ZooKeeper
ZooKeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services in distributed systems. It acts as a coordination service that helps manage and coordinate large clusters of servers, ensuring consistency and reliability across distributed applications. It uses a hierarchical namespace similar to a file system and provides primitives like locks, queues, and leader election to simplify distributed programming.
Developers should learn and use ZooKeeper when building or managing distributed systems that require high availability, fault tolerance, and coordination among multiple nodes, such as in microservices architectures, big data platforms like Apache Kafka or Hadoop, or cloud-based applications. It is essential for scenarios involving service discovery, configuration management, leader election, and distributed locking, as it provides a robust and scalable way to handle these challenges without reinventing the wheel.