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I am thinking of building an application using a Service Oriented Architecture (SOA).

This architecture is not as complex and messy as a microservices solution (I think), but I am facing similar design problems. Imagine I have services of type ServiceA that send work to services of type ServiceB. I guess, if I use a queue, then load balancing will not be a problem (since consumers will take what they can handle from the queue). But queues tend to generate some bad asynchrony in the code that requires extra effort to fix. So, I was more inclined to use HTTP calls between services, using the efficient and amazing async/await feature of C#. But this generates issues on sharing the workload and detecting services that are saturated or dead.

So my questions are:

1. Is there a queue that supports some sort of async/await feature and that functions like an HTTP call that returns the result where you need it and not in some callback where you cannot continue your original execution flow?
2. How do I load-balance the traffic between services and detect nodes that are not suitable for new assignments when using HTTP? I mean, I can probably design something by myself from scratch, but there ought to be some standard way or library or framework to do that by now. The best I found online was this, but it is built for microservices, so I am not sure if I can use it without problems or overkills.

Update: I have now discovered this question, that also asks for awaitable queues: awaitable Task based queue ...and also discovered Kubernetes, Marathon, and the like.