Configure and Start Apache ZooKeeper

Before you can upgrade Apache ZooKeeper, you must have first upgraded your HDP components to the latest version (in this case, 2.3.6). This section assumes that you have already upgraded your components for HDP 2.3.6. If you have not already completed these steps, return to Getting Ready to Upgrade and Upgrade 2.0 Components for instructions on how to upgrade your HDP components to 2.3.6.

	Tip
	If you are running a highly available cluster, upgrade ZooKeeper before you upgrade HDFS. This best practice lets the upgraded ZKFC work with your primary NameNode and your Standby NameNode.

	Note
	The `su` commands in this section use keywords to represent the Service user. For example, "zookeeper" is used to represent the ZooKeeper Service user. If you are using another name for your Service users, you will need to substitute your Service user name in each of the `su` commands.

Replace your configuration after upgrading. Replace the ZooKeeper template configuration in /etc/zookeeper/conf.
Start ZooKeeper.
On all the ZooKeeper server host machines, run the following command to start ZooKeeper and the ZKFC:
su - zookeeper -c "export ZOOCFGDIR=/usr/hdp/current/zookeeper-server/conf ; export ZOOCFG=zoo.cfg; source /usr/hdp/current/zookeeper-server/conf/zookeeper-env.sh ; /usr/hdp/current/zookeeper-server/bin/zkServer.sh start"
/usr/hdp/current/hadoop-client/sbin/hadoop-daemon.sh start zkfc

​Configure and Start Apache ZooKeeper

Configure and Start Apache ZooKeeper