p95latens

p95latens is a performance metric used to describe the latency experienced by the 95th percentile of operations or requests within a system. Latency refers to the time it takes for a request to be processed and a response to be returned. While average latency provides a general idea of system performance, it can be misleading if a few very slow operations disproportionately affect the average. p95latens, on the other hand, focuses on the tail end of the latency distribution.

By measuring the 95th percentile, p95latens indicates the latency experienced by most users or requests, excluding the slowest 5%. This metric is valuable because it helps identify and address performance issues that might be hidden by averaging. For example, a system might have a low average latency but a very high p95latens, suggesting that a small but significant portion of requests are experiencing unacceptable delays. This can lead to poor user experience and potential service degradation.

Understanding and monitoring p95latens is crucial for system administrators, developers, and SREs (Site Reliability Engineers) to ensure a consistent and acceptable level of performance. It aids in capacity planning, troubleshooting, and setting performance benchmarks. When p95latens starts to increase, it signals a potential problem that requires investigation, such as overloaded resources, inefficient algorithms, or network bottlenecks.