https://community.cloudera.com/t5/Support-Questions/Hbase-region-servers-not-able-to-connect-to-master-after/m-p/198702#M160750 <P>Have you performed a sanity check that the RegionServer which gave this error can connect to that IP+port? You can easily use telnet to perform this check (e.g. `telnet 172.16.3.196 16000`). If you get a connection refused error, either the HBase master is not running or there is a network issue preventing this node from talking to the Master.</P> Thu, 13 Apr 2017 22:58:19 GMT elserj 2017-04-13T22:58:19Z