statsd_exporter/exporter.go
Wangchong Zhou 05bca84294
Implement listener for Unixgram sockets
As requested in #189

Signed-off-by: Wangchong Zhou <fffonion@gmail.com>
2019-04-05 16:45:34 -07:00

735 lines
20 KiB
Go

// Copyright 2013 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"bufio"
"bytes"
"encoding/binary"
"fmt"
"hash/fnv"
"io"
"net"
"regexp"
"sort"
"strconv"
"strings"
"time"
"unicode/utf8"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/log"
"github.com/prometheus/common/model"
"github.com/prometheus/statsd_exporter/pkg/clock"
"github.com/prometheus/statsd_exporter/pkg/mapper"
)
const (
defaultHelp = "Metric autogenerated by statsd_exporter."
regErrF = "A change of configuration created inconsistent metrics for " +
"%q. You have to restart the statsd_exporter, and you should " +
"consider the effects on your monitoring setup. Error: %s"
)
var (
illegalCharsRE = regexp.MustCompile(`[^a-zA-Z0-9_]`)
hash = fnv.New64a()
strBuf bytes.Buffer // Used for hashing.
intBuf = make([]byte, 8)
)
func labelNames(labels prometheus.Labels) []string {
names := make([]string, 0, len(labels))
for labelName := range labels {
names = append(names, labelName)
}
sort.Strings(names)
return names
}
// hashNameAndLabels returns a hash value of the provided name string and all
// the label names and values in the provided labels map.
//
// Not safe for concurrent use! (Uses a shared buffer and hasher to save on
// allocations.)
func hashNameAndLabels(name string, labels prometheus.Labels) uint64 {
hash.Reset()
strBuf.Reset()
strBuf.WriteString(name)
hash.Write(strBuf.Bytes())
binary.BigEndian.PutUint64(intBuf, model.LabelsToSignature(labels))
hash.Write(intBuf)
return hash.Sum64()
}
type CounterContainer struct {
// metric name
Elements map[string]*prometheus.CounterVec
}
func NewCounterContainer() *CounterContainer {
return &CounterContainer{
Elements: make(map[string]*prometheus.CounterVec),
}
}
func (c *CounterContainer) Get(metricName string, labels prometheus.Labels, help string) (prometheus.Counter, error) {
counterVec, ok := c.Elements[metricName]
if !ok {
counterVec = prometheus.NewCounterVec(prometheus.CounterOpts{
Name: metricName,
Help: help,
}, labelNames(labels))
if err := prometheus.Register(counterVec); err != nil {
return nil, err
}
c.Elements[metricName] = counterVec
}
return counterVec.GetMetricWith(labels)
}
func (c *CounterContainer) Delete(metricName string, labels prometheus.Labels) {
if _, ok := c.Elements[metricName]; ok {
c.Elements[metricName].Delete(labels)
}
}
type GaugeContainer struct {
Elements map[string]*prometheus.GaugeVec
}
func NewGaugeContainer() *GaugeContainer {
return &GaugeContainer{
Elements: make(map[string]*prometheus.GaugeVec),
}
}
func (c *GaugeContainer) Get(metricName string, labels prometheus.Labels, help string) (prometheus.Gauge, error) {
gaugeVec, ok := c.Elements[metricName]
if !ok {
gaugeVec = prometheus.NewGaugeVec(prometheus.GaugeOpts{
Name: metricName,
Help: help,
}, labelNames(labels))
if err := prometheus.Register(gaugeVec); err != nil {
return nil, err
}
c.Elements[metricName] = gaugeVec
}
return gaugeVec.GetMetricWith(labels)
}
func (c *GaugeContainer) Delete(metricName string, labels prometheus.Labels) {
if _, ok := c.Elements[metricName]; ok {
c.Elements[metricName].Delete(labels)
}
}
type SummaryContainer struct {
Elements map[string]*prometheus.SummaryVec
mapper *mapper.MetricMapper
}
func NewSummaryContainer(mapper *mapper.MetricMapper) *SummaryContainer {
return &SummaryContainer{
Elements: make(map[string]*prometheus.SummaryVec),
mapper: mapper,
}
}
func (c *SummaryContainer) Get(metricName string, labels prometheus.Labels, help string, mapping *mapper.MetricMapping) (prometheus.Observer, error) {
summaryVec, ok := c.Elements[metricName]
if !ok {
quantiles := c.mapper.Defaults.Quantiles
if mapping != nil && mapping.Quantiles != nil && len(mapping.Quantiles) > 0 {
quantiles = mapping.Quantiles
}
objectives := make(map[float64]float64)
