The upside seems to be some mythical infinite scalability which will collapse under such positive feedback loops.
You can get away with hiring devs able to only debug their little micro empire so long as you can retain some super senior rockstar level folks able to see the big picture when it inevitably breaks down in production under load. These skills are becoming rarer by the day, when they used to be nearly table stakes for a “senior” dev.
Microservices have their place, but many times you can see that it’s simply developers saying “not my problem” to the actual hard business case things.
The real benefit of a microservice is that it's easier to see the interactions, because you can't call into some random and unexpected part of the codebase...or at least it's much harder to do something that's not noticeable like that.
In the end, it depends on your skillsets. Most developers can't deal with a lot of complexity, and a monolith is the simplest way to program. They also can't really deal with scale, and cost of learning how to build a real distributed system is high...and the chances you'll hit scale are low.
So instead people scale horizontally or vertically, with ridiculously complicated tools like k8. K8 basically exists outside of google because developers can't write scalable apps, whether monolithic or microservice-based.
This is the critical piece that many organisations miss.
Microservices are the bricks; but the customer needs those assembled into a house.
Also we need to have about 5x as many people graduating with formal classes in distributed computing as are now or have been for the last several decades and it's just ridiculous how many people have to learn this stuff on their own. Distributed debugging is really had when you don't understand the fundamental problems.
Or for that matter, how many default alive companies have more teams than customers?
The business I'm part of isn't really after "scalable" technology, so that might color my opinion, but a lot of the arguments for microservices I hear from my colleagues are actually benefits of modular programs. Those two have just become synonyms in their minds.
Well.. I mean that’s an entirely circular point. Maybe you mean something else? That you can individually deploy and roll back different functionality that belong to a team? There’s some appeal for operations yeah.
> but a lot of the arguments for microservices I hear from my colleagues are actually benefits of modular programs
Yes I mean from a development perspective a library call is far, far superior to an http call. It is much more performant and orders of magnitude easier to reason about since the caller and callee are running the same version of the code. That means that breaking changes is a refactor and single commit, whereas with a service boundary you need a whole migration.
You can’t avoid services altogether, like say external services like a payment portal by a completely different company. But to deliberately create more of these expensive boundaries for no reason, within the same small org or team, is madness, imo.
This decoupling-of-updates-across-a-call-boundary is one of the key reasons why I _prefer_ microservices. Monoliths _force_ you to update your caller and callee at the same time, which appears attractive when they are 1-1 but becomes prohibitively difficult when there are multiple callers of the same logic - changes take longer and longer to be approved, and you drift further from CD. Microservices allow you to gradually roll out a change across the company at an appropriate rate - the new logic can be provided at a different endpoint for early adopters, and other consumers can gradually migrate to it as they are encouraged or compelled to do so.
Similarly with updates to cross-cutting concerns. Say there's a breaking change to your logging or testing framework, or an encryption library, or something like that. You can force all your teams to down tools and to synchronize in collaborating on one monster commit to The Monolith that will update everything at once - or you can tell everyone to update their own microservices, at their own pace (but by a given deadline, if InfoSec so demands), without blocking each other. Making _and testing and deploying_ one large commit containing lots of changes is, counter-intuitively, much harder than making lots of small commits containing the same quantity of actual change - your IDE can find-and-replace easily across the monorepo, but most updates due to breaking changes require human intervention and cannot be scripted. The ability for different microservices within the same company to consume different versions of the same utility library at the same time (as they are gradually, independently, updated) is a _benefit_, not a drawback.
> a library call[...]is much more performant [...than] these expensive boundaries
I mean, no argument here - but latency tends to be excessively sought by developers, beyond the point of actual experience improvement. If it's your limiting factor, then by all means look for ways to improve it - but designing for fast development and deployment has paid far greater dividends, in my experience, than overly optimizing for latency.
It's possible to migrate method calls incrementally (create a new method or add a parameter). In large codebases, it's necessary to migrate incrementally. The techniques overlap those of changing an RPC method.
Unless I misunderstand something here, they say pretty early in the article that they didn't have autoscaling configured for the service in question and there is no indication they scaled up the number of replicas manually after the downtime to account for the accumulated backlog of requests. So, in my mind, of course there can be no infinite, or really any, scalability if the service isn't allowed to scale...
Using micro-services doesn't mean you're using individual repositories and projects for each one. The best approach I've seen is one repo, with inter-linked packages/assemblies (lingo can vary depending on the language).
A monolith with N libraries (instead of N microservices) work so much better in my experience. You avoid the networking overhead, and the complexity of reasoning about all the possible ways N microservices will behave when one or more microservices crash.
But I agree one should do monolith by default.
Have you pondered the likelihood that your IDE sucks?