In this chapter, we focused on scaling and tuning Elasticsearch. We started with the hardware preparations and decisions we need to make. Next, we tuned a single Elasticsearch node as much as we could and after that we configured the whole cluster to work as well as it could. We discussed vertical expansion possibilities and we learned how to monitor our cluster once it hits the production environment.

So now we have reached the end of the book. We hope that it was a nice reading experience and that you found the book interesting. Since the previous edition of the book, Elasticsearch has changed a lot. Not only when it comes to versions, but also when it comes to functionalities. Some of the features are no longer there, some of them were moved to plugins, and of course new features were added. We really hope that you have learned something from this book and now you will find it easier to use Elasticsearch every day – no matter if you are a beginner in this world or a semi–experienced Elasticsearch user. As the authors of this book, but also as Elasticsearch users ourselves, we tried to bring you, our readers, the best reading experience we could. Of course Elasticsearch is more than we described in the book, especially when it comes to monitoring and administration capabilities and API. However, the number of pages is limited and if we were to describe everything in great details we would have ended up with a book one thousand pages long. We need to remember that Elasticsearch is not only user friendly but also provides a large amount of configuration options, querying possibilities, and so on. Due to that, we had to choose which functionalities to describe in greater details, which had to be only mentioned, and which had to be totally skipped. As with the two previous editions of the book you are holding, we hope that we made the right choice and that you are happy about what you've read.

We would also like to say that it is worth remembering that Elasticsearch is constantly evolving. When writing this book, we went through a few stable versions finally making it to the release of Elasticsearch 2.2. Even back then we knew that new features and improvements were coming, like some of the changes mentioned in the book that will be part of the next release, or at least they are planned to be. Be sure to check the official documentation of Elasticsearch periodically for the release notes for new versions of Elasticsearch, if you want to be up to date with the new features being added. We will also be writing about new features that we think are worth mentioning on www.elasticsearchserverbook.com. So if you are interested, visit the site from time to time.

Once again thank you for the time you've spent with the book.