Aggregations

Apart from the improvements and new features that Elasticsearch 1.0 brings, it also includes a highly anticipated framework, which moves Elasticsearch to a new position—a full-featured analysis engine. Now, you can use Elasticsearch as a key part of various systems that process massive volumes of data, allow you to extract conclusions, and visualize that data in a human-readable way. Let's see how this functionality works and what we can achieve by using it.

General query structure

To use aggregation, we need to add an additional section in our query. In general, our queries with aggregations will look like the following code snippet:

{
  "query": { … },
  "aggs" : { … }
}

In the aggs property (you can use aggregations if you want; aggs is just an abbreviation), you can define any number of aggregations. One thing to remember though is that the key defines the name of the aggregation (you will need it to distinguish particular aggregations in the server response). Let's take our...