The shortest description of Zookeeper:
ZK has a very simple, file system like API. One can create a path, set the value of a path, read the value of a path, delete a path, and list the children of a path. ZK does a couple of more interesting things: (a) one can register a watcher on a path and get notified when the children of a path or the value of a path is changed, (b) a path can be created as ephemeral, which means that if the client that created the path is gone, the path is automatically removed by the ZK server. However, don’t let the simple API fool you.
The rest of the article is about handling client side state.
Original title and link for this post: Zookeeper experience (published on the NoSQL blog: myNoSQL)