In the chapter that we just finished, we learned about some functionalities of Elasticsearch that we won't probably use everyday or at least not everyone of us will use them. We discussed percolator – an upside down search functionality that allows us to index queries and find which documents match them. We learned about the spatial capabilities of Elasticsearch and we used suggesters to correct user spelling mistakes and build a highly efficient autocomplete functionality. We also used the Scroll API to efficiently fetch large number of results from our Elasticsearch indices.
In the next chapter, we will focus on clusters and its configuration. We will discuss node discovery, gateway, and recovery modules – what they are responsible for and how to configure them to match our needs. We will use templates and dynamic templates, and we will see how to install plugins extending Elasticsearch's out-of-the box functionalities. We will learn what are the caches of Elasticsearch caches...