What is Apache ZooKeeper?

Apache ZooKeeper is an open-source server which enables highly reliable distributed coordination.

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 itself is intended to be replicated. And each instance can manage multiple clients as shown below:

Releases of Apache ZooKeeper, zookeeper.jar:

JAR Name              JDK   FYI   Date
--------              ---   ---   ----------
zookeeper-3.8.0.jar     8   src   2022-02-25
zookeeper-3.7.0.jar     7   src   2021-03-17
zookeeper-3.4.5.jar               2012-11-05

For more information, see Apache ZooKeeper Website.

⇒ Download and Install Apache ZooKeeper Binary Package

⇐ Downloading and Reviewing zookeeper.jar

⇑ Downloading and Reviewing zookeeper.jar

⇑⇑ FAQ for Apache ZooKeeper