Merge -r 1476394:1476395 from trunk onto branch-2. Fixes HDFS-2576.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480135 13f79535-47bb-0310-9956-ffa450edef68
Merge -r 1477848:1477849 from trunk onto branch-2. Fixes HDFS-4778.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480136 13f79535-47bb-0310-9956-ffa450edef68
HDFS-2576. Fixed some compilation issues. Affects only branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480151 13f79535-47bb-0310-9956-ffa450edef68
YARN-651. Changed PBClientImpls of ContainerManager and RMAdmin to throw IOExceptions also. Contributed by Xuan Gong.
svn merge --ignore-ancestry -c 1480154 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480155 13f79535-47bb-0310-9956-ffa450edef68
YARN-582. Changed ResourceManager to recover Application token and client tokens for app attempt so that RM can be restarted while preserving current applications. Contributed by Jian He.
svn merge --ignore-ancestry -c 1480168 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480169 13f79535-47bb-0310-9956-ffa450edef68
YARN-646. Fix two typos in Fair Scheduler user guide. Contributed by Dapeng Sun.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480361 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5159. Change ValueAggregatorJob to add APIs which can support binary compatibility with hadoop-1 examples. Contributed by Zhijie Shen.
svn merge --ignore-ancestry -c 1480394 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480396 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5209. Fix units in a ShuffleScheduler log message.
Contributed by Tsuyoshi OZAWA


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480472 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5157. Bring back old sampler related code so that we can support binary compatibility with hadoop-1 sorter example. Contributed by Zhijie Shen.
svn merge --ignore-ancestry -c 1480474 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480476 13f79535-47bb-0310-9956-ffa450edef68
Fixing release date for 2.0.4-alpha.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480482 13f79535-47bb-0310-9956-ffa450edef68
YARN-631. Changed ClientRMProtocol api to throw IOException and YarnRemoteException. Contributed by Xuan Gong.
MAPREDUCE-5212. Handling YarnRemoteException separately from IOException in MR App after YARN-631. Contributed by Xuan Gong.
svn merge --ignore-ancestry -c 1480494 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480495 13f79535-47bb-0310-9956-ffa450edef68
YARN-630. Changed AMRMProtocol api to throw IOException and YarnRemoteException. Contributed by Xuan Gong.
MAPREDUCE-5226. Handling YarnRemoteException separately from IOException in MR App's use of AMRMProtocol after YARN-630. Contributed by Xuan Gong.
svn merge --ignore-ancestry -c 1480529 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480530 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-4942. mapreduce.Job has a bunch of methods that throw InterruptedException so its incompatible with MR1. (rkanter via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480754 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9550. Remove aspectj dependency. (kkambatl via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480784 13f79535-47bb-0310-9956-ffa450edef68
YARN-507. Add interface visibility and stability annotations to FS interfaces/classes. (kkambatl via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480800 13f79535-47bb-0310-9956-ffa450edef68
YARN-637. FS: maxAssign is not honored. (kkambatl via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480803 13f79535-47bb-0310-9956-ffa450edef68
YARN-655. Fair scheduler metrics should subtract allocated memory from available memory. (sandyr via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480810 13f79535-47bb-0310-9956-ffa450edef68
YARN-598. Add virtual cores to queue metrics. (sandyr via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480817 13f79535-47bb-0310-9956-ffa450edef68
YARN-568. Add support for work preserving preemption to the FairScheduler.
Contributed by Carlo Curino and Sandy Ryza


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1480837 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4810. several HDFS HA tests have timeouts that are too short. Contributed by Chris Nauroth


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