"How NOT to Measure Latency" by Gil Tene

Doesn't this depend on how "tuned" your subcomponents are? If I had a system that's supposedly heavily optimized, I would simply start seeing the worst-case latency on a higher percentile, 99.9th and so forth. Gil Tene has an excellent talk[1] on this. [1] [VIDEO]

This topic always leads me to think about this great talk from Gil Tene on how NOT to measure latencies (basically, don't use averages!). [VIDEO] I'm also a huge fan of how Dormando showed latency distributions in one of his recent Memcached Extstore posts. The default is 95th percentile but you can change the percentile to what matters to you (i.e. 99th percentile if you ask me!). Scroll down to see what he did and play with it. [LINK]

This a life changing video by Gil Tene on this topic. Bottom line is because of the number requests to support a single customer "request", the high percentiles are the ones that actually matter. [VIDEO]

We use locust at work but I HIGHLY recommend wrk for a very robust yet simple load testing tool. [LINK] And of course, this talk by Gil Tene is fantastic if you're interested in load testing stats [VIDEO]

Gil Tene has an entire talk about this point called "How NOT to measure latency" ( [VIDEO] ). In many circumstances, a web service (either server or client) has large numbers of dependencies, so a user only has to hit 95th-percentile latency for one dependency to have their overall latency significantly hurt. In other words, users may encounter the "rare" bad case on a majority of requests. Thus, even higher percentiles should be tightly controlled in order to truly keep a web service's overall latency under control.

Worth watching is How NOT to Measure Latency: [VIDEO] The speaker Gil Tene is also the author of the HdrHistogram which addresses this articles point: [LINK]

The "how not to measure latency" talk by Gil Tene is another really good explanation of this topic: [VIDEO]

who cares about lower percentage tiers in the world of big data? what does the p30 or 50 even matter at large scale? See Gil Tene's talk on how not to measure latency. [VIDEO] What matters is what most of your customers will get - p99, p999, p9999, p100.