YARN-1210. Changed RM to start new app-attempts on RM restart only after ensuring that previous AM exited or after expiry time. Contributed by Omkar Vinit Joshi.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1543310 13f79535-47bb-0310-9956-ffa450edef68
YARN-674. Fixed ResourceManager to renew DelegationTokens on submission asynchronously to work around potential slowness in state-store. Contributed by Omkar Vinit Joshi.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1543312 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5428. Under construction files deletion after snapshot+checkpoint+nn restart leads nn safemode. Contributed by Jing Zhao.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1543329 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10107. Server.getNumOpenConnections may throw NPE. Contributed by Kihwal Lee.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1543335 13f79535-47bb-0310-9956-ffa450edef68