Just a couple of thoughts on micro services, triggered by a German blog post on heise Developer. So let’s go …
I have read quite a few articles on micro services, and literally all of them were overly optimistic and just scratching the, of course, positive surface. The examples are usually just slightly more complex than “Hello World” and also completely focused on technical aspects. For a non-deep dive technical exercise these things are ok. But nobody should fool him- or herself: the real world is much more complex.
There is, by the way, a real déjà vu here for me. Many things sound remarkable similar to what was said ten years ago in the context of SOA (Service-Oriented Architecture). Then, also, things like modularity and increased agility were cited all the time. (Re-use was the other standard one, but that did not work in most cases.) So what is really different now? I honestly fail to see anything new.
Instead there are arguments, again remarkably similar to SOA, in favor of faster possibility to adopt, easier deployment of change, and smaller and less complex code. Well, they are wrong. The key here is complexity and what its consequences are. The core complexity comes from the business requirements and not the chosen technology or architecture. And no matter how you slice, dice, and re-arrange things – the business complexity simply stays. Your only chance for survival is to find a clever way to layer things in a manner that makes sense for your business.
You will find that there are things that lend themselves well to (micro) services and of course that is how they should be approached. But you do not really have to have a separate deployment unit for every Mickey Mouse service. Just apply common sense and also keep in mind that things are in constant flux anyway.
So instead of spending much time on micro services, I would rather recommend to think about ways, which ensure that your system/architecture can easily adjust. And from a business perspective that is, of course.