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A comment on We built network isolation for 1500 services. Parent comment

Re:We built network isolation for 1500 services by p10jkle on Tuesday November 05, 2019 @02:32PM (#21455791)
The common idea is that if you have to regularly roll out all your services, then you still basically have a monolith. So if you have a lot of shared code in libaries, there are no benefits to microservices. In our case, maybe we do have core libaries like to read from Cassandra, but you don't necessarily have to roll out everything if you improve them. Some pods could be even a year old

All the services have their own keyspace in Cassandra, there is near-zero cross service data access

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Re:We built network isolation for 1500 services by virgilp on Wednesday November 06, 2019 @03:44AM (#21460726)
That's not what makes a distributed monolith, IMO. Or to put it differently, it's not what makes a "monolith" be equal to "bad" in people minds. You want to avoid the badness, don't want to avoid the label.

So, what is bad about a monolith? The complexity. Coupling of unrelated things; because it's simple to do so, because it's right there next to you and you know how it's implemented and what it performs, so you do thing A in component X knowing/relying on the fact that component Y will do the thing B, because that's how it's implemented (not because it's inherent unavoidable business logic).

How do you end up with a distributed monolith? E.g. assume that microservice B will call microservice C only after you (i.e. microservice A) had a chance to call C first. Yes your code is distributed, but you don't get the benefit of logic segregation between the modules - you just get all the downsides of distributed systems.

Do note that my scenario requires no shared code or library. Not sharing code doesn't save you from the distributed monolith - careful thought does.

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Re:We built network isolation for 1500 services by jacquesm on Wednesday November 06, 2019 @04:20AM (#21460907)
Amen. Lots of micro service engineering is at the level of cargo cults and label avoidance. There are companies that do it well but relatively few of those. Whether TFA is a good or a bad example can not be told from the article contents, it would need a lot more information.
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