Synchronous Service-to-Service Calls and Their Failure Modes
One service calling another over the network and blocking until it answers: the caller's latency is the sum of the callees' latencies, and a callee that is down, slow, or times out becomes the caller's failure. After learning this a student can trace what happens to a request when the third of four downstream calls times out, and explain why retrying it risks doing the same work twice. That is the baseline against which handing the work to a broker is an improvement rather than an extra moving part.
Synchronous Versus Asynchronous Communication in Microservices
This concept covers the distinction between synchronous and asynchronous communication patterns in microservice architecture: synchronous communication is a pattern in which a calling service issues …