Immutable Infrastructure

Chapter 1. Here Then Gone: What Is Immutable Infrastructure?

You’re standing on the beach on a bright day. You look out. There’s a constant renewal of pointed, flashing light, here then gone, conveying energy, then ceasing to exist without any consequential decay. The sun automates an optical phenomenon on water in motion: glitter patterns that comprise millions of ephemeral glints. In applied optics, physicists who study the properties of light have long marveled at the Phoenix-like effect we see. Back on the beach, other glints are immediately visible, carrying out the same energetic tasks, then gone. No decay.

It’s an imperfect, but provocative, analogy: machines in a data center seem like a far cry from points of natural, strobed light—not least because we relate to them as physical items rather than as organized energy, as long-lived rather than as ephemeral. We tend to rack machines in an n-tier framework in our minds to a greater or lesser degree, instead of thinking in terms of distributed, abstracted instances or resources capable of spanning multiple availability zones in cloud computing. But when infrastructure becomes code, resources are, in fact, more akin to those glints on the sea than to dedicated boxes.

Toward Cloud Thinking

For decades, we’ve mulled over basic questions around how we provision machine resources—and those questions are under new scrutiny with cloud computing. The techniques we’ve traditionally used to manage machines struggle in distributed, ...