Latency requirements determines the degree of user satisfaction about the web service. Software development practices shall consider the end-to-end latency as one of user-oriented characteristics during the entire life-cycle of an application. Latency budget defines latency target and non-functional requirements for distributed systems.
Distributed systems involve various technologies and communication principles that bring overhead and latencies. The root cause of latencies varies from physical properties of the network to the quality of software components. The post discussed sources of latencies from the prism of infrastructure, protocol and application.