anchor.diff:  [TIP]
   ====
   When using pre-2.6.1 Hadoop versions and JDK 1.8 in a Kerberos environment, HBase server can fail
  -and abort due to Kerberos keytab relogin error. Late version of JDK 1.7 (1.7.0_80) has the problem too.
  -Refer to link:https://issues.apache.org/jira/browse/HADOOP-10786[HADOOP-10786] for additional details.
  -Consider upgrading to Hadoop 2.6.1+ in this case.
  +and abort due to Kerberos keytab relogin error. Late version of JDK 1.7 (1.7.0_80) has the problem
  +too. Refer to link:https://issues.apache.org/jira/browse/HADOOP-10786[HADOOP-10786] for additional
  +details. Consider upgrading to Hadoop 2.6.1+ in this case.
   ====
   
   .Hadoop 2.6.x
  
positive.code: 
  ==== Starting 3.0.0 release
  
  The default implementation was switched to a master based connection registry. With this implementation, clients always contact the active or
  stand-by master RPC end points to fetch the the connection registry information. This means that the clients should have access to the list of active and master
  end points before they can do anything. This can be configured in the client configuration xml as follows:
  
  [source,xml]
  ----
  
negative.code: ==== `dfs.datanode.max.transfer.threads` (((dfs.datanode.max.transfer.threads)))
  
  An HDFS DataNode has an upper bound on the number of files that it will serve at any one time.
  Before doing any loading, make sure you have configured Hadoop's _conf/hdfs-site.xml_, setting the
  `dfs.datanode.max.transfer.threads` value to at least the following:
  
  [source,xml]
  ----
  