Highlatency

Highlatency, commonly called high latency, is a term used to describe a substantial delay between an input or request and the corresponding response in a computer system or network. It is typically quantified as latency or round-trip time (RTT) in milliseconds, representing the time taken for a packet to traverse the network and return, though one-way delay may be measured in some contexts. Highlatency can arise from physical distance, routing inefficiencies, congestion, processing delays in routers and servers, wireless quality issues, and retransmissions due to packet loss or errors. It affects interactive applications more than bulk data transfers, leading to sluggish web pages, delayed remote desktop sessions, lag in online games, and buffering in streaming media. In distributed systems, highlatency increases operation times, affects consensus, and can complicate replication and fault tolerance.

Latency is measured with tools such as ping and traceroute, and is often accompanied by jitter, the variability of delay. Some latency is unavoidable due to speed-of-light limits, but it can be mitigated through network design and caching. Common mitigation strategies include deploying servers closer to users (edge computing), using content delivery networks, optimizing routing, increasing bandwidth where possible, reducing protocol overhead, implementing quality-of-service, and employing caching and prefetching. In storage and databases, reducing disk and memory latency via faster hardware, better I/O scheduling, and query optimization also helps.

Highlatency is not inherently harmful if the system tolerates it, but it becomes problematic for latency-sensitive applications, where responsiveness is critical.