ZooKeeper

Learn why it is recommended to install ZooKeeper on a node where it can have unobstructed access to the disk.

ZooKeeper is sensitive to disk latency. While it only uses a modest amount of resources, having ZooKeeper swap out or wait for a disk operation can result in that ZooKeeper node being considered ‘dead’ by its quorum peers. For this reason, Cloudera recommends against deploying ZooKeeper on worker nodes where loads are unpredictable and are prone to spikes. It is acceptable to deploy Zookeeper on master nodes where load is more uniform and predictable (or on any node where it can have unobstructed access to disk).