-gd