Microservicios y sentido común

 A propósito de microservicios, comentados en otras recientes oportunidades, un par de observaciones de Mika Yeap en Medium. Aquí se menciona el monolito más como una antiguedad que como una aplicación que integra todo en un sólo ejecutable. Esto tiene más sentido y va en la dirección en la que los mocroservicios actúan, o deberían, cuando corresponda.

Una razón que Yeap reconoce es la escala. Arquitectura distribuida y microservicios para atender el crecimiento de elementos y operaciones en el sistema del que se trate. Pero al hablar de escala, habla de escala global, de decenas o centenas de millones de nodos participantes:

There’s a multitude of reasons you’d need to use distributed architecture when you get big enough. The catch is most of us will never get big enough. I mean, how close are you to Amazon’s numbers? Or how about Netflix? That’s what I thought.

Yeap recuerda que trabajar con microservicios no es simple, y requiere disponer antes una organización robusta, disciplinada, con conocimiento y recursos. Aún así, recomienda pasar a una arquitectura distribuida sólo cuando sea imprescindible, y conservar "el monolito" mientras sea viable: 

...it’s best to challenge this beast only if you’re prepared. Skills. Talent. Organization. You need lots of things in the right flavor to do this well. If you think you can show some engineers a couple keynotes then send them off to split all the things, you’re in for a nasty surprise. My team and I weren’t prepared, so I would know. I mean, what does a startup without product-market fit or money have to offer against microservices? Just a month’s supply of ramen to feed five people. In other words, not much but goodwill and some elbow grease. Which wasn’t enough.So as far as I’ve learned, you should only be building microservices if you’ve got a gigantic user base, or the resources to support the specialized development. And even in the first case, you don’t necessarily have to go distributed immediately. In fact, even AirBnB was powered by a monolith until just recently. A monolith written in Ruby on Rails, no less. And it seems to me that their product worked just fine.

Yet many people truly believe distributed architecture is a superior alternative to a monolithic one. People actually think they’re two equal solutions to the same problem. Which is absurd, since they’re actually solutions to different problems.

...Y recuerda que la arquitectura distribuida no es simple, en absoluto. Podemos decir que cada punto que merece foco en su implementación requiere soluciones complejas. Pone como ejemplo las transacciones distribuidas:

Microservices promise to solve all sorts of problems, depending on who you ask. When in reality, they only exacerbate them when you don’t know what you’re doing. How? Well, just two words can send chills down any microservice veteran’s spine: Distributed transactions. How’s that for a nightmare? I promise you, once you have to configure orchestration-based sagas just to update one property on a single object, you’ll be begging for a good old boring monolith.

En fin, microservicios suena genial, pero antes de emprenderlos, piense y haga números.