The Spring Data Reactive Couchbase module may be enabled with the spring-boot-starter-data-couchbase-reactive starter module. It enables the reactive access for Couchbase (https://www.couchbase.com). The ReactiveCouchbaseRepository interface extends basic ReactiveCrudRepository, additionally requiring the type of entity ID to extend the Serializable interface.

The default implementation of the ReactiveCouchbaseRepository interface is built on top of the RxJavaCouchbaseOperations interface. The RxJavaCouchbaseTemplate class implements RxJavaCouchbaseOperations. At this point, it should be evident that the reactive Couchbase connector uses the RxJava library for RxJavaCouchbaseOperations. As the ReactiveCouchbaseRepository methods return the Mono and Flux types and the RxJavaCouchbaseOperations methods return the Observable type, reactive type conversion is required. It happens at the level of the repository implementation.

The reactive Couchbase connector is built on top of the reactive Couchbase driver. The latest Couchbase driver 2.6.2 uses RxJava version 1.3.8, the last release of the 1.x branch. Consequently, backpressure support may be limited with the Couchbase connector. However, it has an entirely non-blocking stack through the Netty framework and the RxJava library, so it should not waste any application resources.