Preface

One of my favorite quotes is

The future is already here—it’s just not very evenly distributed.

William Gibson, science fiction author

The essence of that quote is that new ideas and technology take a while to diffuse through a community and become widely adopted. A good example of the slow diffusion of ideas is the story of how I discovered microservices. It began in 2006, when, after being inspired by a talk given by an AWS evangelist, I started down a path that ultimately led to my creating the original Cloud Foundry. (The only thing in common with today’s Cloud Foundry is the name.) Cloud Foundry was a Platform-as-a-Service (PaaS) for automating the deployment of Java applications on EC2. Like every other enterprise Java application that I’d built, my Cloud Foundry had a monolith architecture consisting of a single Java Web Application Archive (WAR) file.

Bundling a diverse and complex set of functions such as provisioning, configuration, monitoring, and management into a monolith created both development and operations challenges. You couldn’t, for example, change the UI without testing and redeploying the entire application. And because the monitoring and management component relied on a Complex Event Processing (CEP) engine which maintained in-memory state we couldn’t run multiple instances of the application! That’s embarrassing to admit, but all I can say is that I am a software developer, and, “let he who is without sin cast the first stone.”