Building Microservices, 2nd Edition

Chapter 3. Splitting the Monolith

Many of you reading this book likely don’t have a blank slate on which to design your system, and even if you did, starting with microservices might not be a great idea, for reasons we explored in Chapter 1. Many of you will already have an existing system, perhaps some form of monolithic architecture, which you are looking to migrate to a microservice architecture.

In this chapter I’ll outline some first steps, patterns, and general tips to help you navigate the transition to a microservice architecture.

Have a Goal

Microservices are not the goal. You don’t “win” by having microservices. Adopting a microservice architecture should be a conscious decision, one based on rational decision making. You should be thinking of migrating to a microservice architecture only if you can’t find any easier way to move toward your end goal with your current architecture.

Without a clear understanding as to what you are trying to achieve, you could fall into the trap of confusing activity with outcome. I’ve seen teams obsessed with creating microservices without ever asking why. This is problematic in the extreme given the new sources of complexity that microservices can introduce.

Fixating on microservices rather than on the end goal also means you will likely stop thinking of other ways in which you might bring about the change you are looking for. For example, microservices can help you scale your system, but there are often a number of alternative scaling ...