Data analytics using aggregations

Elasticsearch is a search engine at its core but what makes it more usable is its ability to perform complex data analytics in an easy and simple way. The volume of data is growing rapidly and companies want to perform analysis on data in real-time. Whether it is log, real-time streaming of data, or static data, Elasticsearch works wonderfully in creating a summarization of data through its aggregation capabilities.

In the previous editions of Mastering Elasticsearch we have covered a lot of ground on aggregations but we will revisit the important aggregations in this chapter again, and then cover the new aggregation type which is introduced in Elasticsearch version 5.x.

Instant aggregations in Elasticsearch 5.0

Aggregations were too costly at the beginning of Elasticsearch and used to be the biggest consumer of memory. In Elasticsearch 1.4, there was a new feature which was known as shard query cache, which was further renamed shard request cache. The benefit...