Prepare the Ambari Server Host for Rollback

Log into the Ambari server host and set the following environment variables to prepare for the rollback procedure:

Variable	Value
export AMBARI_USER=AMBARI_USERNAME	Substitute the value of the administrative user for Ambari Web. The default value is admin.
export AMBARI_PW=AMBARI_PASSWORD	Substitute the value of the administrative password for Ambari Web. The default value is admin.
export AMBARI_PORT=AMBARI_PORT	Substitute the Ambari Web port. The default value is 8080.
export AMBARI_PROTO=AMBARI_PROTOCOL	Substitute the value of the protocol for connecting to Ambari Web. Options are http or https. The default value is http.
export CLUSTER_NAME=CLUSTER_NAME	Substitute the name of your cluster, set during the Ambari Install Wizard process. For example: mycluster.
export NAMENODE_HOSTNAME=NN_HOSTNAME	Substitute the FQDN of the host for the non-HA NameNode. For example: nn01.mycompany.com.
export ADDITIONAL_NAMENODE_HOSTNAME=ANN_HOSTNAME	Substitute the FQDN of the host for the additional NameNode in your HA setup.
export SECONDARY_NAMENODE_HOSTNAME=SNN_HOSTNAME	Substitute the FQDN of the host for the secondary NameNode for the non-HA setup.
export JOURNALNODE1_HOSTNAME=JOUR1_HOSTNAME	Substitute the FQDN of the host for the first Journal Node.
export JOURNALNODE2_HOSTNAME=JOUR2_HOSTNAME	Substitute the FQDN of the host for the second Journal Node.
export JOURNALNODE3_HOSTNAME=JOUR3_HOSTNAME	Substitute the FQDN of the host for the third Journal Node.

Double check that these environment variables are set correctly.