README
¶
Dynamic histogram collector for Go
This library implements streaming counter with dynamic bucketing by value size.
Usage
c := dynhist.Collector{
BucketsLimit: 10,
}
src := rand.NewSource(1)
r := rand.New(src)
for i := 0; i < 10000; i++ {
c.Add(r.Float64())
}
fmt.Println(c.String())
// Output:
// [ min max] cnt total% (10000 events)
// [0.00 0.11] 1099 10.99% ..........
// [0.11 0.22] 1093 10.93% ..........
// [0.22 0.33] 1127 11.27% ...........
// [0.33 0.44] 1121 11.21% ...........
// [0.44 0.54] 999 9.99% .........
// [0.54 0.63] 964 9.64% .........
// [0.63 0.73] 953 9.53% .........
// [0.73 0.81] 841 8.41% ........
// [0.81 0.90] 797 7.97% .......
// [0.90 1.00] 1006 10.06% ..........
Documentation
¶
Overview ¶
Package dynhist implements dynamic histogram collector.
Index ¶
Examples ¶
Constants ¶
const DefaultBucketsLimit = 20
DefaultBucketsLimit is a default maximum number of buckets.
Variables ¶
This section is empty.
Functions ¶
func AvgWidth ¶
AvgWidth is a weight function to maintain equal width of all buckets.
Should fit for normally distributed data.
Example ¶
c := dynhist.Collector{
BucketsLimit: 10,
}
src := rand.NewSource(1)
r := rand.New(src)
for i := 0; i < 10000; i++ {
c.Add(r.Float64())
}
fmt.Println(c.String())
Output: [ min max] cnt total% (10000 events) [0.00 0.11] 1099 10.99% .......... [0.11 0.22] 1093 10.93% .......... [0.22 0.33] 1127 11.27% ........... [0.33 0.44] 1121 11.21% ........... [0.44 0.54] 999 9.99% ......... [0.54 0.63] 964 9.64% ......... [0.63 0.73] 953 9.53% ......... [0.73 0.81] 841 8.41% ........ [0.81 0.90] 797 7.97% ....... [0.90 1.00] 1006 10.06% ..........
func ExpWidth ¶
ExpWidth creates a weight function with exponential bucket width growing.
For exponentially distributed data, values of 1.2 for sumWidthPow and 1 for spacingPow should be a good fit. Increase sumWidthPow to widen buckets for lower values. Increase spacingPow to widen buckets for higher values.
Example ¶
c := dynhist.Collector{
BucketsLimit: 10,
WeightFunc: dynhist.ExpWidth(1.2, 0.9),
}
src := rand.NewSource(1)
r := rand.New(src)
for i := 0; i < 100000; i++ {
c.Add(r.ExpFloat64())
}
fmt.Println(c.String())
Output: [ min max] cnt total% (100000 events) [ 0.00 0.07] 6577 6.58% ...... [ 0.07 0.22] 13380 13.38% ............. [ 0.22 0.45] 16002 16.00% ................ [ 0.45 1.11] 31072 31.07% ............................... [ 1.11 1.77] 15975 15.97% ............... [ 1.77 2.78] 10737 10.74% .......... [ 2.78 4.37] 4993 4.99% .... [ 4.37 6.50] 1121 1.12% . [ 6.51 8.96] 134 0.13% [ 9.03 10.80] 9 0.01%
func LatencyWidth ¶
LatencyWidth is a weight function suitable for collecting latency information.
It makes wider buckets for higher values, narrow buckets for lower values.
Types ¶
type Collector ¶
type Collector struct {
sync.Mutex
// BucketsLimit limits total number of buckets used.
BucketsLimit int
// Bucket keeps total count.
Bucket
// Buckets is a list of available buckets.
Buckets []Bucket
// PrintSum enables printing of a summary value in a bucket.
PrintSum bool
// RawValues stores incoming events, disabled by default. Use non-nil value to enable.
RawValues []float64
// WeightFunc calculates weight of adjacent buckets with total available. Pair with minimal weight is merged.
// AvgWidth is used by default.
// See also LatencyWidth, ExpWidth.
WeightFunc func(b1, b2, bTot Bucket) float64
}
Collector groups and counts values by size using buckets.
func (*Collector) LoadFromRuntimeMetrics ¶ added in v1.2.0
func (c *Collector) LoadFromRuntimeMetrics(h *metrics.Float64Histogram)
LoadFromRuntimeMetrics replaces existing buckets with data from metrics.Float64Histogram.
func (*Collector) Percentile ¶
Percentile returns maximum boundary for a fraction of values.
Source Files