Run! The Distributed Systems are coming!

You can avoid the fate of those that fell before you

This is a letter to my fellow engineers, specifically those who operate in the front-end world. This letter is sent with love, but carries a message of deep foreboding. It is a warning and yet it is a message of hope, that there is a chance to maintain peace and happiness in your work life.

This letter is inspired by a question recently posed by the talented Andy Pimlett – with whom I had the pleasure of serving alongside the lovely people of Mando. See Andy Pimlett on LinkedIn: JavaScript Front-End Architecture. Therein Andy poses a question that has been keeping my mind in constant churn: ‘what does the line between the UI and the backend platform look like now?’. More importantly to me however is raising awareness of the quite frankly ridiculous levels of complexity that hide behind the innocent term ‘Microservices’, as I shall lay out here…

Lurking in your Jam

The devil doesn’t come dressed in a red cape and pointy horns. He comes as everything you’ve ever wished for.

Tucker Max – Apparently

Jamstack is exactly the sort of revolution the front-end world has desperately needed for too long. It promises to reduce the long-standing pain resulting from complexity and bloat that has emerged out of the constant over-engineering introduced by well intending technologies such as npm, React and Angular.

I’ll not cover the ‘Client’ end definition of Jamstack as there are plenty of perfectly good resources for that already including the Jamstack website itself: To be absolutely clear on my position here, I have been blown away by the power of Jamstack. This really is the tech that the web needs now. You want to put your money into new web technology? I’m telling you it is Jamstack and its global community; Web3 can get in the bin (really, forget Web3, it’s another last-ditch Ponzi-scheme from the crypto bros to try and keep their awful blockchain investments on life-support for another year).

That said, the threat to your peace and happiness that I wish to warn you about lies, unbeknownst to many, innocently nestled away in a corner of a diagram featured in many of the Jamstack articles, videos and websites that talk about this otherwise wonderful new technology:

Buried in these tempting looking simple diagrams lies a terrible, terrible beast that wears a red coat and charges through your peaceful villages shooting anyone who fails to kneel before the might of the King.

(Let’s forget for a moment that all the diagram shows is that the app server on down has been moved into a small little innocent tidy-looking box alongside CDN)

A Microservice by any other name will be just as difficult

Scenario: You’re building an application… You are writing some logic that calls a method on a class in another area of the application.

Question: Would calling the method be much improved by sending it on a trip along a network?

The only sensible answer, surely, would be: “are you mad?”. And, yet, here we are, some 10 years on since the term ‘Microservice’ was first bandied about, with half the planet decomposing their applications into separate ‘Microservices ‘ and having them directly call each other synchronously across a network. This antipattern now even has its own name: ‘distributed monolith’ and it is known to give all the pain of a monolith plus the pain of a distributed system and basically none of the benefits.

Why would anyone willingly triple the complexity of an application for no tangible benefit? Well… first of all… I guess… we’re social creatures, if our peers and those we look up to are doing something then we naturally take an interest. If everyone in your industry is talking about a thing then it becomes so well known that you may even be getting pressure from your boss or clients to do that thing.

Secondly… we’re techies, nerds, geeks, we like the challenging things. Hey, if Netflix do it and it gives them great results then the complexity must be worth it and it will feel great to wield complexity and win fortune for the business!

Finally, I think the name has a lot to do with it. How much harm can come from something called a ‘microservice’? Well, would you willingly embark on the path of a Service Oriented Architecture for your UI tier? Because that is what you are doing  whether you realise it or not. Microservices are a slant on the classic ‘Distributed System Architecture’. It has all, if not more, of the complexity of your classic Distributed System, but the name ‘microservice’ doesn’t really give you that feeling. Sure a Microservice must be an easy service, easy to deploy, easy to build, easy to integrate? No. No. No. Read on…

Distributed Systems destroyed my technical career

If ever there was a clear way to demonstrate how complicated Distributed Systems really are, it lies in my career trajectory. During the first half of my career I always imagined I was destined to become a technical architect. That is until I encountered technical architecture in Distributed Systems design. Now I am a hands-off manager. I find that managing teams of people and managing projects with all of the pressures and complexities that come with those responsibilities is far easier and more rewarding than programming Distributed Systems. But of course some people love this stuff! I’m not saying it is bad or a terrible choice, just that I do not have the technical chops to survive a career in this area and I don’t consider myself to be very dim. I certainly wouldn’t want to wander into this quagmire by accident!

So, what, exactly, are you trying to protect me from?

I get it, by now you’re probably sick of hearing me describing how difficult I find Distributed Systems. So let me tell what I know that engineers must know to be able to deliver effective Distributed Systems, or Microservices, or SOA, or Cloud Native Architecture, or MACH or whatever you want to call it – they all have the same fundamental concerns.

  1. Loosely coupled architecture – You need it. Its numero uno for any distributed system. Without it you have a distributed monolith which isn’t a distributed system at all. Loosely coupled means embracing asynchrony and with that comes eventual consistency, which your application must also embrace. Asynchrony is different from ‘async’ calls. Instead your tools in this space include message queues, service buses and brokers – more specifically for cloud native you will include events and streams.
  2. SRE – Distributed Systems are so complex that the industry consensus is that you should assume your system is in a failure state and go from there. I’m not even kidding. See Software Reliability Engineering, you will likely need someone skilled in this on your engineering and operational teams. You need to make sure your system is consistent, available and durable. This really is a career path in its own right!
  3. Deployment Strategies – You need to be able to safely update your microservices, components and so on without disrupting service. See the Google DORA research in this area for the different strategies you will need to familiarise yourself with:
  4. Observability: Modern cloud native systems will often have hundreds of components interacting with each other to achieve common business goals. How do you know if the system is healthy or not? How do you know the lifecycle of your customer’s data through your system for compliance with data protection standards? Enter Application Performance Monitoring and Distributed Tracing. See:

Hey, I would always default to a single application until such time that the technical demands necessitate decoupling. Monoliths are NOT a dirty word, they have many benefits in terms of maintainability. A helpful rule here is thus: if your components need to call each other directly to achieve their goals then keep them together in a monolith and save yourself a world of pain. Most UIs that call down into a distributed architecture will probably be fine with a single UI aggregation tier or at most BFFs (Sam Newman) Introducing loosely coupled architectures into your UI strikes me as a one-way trip to pain.

Your options have been laid before you…

Know that it is not a technical decision, it is a business decision and often closely tied to your business architecture.

It is too late for many of us in backend/platform engineering but I am worried for those of you responsible for client tier architecture. The concept of ‘Microservices’ is a creeping menace and I hope that these lessons serve to protect your sanity and stress levels.

So don’t feel pressured into a Distributed Architecture just because it’s a name you’ve heard (Microservices, MACH) or part of a wider architecture that you already get some benefits from (i.e. Jamstack). Just be aware that those little boxes on those diagrams belie decades of computer science that will likely never become as simple as the tempting diagrams want you to believe.

Understand whether you truly need microservices and avoid them if at all possible! But! But just because I struggle to imagine many scenarios where a UI tier would warrant a distributed architecture does not mean you don’t need it. Netflix and Amazon need it but so do some smaller businesses. Hell, my current employer has carefully considered its technical strategy, weighed the pros and cons and has decided that the increase in complexity of a distributed system is worth it for their commercial strategy. Know that it is not a technical decision, it is a business decision and often closely tied to your business architecture.

If you wish to stand and fight then be prepared to wield your weapons of Loosely Coupled Architecture, SRE, Deployment Strategy and Observability. But be sure, no one will blame you should you choose to consolidate your efforts in something far simpler; something that protects your daily life, bringing joy to you and your customers.

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