Reactive Programming

Internal

• Software Architecture
• Java 9 Reactive Streams
• Stream Processing

Overview

The underlying principles of reactive applications inform overall system design.

Message-driven runtime.

Programming model.

Resource utilization. Responsiveness is achieved by efficiently using the hardware. Better resource utilization is a component of scalability.

Decoupling promotes scale-out, as various components can be scaled independently. Asynchronous communication is key to achieve decoupling. It separates the lifecycle of the request initiator from the lifecycle of the request target.

Reactive streams.

Same reactive principles apply to the local (application) level of the system and to the distributed system, allowing composing a distributed system from reactive building blocks from bottom up.

In the academic world, "reactive" stands for "functional reactive programming" (FPR), or "functional reactive activation".

Reactive System Tenets according to the Reactive Manifesto

• Responsiveness refers to the capability of the system to be consistently responsive to the user and never fail; it refers to the value brought by such systems.
• Resilience is the capability of the system to self-heal, and refers to form in which reactive systems are delivered.
• Elasticity is the capability of the system to scale out and up/ in and down across physical and cloud infrastructure refers to form in which reactive systems are delivered.
• Message-driven refers to the means used to implement reactive systems. A message-driven system is powered by means of asynchronous, non-blocking communication. This enables first and foremost isolation.

Frameworks

• Lagom
• Play

Companies

• Lightbend

TODO

• The Reactive Manifesto http://www.reactivemanifesto.org
• https://developers.redhat.com/blog/2017/06/30/5-things-to-know-about-reactive-programming
• ReactiveX http://reactivex.io
• https://github.com/ReactiveX/RxJava
• https://blog.takipi.com/reactive-streams-and-the-weird-case-of-back-pressure/
• http://www.reactive-streams.org
• RSocket - steaming message protocol with reactive extension/stream semantics https://github.com/rsocket/rsocket/blob/master/Motivations.md