Why Flow Architectures Will Change How We Approach Systems Availability
Event-driven approaches to integration (such as what I describe in Flow Architectures: The Future of Streaming and Event-Driven Integration ) promise to change the way we solve a lot of problems in enterprise applications. Certainly the move to real time integration will change the speed at which we engage customers. However, an engineer named Scott Havens gave an interesting presentation at DevOps Enterprise a few years ago that opened my eyes to another interesting effect. One of the biggest challenges in distributed systems is managing the effects of dependencies on the functionality of the system as a whole. Take, for example, a web application that must return a value calculated from data provided by several external sources. Havens used the example of a retail inventory availability service. In a traditional service-oriented model, this task would be handled through a number of cascading service calls, starting with the service tasked with returning the final value, followed by