Skip to content

Commit

Permalink
refactor prometheus exporter to slightly improve performance (#3351)
Browse files Browse the repository at this point in the history
  • Loading branch information
@dashpole
dashpole committed Oct 20, 2022
1 parent 587437b commit 1133977
Showing 1 changed file with 35 additions and 94 deletions.
129 changes: 35 additions & 94 deletions exporters/prometheus/exporter.go
View file
Expand Up @@ -52,7 +52,7 @@ type collector struct {

disableTargetInfo bool
withoutUnits bool
targetInfo *metricData
targetInfo prometheus.Metric
createTargetInfoOnce sync.Once
}

Expand Down Expand Up @@ -105,74 +105,39 @@ func (c *collector) Collect(ch chan<- prometheus.Metric) {
}
}

for _, metricData := range c.getMetricData(metrics) {
if metricData.valueType == prometheus.UntypedValue {
m, err := prometheus.NewConstHistogram(metricData.description, metricData.histogramCount, metricData.histogramSum, metricData.histogramBuckets, metricData.attributeValues...)
if err != nil {
otel.Handle(err)
continue
}
ch <- m
} else {
m, err := prometheus.NewConstMetric(metricData.description, metricData.valueType, metricData.value, metricData.attributeValues...)
if err != nil {
otel.Handle(err)
continue
}
ch <- m
}
}
}

// metricData holds the metadata as well as values for individual data points.
type metricData struct {
// name should include the unit as a suffix (before _total on counters)
// see https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/data-model.md#metric-metadata-1
name string
description *prometheus.Desc
attributeValues []string
valueType prometheus.ValueType
value float64
histogramCount uint64
histogramSum float64
histogramBuckets map[float64]uint64
}

func (c *collector) getMetricData(metrics metricdata.ResourceMetrics) []*metricData {
allMetrics := make([]*metricData, 0)

c.createTargetInfoOnce.Do(func() {
// Resource should be immutable, we don't need to compute again
c.targetInfo = c.createInfoMetricData(targetInfoMetricName, targetInfoDescription, metrics.Resource)
targetInfo, err := c.createInfoMetric(targetInfoMetricName, targetInfoDescription, metrics.Resource)
if err != nil {
// If the target info metric is invalid, disable sending it.
otel.Handle(err)
c.disableTargetInfo = true
}
c.targetInfo = targetInfo
})

if c.targetInfo != nil {
allMetrics = append(allMetrics, c.targetInfo)
if !c.disableTargetInfo {
ch <- c.targetInfo
}

for _, scopeMetrics := range metrics.ScopeMetrics {
for _, m := range scopeMetrics.Metrics {
switch v := m.Data.(type) {
case metricdata.Histogram:
allMetrics = append(allMetrics, getHistogramMetricData(v, m, c.getName(m))...)
addHistogramMetric(ch, v, m, c.getName(m))
case metricdata.Sum[int64]:
allMetrics = append(allMetrics, getSumMetricData(v, m, c.getName(m))...)
addSumMetric(ch, v, m, c.getName(m))
case metricdata.Sum[float64]:
allMetrics = append(allMetrics, getSumMetricData(v, m, c.getName(m))...)
addSumMetric(ch, v, m, c.getName(m))
case metricdata.Gauge[int64]:
allMetrics = append(allMetrics, getGaugeMetricData(v, m, c.getName(m))...)
addGaugeMetric(ch, v, m, c.getName(m))
case metricdata.Gauge[float64]:
allMetrics = append(allMetrics, getGaugeMetricData(v, m, c.getName(m))...)
addGaugeMetric(ch, v, m, c.getName(m))
}
}
}

