Apache ZooKeeper

Apache ZooKeeper is an open-source server for highly reliable distributed coordination, providing configuration management, naming, synchronization and leader election for the clustered applications that rely on it. Yahoo! Research originated the project around 2007 to address the coordination problems repeatedly reinvented by Yahoo's various distributed systems, and it later became a project of the Apache Software Foundation. ZooKeeper exposes a small set of primitives, backed by its own ZAB atomic broadcast protocol, that let a cluster of servers agree on shared state even as individual machines fail, and it became a dependency of many other distributed systems, including Apache Hadoop and Apache Kafka. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/