Hands-On Reactive Programming in Spring 5

Advanced - async and parallel in Reactive Streams

In the previous sections, we discussed the conceptual behaviors of Reactive Streams. However, there was no mention of asynchronous and non-blocking behaviors of reactive pipes. So, let's dig into the Reactive Streams standard and analyze those behaviors.

On one hand, the Reactive Streams API states, in rules 2.2 and 3.4, that the processing of all signals produced by the Publisher and consumed by the Subscriber should be non-blocking and non-obstructing. Consequently, we may be sure that we may efficiently utilize one node or one core of the processor, depending on the execution's environment. 

On the other hand, the efficient utilization of all processors or cores requires parallelization. ...