When using Kerberos, it is import to use fully-qualified domain names and not use localhost. Please ensure that the fully qualified hostname of each server is used in the following locations:

Failure to do so, may result in errors similar to the following:

2016-01-08 16:08:57,888 ERROR [pool-26-thread-1-SendThread(localhost:2181)] o.a.zookeeper.client.ZooKeeperSaslClient An error: (java.security.PrivilegedActionException: javax.security.sasl.SaslException: GSS initiate failed [Caused by GSSException: No valid credentials provided (Mechanism level: Server not found in Kerberos database (7) - LOOKING_UP_SERVER)]) occurred when evaluating ZooKeeper Quorum Member's received SASL token. ZooKeeper Client will go to AUTH_FAILED state.

If there are problems communicating or authenticating with Kerberos, this Troubleshooting Guide may be of value.

One of the most important notes in the above Troubleshooting guide is the mechanism for turning on Debug output for Kerberos. This is done by setting the sun.security.krb5.debug environment variable. In NiFi, this is accomplished by adding the following line to the _$NIFI_HOME/conf/bootstrap.conf` file:

java.arg.16=-Dsun.security.krb5.debug=true

This will cause the debug output to be written to the NiFi Bootstrap log file. By default, this is located at $NIFI_HOME/logs/nifi-bootstrap.log. This output can be rather verbose but provides extremely valuable information for troubleshooting Kerberos failures.