return allMetrics
}

func getHistogramMetricData(histogram metricdata.Histogram, m metricdata.Metrics, name string) []*metricData {
func addHistogramMetric(ch chan<- prometheus.Metric, histogram metricdata.Histogram, m metricdata.Metrics, name string) {
// TODO(https://github.com/open-telemetry/opentelemetry-go/issues/3163): support exemplars
dataPoints := make([]*metricData, 0, len(histogram.DataPoints))
for _, dp := range histogram.DataPoints {
keys, values := getAttrs(dp.Attributes)
desc := prometheus.NewDesc(name, m.Description, keys, nil)
Expand All @@ -183,60 +148,47 @@ func getHistogramMetricData(histogram metricdata.Histogram, m metricdata.Metrics
cumulativeCount += dp.BucketCounts[i]
buckets[bound] = cumulativeCount
}
md := &metricData{
name: m.Name,
description: desc,
attributeValues: values,
valueType: prometheus.UntypedValue,
histogramCount: dp.Count,
histogramSum: dp.Sum,
histogramBuckets: buckets,
m, err := prometheus.NewConstHistogram(desc, dp.Count, dp.Sum, buckets, values...)
if err != nil {
otel.Handle(err)
continue
}
dataPoints = append(dataPoints, md)
ch <- m
}
return dataPoints
}

func getSumMetricData[N int64 | float64](sum metricdata.Sum[N], m metricdata.Metrics, name string) []*metricData {
func addSumMetric[N int64 | float64](ch chan<- prometheus.Metric, sum metricdata.Sum[N], m metricdata.Metrics, name string) {
valueType := prometheus.CounterValue
if !sum.IsMonotonic {
valueType = prometheus.GaugeValue
}
dataPoints := make([]*metricData, 0, len(sum.DataPoints))
for _, dp := range sum.DataPoints {
if sum.IsMonotonic {
// Add _total suffix for counters
name += counterSuffix
}
keys, values := getAttrs(dp.Attributes)
desc := prometheus.NewDesc(name, m.Description, keys, nil)
md := &metricData{
name: m.Name,
description: desc,
attributeValues: values,
valueType: valueType,
value: float64(dp.Value),
m, err := prometheus.NewConstMetric(desc, valueType, float64(dp.Value), values...)
if err != nil {
otel.Handle(err)
continue
}
dataPoints = append(dataPoints, md)
ch <- m
}
return dataPoints
}

func getGaugeMetricData[N int64 | float64](gauge metricdata.Gauge[N], m metricdata.Metrics, name string) []*metricData {
dataPoints := make([]*metricData, 0, len(gauge.DataPoints))
func addGaugeMetric[N int64 | float64](ch chan<- prometheus.Metric, gauge metricdata.Gauge[N], m metricdata.Metrics, name string) {
for _, dp := range gauge.DataPoints {
keys, values := getAttrs(dp.Attributes)
desc := prometheus.NewDesc(name, m.Description, keys, nil)
md := &metricData{
name: m.Name,
description: desc,
attributeValues: values,
valueType: prometheus.GaugeValue,
value: float64(dp.Value),
m, err := prometheus.NewConstMetric(desc, prometheus.GaugeValue, float64(dp.Value), values...)
if err != nil {
otel.Handle(err)
continue
}
dataPoints = append(dataPoints, md)
ch <- m
}
return dataPoints
}

// getAttrs parses the attribute.Set to two lists of matching Prometheus-style
Expand Down Expand Up @@ -268,21 +220,10 @@ func getAttrs(attrs attribute.Set) ([]string, []string) {
return keys, values
}

func (c *collector) createInfoMetricData(name, description string, res *resource.Resource) *metricData {
if c.disableTargetInfo {
return nil
}

func (c *collector) createInfoMetric(name, description string, res *resource.Resource) (prometheus.Metric, error) {
keys, values := getAttrs(*res.Set())

desc := prometheus.NewDesc(name, description, keys, nil)
return &metricData{
name: name,
description: desc,
attributeValues: values,
valueType: prometheus.GaugeValue,
value: float64(1),
}
return prometheus.NewConstMetric(desc, prometheus.GaugeValue, float64(1), values...)
}

func sanitizeRune(r rune) rune {
Expand Down

0 comments on commit 1133977

Please sign in to comment.