standard deviation (stddev
)
The standard deviation is a measure that is used to quantify the amount of variation or dispersion of a set of data values.
A low standard deviation indicates that the data points tend to be close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the data points are spread out over a wider range of values.
how to use
Use it in alerts like this:
alarm: my_alert
on: my_chart
lookup: stddev -1m unaligned of my_dimension
warn: $this > 1000
stdev
does not change the units. For example, if the chart units is requests/sec
, the standard
deviation will be again expressed in the same units.
It can also be used in APIs and badges as &group=stddev
in the URL.
Examples
Examining last 1 minute successful
web server responses: