In this chapter, we discussed Elasticsearch administration. We started by learning how to perform backups of our indices and how to monitor our cluster health and state using its API. We controlled cluster shard rebalancing and learned how to adjust shard allocation according to our needs. We've used the CAT API to get information about Elasticsearch in human-readable form and we've warmed up our queries to make them faster. Finally, we've used aliases to allow a better management of our indices and to have more flexibility.

In the next and final chapter of the book, we will focus on a hypothetical online library store to see how to make Elasticsearch work in practice. We will start with a brief introduction and hardware considerations. We will tune a single instance of Elasticsearch and properly configure our cluster by discussing each of its parts and providing a proper architecture. We will vertically expand the cluster and prepare it for both high querying and high indexing load. Finally, we will learn how to monitor such a prepared cluster.