2.4. 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:

Table 10.2. Set Environment Variables
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.

	Important
	Double check that these environment variables are set correctly.