Apache ZooKeeper

Apache ZooKeeper: Open-Source Coordination Service

Apache ZooKeeper is an open-source coordination service for distributed applications. It helps coordinate large distributed systems by providing services like naming, configuration management, synchronization, and group services.

What is Apache ZooKeeper?

Apache ZooKeeper is an open-source coordination service for distributed applications. It provides services like:

• Naming: Provides naming registry for services, applications, hosts etc. This helps avoid collisions.
• Configuration management: Stores configuration information that can be used by applications.
• Synchronization: Provides distributed synchronization like locks.
• Group services: Provides services for groups of nodes like leader election.

ZooKeeper is designed to coordinate large distributed systems by maintaining configuration information, naming, providing distributed synchronization, and providing group services. It is a centralized service that enables distributed applications to coordinate with each other for achieving higher level goals.

Some key aspects of ZooKeeper:

• Highly reliable and available system. Built to work in case of failures.
• Simple API exposed to client applications.
• Built for coordination between large set of hosts.
• Hierarchical namespace to store data like file system.
• Support for change notifications and watches.

ZooKeeper bridges the gap between highly reliable storage systems required for coordination services and programming platforms that application developers prefer. It exposes a simple client API and implements coordination logic like synchronization primitives, group services etc as first class primitives. Due to its reliability and simplicity, it has become the coordination kernel for large distributed systems like Apache Hadoop, HBase, Kafka etc.

Apache ZooKeeper Features

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