In this chapter, we have learned how to write client programs for Apache ZooKeeper using three different languages: Java, C, and Python. We saw how to develop simple client code for connecting to a ZooKeeper server, implementation of watchers, and even more advanced use cases of development. It is recommended that you go through the API documentation of the individual client libraries so as to be well versed with the methods and constructs of each one of them.

In the next chapter, we will look into some advanced topics of ZooKeeper programming, where we will look at the algorithms and steps to implement common distributed system tasks such as leader election, group membership, and so on, using ZooKeeper primitives. We will also learn how to implement distributed data structures such as locks, barriers, and queues with ZooKeeper.