Microservices can be implemented in two different ways—synchronously and asynchronously. The approach refers to when the next task has to wait for the completion of the current task. To run tasks in parallel using code, we have to run a pool of threads and run tasks in the threads of the pool. The asynchronous approach is when you use non-blocking operations and a single thread performs multiple tasks. If an operation can't be completed, it returns a flag that means the task has not yet completed and we have to try to run it again later.
In the past, Rust developers used synchronous operations only, which meant that if we wanted to read data from a socket, we would have to block an executing thread. Modern operating systems have two approaches to avoid blocking—non-blocking input/output functions, and a scalable I/O event notification...