ZooKeeper: Wait-Free Coordination for Internet-Scale Systems

This paper details the design and implementation of ZooKeeper, a high-performance coordination service for large-scale distributed systems. ZooKeeper provides a simple, wait-free API enabling developers to build various coordination primitives, such as locks and group membership, without server-side modifications. It achieves high throughput through relaxed consistency guarantees, allowing local read processing and efficient atomic broadcast for writes. The paper showcases ZooKeeper's performance and application in various real-world scenarios at Yahoo!, including a fetching service, a distributed indexer, and a message broker. Finally, it compares ZooKeeper to related systems, highlighting its unique strengths in performance and scalability. https://www.usenix.org/legacy/event/atc10/tech/full_papers/Hunt.pdf