telegraf/plugins/serializers/prometheus/collection.go

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package prometheus
import (
"hash/fnv"
"sort"
"strconv"
"strings"
"time"
"github.com/gogo/protobuf/proto"
"github.com/influxdata/telegraf"
dto "github.com/prometheus/client_model/go"
)
const helpString = "Telegraf collected metric"
type MetricFamily struct {
Name string
Type telegraf.ValueType
}
type Metric struct {
Labels []LabelPair
Time time.Time
Scaler *Scaler
Histogram *Histogram
Summary *Summary
}
type LabelPair struct {
Name string
Value string
}
type Scaler struct {
Value float64
}
type Bucket struct {
Bound float64
Count uint64
}
type Quantile struct {
Quantile float64
Value float64
}
type Histogram struct {
Buckets []Bucket
Count uint64
Sum float64
}
type Summary struct {
Quantiles []Quantile
Count uint64
Sum float64
}
type MetricKey uint64
func MakeMetricKey(labels []LabelPair) MetricKey {
h := fnv.New64a()
for _, label := range labels {
h.Write([]byte(label.Name))
h.Write([]byte("\x00"))
h.Write([]byte(label.Value))
h.Write([]byte("\x00"))
}
return MetricKey(h.Sum64())
}
type Entry struct {
Family MetricFamily
Metrics map[MetricKey]*Metric
}
type Collection struct {
config FormatConfig
Entries map[MetricFamily]Entry
}
func NewCollection(config FormatConfig) *Collection {
cache := &Collection{
config: config,
Entries: make(map[MetricFamily]Entry),
}
return cache
}
func hasLabel(name string, labels []LabelPair) bool {
for _, label := range labels {
if name == label.Name {
return true
}
}
return false
}
func (c *Collection) createLabels(metric telegraf.Metric) []LabelPair {
labels := make([]LabelPair, 0, len(metric.TagList()))
for _, tag := range metric.TagList() {
// Ignore special tags for histogram and summary types.
switch metric.Type() {
case telegraf.Histogram:
if tag.Key == "le" {
continue
}
case telegraf.Summary:
if tag.Key == "quantile" {
continue
}
}
name, ok := SanitizeName(tag.Key)
if !ok {
continue
}
labels = append(labels, LabelPair{Name: name, Value: tag.Value})
}
if c.config.StringHandling != StringAsLabel {
return labels
}
addedFieldLabel := false
for _, field := range metric.FieldList() {
value, ok := field.Value.(string)
if !ok {
continue
}
name, ok := SanitizeName(field.Key)
if !ok {
continue
}
// If there is a tag with the same name as the string field, discard
// the field and use the tag instead.
if hasLabel(name, labels) {
continue
}
labels = append(labels, LabelPair{Name: name, Value: value})
addedFieldLabel = true
}
if addedFieldLabel {
sort.Slice(labels, func(i, j int) bool {
return labels[i].Name < labels[j].Name
})
}
return labels
}
func (c *Collection) Add(metric telegraf.Metric) {
labels := c.createLabels(metric)
for _, field := range metric.FieldList() {
metricName := MetricName(metric.Name(), field.Key, metric.Type())
metricName, ok := SanitizeName(metricName)
if !ok {
continue
}
family := MetricFamily{
Name: metricName,
Type: metric.Type(),
}
entry, ok := c.Entries[family]
if !ok {
entry = Entry{
Family: family,
Metrics: make(map[MetricKey]*Metric),
}
c.Entries[family] = entry
}
metricKey := MakeMetricKey(labels)
m, ok := entry.Metrics[metricKey]
if ok {
// A batch of metrics can contain multiple values for a single
// Prometheus sample. If this metric is older than the existing
// sample then we can skip over it.
