Several indicators of statsd timer

  statsd

Indicator list

Such as 450 120 553 994 334 844 675 496
(120 334 450 496 553 675 844 994)

count

count of the items processed
The total number is 8 here.

max/upper

The largest value

The maximum value, here is 994

min/lower

The smallest value

Minimum value, here is 120

sum

Total of items

The sum total, here is 4466

mean

average of the items

The average value here is 558.25

sum_90

The sum of values up to the 90th percentile

In ascending order of size, the sum of the first 90% data, here is 3472 (4466-994)

upper_90

The upper value of the 90th percentile group

In ascending order of size, the largest number in the first 90% data, here is 844

mean_90

The average of values up to the 90th percentile

In ascending order of size, the average value of the first 90% data, here is 496

90thPercentile

A group of n observation values are arranged according to the numerical value, and the value at the p% position is called the p hundredth digit. Percentile is usually expressed by the hundredth percentile, such as the fifth percentile, which means that the cumulative frequency of measured values is 5% in all measured data.

Percentile provides information about how each data item is distributed between the minimum and maximum values. For data without a large number of repetitions, the p percentile divides it into two parts. About p% of data items have values smaller than the p percentile; While about (100-p)% of the data items have values greater than the p percentile.
90% response time, which means, for example, 90% response time in an hour is 500ms, indicating that 90% of the response time for all requests for the page in this hour is less than or equal to 500 ms.

  • Calculation method

Let a sequence be supplied with n numbers and require (k%) percent:
(1) sort from small to large, find (n-1)*k%, remember the integer part as I, decimal part as j (Here 7*0.9=6.3, I is 6, and j is 0.3)
(2) the result = (1-j)Number (i+1)+jNumber (i+2) (here 0.7844+0.3994=889)
Pay special attention to the following two most likely situations:
(1)j is 0, that is, (n-1)*k% is exactly an integer, then the result is exactly the (i+1) th number
(2) The (i+1) th number is equal to the (i+2) th number, which is known without calculation.

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