During upgrade from HDP 2.4.3 to HDP2.6.0 the express upgrade failes on the step "Yarn NodeMangers / Restarting NodeManger"

[#1]

SYMPTOM: During upgrade from HDP 2.4.3 to HDP2.6.0 the express upgrade failed on the step "Yarn NodeMangers / Restarting NodeManger."

ERROR:

2017-06-22
15:02:22,791 INFO recovery.ZKRMStateStore
(ZKRMStateStore.java:runWithRetries(1227)) - Exception while executing a ZK
operation. org.apache.zookeeper.KeeperException$AuthFailedException:
KeeperErrorCode = AuthFailed for /rmstore at
org.apache.zookeeper.KeeperException.create(KeeperException.java:123) at
org.apache.zookeeper.KeeperException.create(KeeperException.java:51) at
org.apache.zookeeper.ZooKeeper.create(ZooKeeper.java:783) 

ROOT CAUSE: The issue was with property Ambari-Yarn-Configs-"yarn-resourcemanager-zk-address" was set to localhost:2181

RESOLUTION:

Modified address to "{zk-server-hostname}:2181" resolved the issue. After which node managers were able to start successfully.