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diff --git a/web/api/queries/median/README.md b/web/api/queries/median/README.md new file mode 100644 index 0000000..25ce8b8 --- /dev/null +++ b/web/api/queries/median/README.md @@ -0,0 +1,45 @@ +<!-- +title: "Median" +description: "Use median in API queries and health entities to find the 'middle' value from a sample, eliminating any unwanted spikes in the returned metrics." +custom_edit_url: https://github.com/netdata/netdata/edit/master/web/api/queries/median/README.md +--> + +# Median + +The median is the value separating the higher half from the lower half of a data sample +(a population or a probability distribution). For a data set, it may be thought of as the +"middle" value. + +`median` is not an accurate average. However, it eliminates all spikes, by sorting +all the values in a period, and selecting the value in the middle of the sorted array. + +## how to use + +Use it in alarms like this: + +``` + alarm: my_alarm + on: my_chart +lookup: median -1m unaligned of my_dimension + warn: $this > 1000 +``` + +`median` does not change the units. For example, if the chart units is `requests/sec`, the result +will be again expressed in the same units. + +It can also be used in APIs and badges as `&group=median` in the URL. + +## Examples + +Examining last 1 minute `successful` web server responses: + +-  +-  +-  +-  + +## References + +- <https://en.wikipedia.org/wiki/Median>. + +[](<>) |