Latency is the delay involved in a request and its response. A round trip reflects both network latency and service latency, so a slow response can arise outside the service as well as within it. section 1.2.2
In web applications, latency matters alongside other service requirements:
- Backend services aim for low and predictable latency, particularly for video streaming and online gaming. section 1.2
- Network latency depends on factors such as transmission medium, distance, router efficiency, and bandwidth; service latency can reflect I/O delays, garbage collection, pauses, context switching, and serialization costs. section 1.2.2
- Rust’s low-level hardware control, lack of a garbage collector or runtime, non-blocking I/O, and zero-cost abstractions are presented as contributors to low service latency. section 1.2.2
