2.7. Summary

Let’s review what you’ve learned in this chapter:

Elasticsearch is document-oriented, scalable, and schema-free by default.

Although you can form a cluster with the default settings, you should adjust at least some of them before you move on; for example, cluster name and heap size.

Indexing requests are distributed among the primary shards and replicated to those primary shards’ replicas.

Searches are done using a round-robin approach between complete sets of data, whether those are made up of shards or replicas. The node that received the search request then aggregates partial results from individual shards and returns those results to the application.

Client applications may be unaware of the sharded nature of each index or what the cluster looks like. They care only about indices, types, and document IDs. They use the REST API to index and search for documents.

You can send new documents and search parameters as the JSON payload of an HTTP request and you’ll get back a JSON reply with the results.

In the next chapter you’ll get the foundation you need to organize your data effectively in Elasticsearch, learn what types of fields your documents can have, and become familiar with all the relevant options for indexing, updating, and deleting.