Configure and Start Apache ZooKeeper
![[Tip]](../common/images/admon/tip.png) | Tip |
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If you are running a highly available HDFS cluster, configure and restart Apache ZooKeeper before you upgrade HDFS. This best practice lets the upgraded ZKFC work with your primary NameNode and your Standby NameNode. |
Before you can upgrade the ZooKeeper service, you must have first upgraded your HDP components to the latest version (in this case, 2.4.2). This section assumes that you have already upgraded your components for HDP 2.4.2. If you have not already completed these steps, return to Getting Ready to Upgrade and Upgrade 2.3 Components for instructions on how to upgrade your HDP components to 2.4.2.
Replace your configuration after upgrading on all the ZooKeeper nodes. Replace the ZooKeeper template configuration in
/etc/zookeeper/conf.Start ZooKeeper.
On all ZooKeeper server host machines, run the following command to start ZooKeeper and the ZKFC:
su - zookeeper -c "/usr/hdp/current/zookeeper-server/bin/zookeeper-server start"