In this chapter, we will cover the following recipes:
Creating a client in Scala
Managing indices
Managing mappings
Managing documents
Executing a standard search
Executing a search with aggregations
Introduction
Scala is becoming one of the most used languages in big data scenarios. This language provides a lot of facilities for managing data, such as immutability and functional programming.
In Scala, you can simply use the libraries seen in the previous chapter for Java, but they are not scalastic as they don't provide type safety (because many of these libraries take a JSON as a string) and it is easy to use asynchronous programming.
In this chapter, will see how to use elastic4s, a mature library, to use Elasticsearch in Scala. Its main features are:
Type safe concise DSL
Integrates with standard Scala futures
Uses the Scala collections library over Java collections
Returns option where the Java methods would return null
Uses Scala durations instead of strings/longs for time values
Uses typeclass for marshalling and unmarshalling classes to/from Elasticsearch documents, backed by Jackson, Circe, Json4s, and PlayJson implementations
Leverages the built-in Java client
Provides reactive-streams implementation
Provides embedded node and testkit sub-projects, ideal for your tests
In this chapter, we will see mainly examples about standard elastic4s DSL usage and some helpers such as the circe extension for the easy marshalling/unmarshalling of documents in classes.