Calculates the rate for a counter field. This function can show the rate at which a counter changes. The result is returned in a field named _rate with the unit being events/second.
counterAsRate()
is often expected to be used as the
function parameter in a timeChart()
or
groupBy()
function.
Important
This function requires at least two points for calculating a rate. When
used in a Time Chart
, it is important to
have at least two points in each bucket.
This function expects the field to have monotonic increasing values over
time. If this is not the case no result is returned. Counters are often
reset at server restarts or deployments. Running rate over a reset would
not return a result. Using counterAsRate()
in a
timeChart()
returns a rate for each bucket where the
counter was not reset and nothing for the buckets where the counter was
reset.
Hide omitted argument names for this function
Omitted Argument NamesThe argument name for
field
can be omitted; the following forms of this function are equivalent:logscale SyntaxcounterAsRate("value")
and:
logscale SyntaxcounterAsRate(field="value")
These examples show basic structure only.
counterAsRate()
Examples
Show the rate of a counter over time:
timechart(function=counterasrate(counter))
Show the rate of a counter with one series for each host over time, displaying the rate as events per minute:
timechart(host, function=counterasrate(counter), unit="1/sec to 1/min")