Apache ZooKeeper is an open-source coordination service for distributed systems. It enables reliable configuration management, synchronization, and naming across clusters. ZooKeeper is widely used to manage distributed applications by providing a consistent and fault-tolerant way to coordinate nodes and maintain system state.

Features of Apache ZooKeeper:

• Centralized service for maintaining configuration and naming.
• Supports distributed synchronization and group coordination.
• High availability through leader election and replication.
• Efficient and scalable architecture for large distributed systems.

To check the ZooKeeper version, run $ ls /opt | grep zookeeper

Disclaimer: Apache ZooKeeper is an open-source project released under the Apache License 2.0. It is developed and maintained by the Apache Software Foundation and the open-source community. ZooKeeper is provided "as is," without any warranty.