add_sample(sample, value [, size])

This function allows you to store data samples which are represented as time series and then query statistics.

sample Name of the sample. If it does not exist, a new sample with this name will be created

value Value which will be added to the sample as one data point

size Optional size of sample. In this case, the sample works like a moving window adding the new element to the end and removing the first element in the sample if max size is reached