if metric.Time().Before(m.Time) {
continue
}
}
switch metric.Type() {
case telegraf.Counter:
fallthrough
case telegraf.Gauge:
fallthrough
case telegraf.Untyped:
value, ok := SampleValue(field.Value)
if !ok {
continue
}
m = &Metric{
Labels: labels,
Time: metric.Time(),
Scaler: &Scaler{Value: value},
}
// what if already here
entry.Metrics[metricKey] = m
case telegraf.Histogram:
if m == nil {
m = &Metric{
Labels: labels,
Time: metric.Time(),
Histogram: &Histogram{},
}
}
switch {
case strings.HasSuffix(field.Key, "_bucket"):
le, ok := metric.GetTag("le")
if !ok {
continue
}
bound, err := strconv.ParseFloat(le, 64)
if err != nil {
continue
}
count, ok := SampleCount(field.Value)
if !ok {
continue
}
m.Histogram.Buckets = append(m.Histogram.Buckets, Bucket{
Bound: bound,
Count: count,
})
case strings.HasSuffix(field.Key, "_sum"):
sum, ok := SampleSum(field.Value)
if !ok {
continue
}
m.Histogram.Sum = sum
case strings.HasSuffix(field.Key, "_count"):
count, ok := SampleCount(field.Value)
if !ok {
continue
}
m.Histogram.Count = count
default:
continue
}
entry.Metrics[metricKey] = m
case telegraf.Summary:
if m == nil {
m = &Metric{
Labels: labels,
Time: metric.Time(),
Summary: &Summary{},
}
}
switch {
case strings.HasSuffix(field.Key, "_sum"):
sum, ok := SampleSum(field.Value)
if !ok {
continue
}
m.Summary.Sum = sum
case strings.HasSuffix(field.Key, "_count"):
count, ok := SampleCount(field.Value)
if !ok {
continue
}
m.Summary.Count = count
default:
quantileTag, ok := metric.GetTag("quantile")
if !ok {
continue
}
quantile, err := strconv.ParseFloat(quantileTag, 64)
if err != nil {
continue
}
value, ok := SampleValue(field.Value)
if !ok {
continue
}
m.Summary.Quantiles = append(m.Summary.Quantiles, Quantile{
Quantile: quantile,
Value: value,
})
}
entry.Metrics[metricKey] = m
}
}
}
func (c *Collection) Expire(now time.Time, age time.Duration) {
expireTime := now.Add(-age)
for _, entry := range c.Entries {
for key, metric := range entry.Metrics {
if metric.Time.Before(expireTime) {
delete(entry.Metrics, key)
if len(entry.Metrics) == 0 {
delete(c.Entries, entry.Family)
}
}
}
}
}
func (c *Collection) GetEntries(order MetricSortOrder) []Entry {
entries := make([]Entry, 0, len(c.Entries))
for _, entry := range c.Entries {
entries = append(entries, entry)
}
switch order {
case SortMetrics:
sort.Slice(entries, func(i, j int) bool {
lhs := entries[i].Family
rhs := entries[j].Family
if lhs.Name != rhs.Name {
return lhs.Name < rhs.Name
}
return lhs.Type < rhs.Type
})
}
return entries
}
func (c *Collection) GetMetrics(entry Entry, order MetricSortOrder) []*Metric {
metrics := make([]*Metric, 0, len(entry.Metrics))
for _, metric := range entry.Metrics {
metrics = append(metrics, metric)
}
switch order {
case SortMetrics:
sort.Slice(metrics, func(i, j int) bool {
lhs := metrics[i].Labels
rhs := metrics[j].Labels
if len(lhs) != len(rhs) {
return len(lhs) < len(rhs)
}
for index := range lhs {
l := lhs[index]
r := rhs[index]
if l.Name != r.Name {
return l.Name < r.Name
}
if l.Value != r.Value {
return l.Value < r.Value
}
}
return false
})
}
return metrics
}
func (c *Collection) GetProto() []*dto.MetricFamily {
result := make([]*dto.MetricFamily, 0, len(c.Entries))
for _, entry := range c.GetEntries(c.config.MetricSortOrder) {
mf := &dto.MetricFamily{
Name: proto.String(entry.Family.Name),
Help: proto.String(helpString),
Type: MetricType(entry.Family.Type),
}
for _, metric := range c.GetMetrics(entry, c.config.MetricSortOrder) {
l := make([]*dto.LabelPair, 0, len(metric.Labels))
for _, label := range metric.Labels {
l = append(l, &dto.LabelPair{
Name: proto.String(label.Name),
Value: proto.String(label.Value),
})
}
m := &dto.Metric{
Label: l,
}
if c.config.TimestampExport == ExportTimestamp {
m.TimestampMs = proto.Int64(metric.Time.UnixNano() / int64(time.Millisecond))
}
switch entry.Family.Type {
case telegraf.Gauge:
m.Gauge = &dto.Gauge{Value: proto.Float64(metric.Scaler.Value)}
case telegraf.Counter:
m.Counter = &dto.Counter{Value: proto.Float64(metric.Scaler.Value)}
case telegraf.Untyped:
m.Untyped = &dto.Untyped{Value: proto.Float64(metric.Scaler.Value)}
case telegraf.Histogram:
buckets := make([]*dto.Bucket, 0, len(metric.Histogram.Buckets))
for _, bucket := range metric.Histogram.Buckets {
buckets = append(buckets, &dto.Bucket{
UpperBound: proto.Float64(bucket.Bound),
CumulativeCount: proto.Uint64(bucket.Count),
})
}
if len(buckets) == 0 {
continue
}
m.Histogram = &dto.Histogram{
Bucket: buckets,
SampleCount: proto.Uint64(metric.Histogram.Count),
SampleSum: proto.Float64(metric.Histogram.Sum),
}
case telegraf.Summary:
quantiles := make([]*dto.Quantile, 0, len(metric.Summary.Quantiles))
for _, quantile := range metric.Summary.Quantiles {
quantiles = append(quantiles, &dto.Quantile{
Quantile: proto.Float64(quantile.Quantile),
Value: proto.Float64(quantile.Value),
})
}
if len(quantiles) == 0 {
continue
}
m.Summary = &dto.Summary{
Quantile: quantiles,
SampleCount: proto.Uint64(metric.Summary.Count),
SampleSum: proto.Float64(metric.Summary.Sum),
}
default:
panic("unknown telegraf.ValueType")
}
mf.Metric = append(mf.Metric, m)
}
if len(mf.Metric) != 0 {
result = append(result, mf)
}
}
return result
}