[liampulles]

This is building a SOA distributed monolith, which is kind of cutting off your nose to spite your face. I've been there - would not recommend.

It makes the system brittle, slow, and forces strong commitments that dependent services remain up (rolling releases with non breaking migrations, etc).

If I were to do it again, then I would first ensure that the infrastructure is there for inter-service communication to be done asynchronously, and that changes are eventually consistent. Maybe using a workflow manager like Camunda or Temporal. Or even just event choreography between services - either of those is better than a synchronous HTTP call chain of what will become 7 dependent services.

[tra3]

I agree that asynchrony would be a stronger technical solution, but it’s not the defining characteristic of SOA. They author mentions circuit breakers so seems like they did think about network resiliency.

Other then async what would make it less of a “distributed monolith”, can you say?

[liampulles]

I am using SOA out of place and I should not have included it in my comment - I agree.

I guess distributed monolith is a nebulous term, and I'm sure people have their own criteria. To me, the defining characteristic IS the size of that synchronous call chain. If to serve some of the public operations of your system you need to make a synchronous HTTP call that spans more than one service, then I consider those services to be too tightly coupled and the system is closer to being a distributed monolith then a set of independent services (I'd make an exception if the first service is an API gateway or is very explicitly a kind of middleware service, and not defining business logic).

The degree to which the system is a distributed monolith, and how much one should care about that fact or invest effort to steer away from it is a function of how big the biggest one of those call chains is. I don't have a binary definition, more of a sliding scale. The way to avoid sliding more into the direction of a distributed monolith (at least the way I reckon it) is to avoid making those call chains from the get go.

[tra3]

Thanks @liampulles, appreciate your insight. Going through the same exercise you've helped me crystallize my thoughts.