Zeppelin Notebooks fail with NPE or hbase.MasterNotRunningException after SmartSense Upgrade

[#1]

Symptoms:

After recently upgrading SmartSense, you successfully log into Activity-Explorer and attempt to execute any pre-installed notebooks only to encounter one of the following errors:

RpcRetryingCaller {globalStartTime=1473694857754, pause=100, retries=35}, 
org.apache.hadoop.hbase.MasterNotRunningException: 
com.google.protobuf.ServiceException: 
org.apache.hadoop.hbase.exceptions.ConnectionClosingException: 
Call to node1.abcxyz.com/192.168.1.1:61300 failed on local exception: 
org.apache.hadoop.hbase.exceptions.ConnectionClosingException: Connection to node1.abcxyz.com/192.168.1.1:61300 is closing. Call id=4, waitTime=2

or

192.168.1.1:61300 is closing. Call id=32, waitTime=4 
RpcRetryingCaller{globalStartTime=1473456721387, pause=100, retries=35}, 
org.apache.hadoop.hbase.MasterNotRunningException: 
com.google.protobuf.ServiceException: 
java.io.IOException: Broken pipe 

RpcRetryingCaller{globalStartTime=1473456721387, pause=100, retries=35}, 
org.apache.hadoop.hbase.MasterNotRunningException: 
com.google.protobuf.ServiceException: 
org.apache.hadoop.hbase.exceptions.ConnectionClosingException: Call to node1.abcxyz.org/192.168.1.1:61300 failed on local exception: 
org.apache.hadoop.hbase.exceptions.ConnectionClosingException: Connection to node1.abcxyz.org/192.168.1.1:61300 is closing

Diagnosis:

This can occur when certain dependent libraries were not correctly loaded after the upgrade of SmartSense.

Solution:

Try the following steps to remedy the solution:

1. Restart AMS (specifically looking for the collector to restart) then restart Activity-Analyzer and last restart Activity-Explorer. These restarts should correct the loading issue of the dependent libraries.
2. If the problem still persists, add the following export statement to the zeppelin-env.sh (typically found at /usr/hdp/share/hst/activity-explorer/conf) on the node where Activity-Explorer is installed - once added restart Activity-Explorer:

export CLASSPATH=${ZEPPELIN_CLASSPATH}