In the last six chapters, we learned all the essentials about Apache ZooKeeper, which has given us a firm grip on its background concepts, usage, and administration. We read about community projects such as Curator, which makes programming with ZooKeeper much simpler, and also adds more functionality on top of it. We saw how Exhibitor makes the managing of ZooKeeper instances easier in a production environment. ZooKeeper is one of the successful projects from Apache Software Foundation, and has gained wide adoption by other projects and organizations in their production platforms.

In this chapter, we are going to read about how ZooKeeper is used by software projects for their inherent need of distributed coordination. We will particularly look at the following projects that use and depend on ZooKeeper for some of their functionality:

We will also look at how ZooKeeper is used by organizations...