The reactive-stack web framework, Spring WebFlux, has been added to Spring 5.0. It is fully non-blocking, supports reactive streams back-pressure, and runs on such servers as Netty, Undertow, and Servlet 3.1+ containers.
Reactive processing is a paradigm that enables developers to build non-blocking, asynchronous applications that can handle back-pressure (flow control). Reactive systems better utilize modern processors. Also, the inclusion of back-pressure in reactive programming ensures better resilience between decoupled components.