ZooKeeper
lastmod 2023-04-12created 2016-12-234 edits
Apache ZooKeeper is an effort to develop and maintain an open-source server which enables highly reliable distributed coordination.
An open-source project that provides a distributed coordination service
What is ZooKeeper?
ZooKeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services. All of these kinds of services are used in some form or another by distributed applications. Each time they are implemented there is a lot of work that goes into fixing the bugs and race conditions that are inevitable. Because of the difficulty of implementing these kinds of services, applications initially usually skimp on them ,which make them brittle in the presence of change and difficult to manage. Even when done correctly, different implementations of these services lead to management complexity when the applications are deployed.
ZooKeeper does not coordinate application tasks directly; it is a tool that makes it easy to develop such coordination. Its API makes it easy to implement tasks such as synchronization and master election. It centralizes the information of each application and provides services such as configuration management, group management, naming, and synchronization. ZooKeeper's data is stored in memory, and snapshots are saved to persistent storage.
What is a distributed coordination service?
A service that handles information sharing between systems, status checks, and locks for synchronization between servers in a distributed system