In this chapter, we learned how to use ZooKeeper for performance optimization purposes, and we covered how to set up, configure, and deploy ZooKeeper. We also learned about the different applications of ZooKeeper that can help us optimize Solr's performance.

In the next chapter, we will list down some useful and necessary references to the official and documentation pages that will help you to explore the topics and concepts even further. It also covers the recommended books and video tutorials that will facilitate you to enhance your learning curve.