[ajmurmann]

That's a totally bizarre definition. Having worked on a high-performance in-memory data grid for the last eight years, I can guarantee that you'll get all the fun distributed systems problems even with a single code base. That definition also excludes pretty much all famous distributed systems like most databases, messaging systems like Kafka and Rabbit etc.

What you seem to be getting at, isn't distributed systems, but the totally self-inflicted pain of a service oriented architecture

[vidarh]

> Having worked on a high-performance in-memory data grid for the last eight years, I can guarantee that you'll get all the fun distributed systems problems even with a single code base.

Having spent the last 28 years building distributed network-connected systems, this comes across as wildly obtuse.

The point is that there are orders of magnitude differences in complexity when scaling a system with few communications paths and little distribution of state across process or network boundaries as there is when scaling one with many paths and state distributed in many locations. We don't tend to start talking about distributed systems when you have a tiered stack of a horizontally scalable component sandwiched between a load balancer and a database even though in a very strict technical sense already that is "distributed".

Once you start adding message queues etc., then it certainly becomes more and more reasonable to talk about a distributed system, but there is there as well a distinct grey area if dealing with e.g. queues just triggering jobs in the same code base against the same database with respect to the intent clearly expressed by the original comment.

Put another way, ignore the word "distributed", re-read the original comment, and consider that irrespective of which label you're comfortable with, what the comment is doing is drawing a distinction between two classes of systems with wildly different complexity in the distribution of responsibility and state. Where precisely you draw the line is entirely irrelevant.

> What you seem to be getting at, isn't distributed systems, but the totally self-inflicted pain of a service oriented architecture

No, it really was not. This separation between basic 2/3 tier apps and systems with a more complex data flow pre-dates the SOA buzzword literally by decades.

[ajmurmann]

Maybe the distinction here would be one of which scope the respective maintainer cares about. For Shopify MySQL is mostly a black box, they don't need to re-implement their own atomic commit protocol, network partition detection etc., since MySQL did that for them. Implementors of MySQL did have to solve these distributed systems problems though and pick their CAP trade-offs, but I guess that's not the scope Shopify cares about here.