ZooKeeper Installation Apache ZooKeeper is a highly reliable and available service that provides coordination between distributed processes. Use the following sections to install, upgrade and administer ZooKeeper: Upgrading ZooKeeper from an Earlier CDH 5 Release Installing the ZooKeeper Packages Maintaining a ZooKeeper Server Viewing the ZooKeeper Documentation Viewing the Whirr Documentation Upgrading ZooKeeper from an Earlier CDH 5 Release