for _, q := range quantiles {
objectives[q.Quantile] = q.Error
}
summaryVec = prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: metricName,
Help: help,
Objectives: objectives,
}, labelNames(labels))
if err := prometheus.Register(summaryVec); err != nil {
return nil, err
}
c.Elements[metricName] = summaryVec
}
return summaryVec.GetMetricWith(labels)
}
func (c *SummaryContainer) Delete(metricName string, labels prometheus.Labels) {
if _, ok := c.Elements[metricName]; ok {
c.Elements[metricName].Delete(labels)
}
}
type HistogramContainer struct {
Elements map[string]*prometheus.HistogramVec
mapper *mapper.MetricMapper
}
func NewHistogramContainer(mapper *mapper.MetricMapper) *HistogramContainer {
return &HistogramContainer{
Elements: make(map[string]*prometheus.HistogramVec),
mapper: mapper,
}
}
func (c *HistogramContainer) Get(metricName string, labels prometheus.Labels, help string, mapping *mapper.MetricMapping) (prometheus.Observer, error) {
histogramVec, ok := c.Elements[metricName]
if !ok {
buckets := c.mapper.Defaults.Buckets
if mapping != nil && mapping.Buckets != nil && len(mapping.Buckets) > 0 {
buckets = mapping.Buckets
}
histogramVec = prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: metricName,
Help: help,
Buckets: buckets,
}, labelNames(labels))
if err := prometheus.Register(histogramVec); err != nil {
return nil, err
}
c.Elements[metricName] = histogramVec
}
return histogramVec.GetMetricWith(labels)
}
func (c *HistogramContainer) Delete(metricName string, labels prometheus.Labels) {
if _, ok := c.Elements[metricName]; ok {
c.Elements[metricName].Delete(labels)
}
}
type Event interface {
MetricName() string
Value() float64
Labels() map[string]string
MetricType() mapper.MetricType
}
type CounterEvent struct {
metricName string
value float64
labels map[string]string
}
func (c *CounterEvent) MetricName() string { return c.metricName }
func (c *CounterEvent) Value() float64 { return c.value }
func (c *CounterEvent) Labels() map[string]string { return c.labels }
func (c *CounterEvent) MetricType() mapper.MetricType { return mapper.MetricTypeCounter }
type GaugeEvent struct {
metricName string
value float64
relative bool
labels map[string]string
}
func (g *GaugeEvent) MetricName() string { return g.metricName }
func (g *GaugeEvent) Value() float64 { return g.value }
func (c *GaugeEvent) Labels() map[string]string { return c.labels }
func (c *GaugeEvent) MetricType() mapper.MetricType { return mapper.MetricTypeGauge }
type TimerEvent struct {
metricName string
value float64
labels map[string]string
}
func (t *TimerEvent) MetricName() string { return t.metricName }
func (t *TimerEvent) Value() float64 { return t.value }
func (c *TimerEvent) Labels() map[string]string { return c.labels }
func (c *TimerEvent) MetricType() mapper.MetricType { return mapper.MetricTypeTimer }
type Events []Event
type LabelValues struct {
lastRegisteredAt time.Time
labels prometheus.Labels
ttl time.Duration
}
type Exporter struct {
Counters *CounterContainer
Gauges *GaugeContainer
Summaries *SummaryContainer
Histograms *HistogramContainer
mapper *mapper.MetricMapper
labelValues map[string]map[uint64]*LabelValues
}
func escapeMetricName(metricName string) string {
// If a metric starts with a digit, prepend an underscore.
if len(metricName) > 0 && metricName[0] >= '0' && metricName[0] <= '9' {
metricName = "_" + metricName
}
// Replace all illegal metric chars with underscores.
metricName = illegalCharsRE.ReplaceAllString(metricName, "_")
return metricName
}
// Listen handles all events sent to the given channel sequentially. It
// terminates when the channel is closed.
func (b *Exporter) Listen(e <-chan Events) {
removeStaleMetricsTicker := clock.NewTicker(time.Second)
for {
select {
case <-removeStaleMetricsTicker.C:
b.removeStaleMetrics()
case events, ok := <-e:
if !ok {
log.Debug("Channel is closed. Break out of Exporter.Listener.")
removeStaleMetricsTicker.Stop()
return
}
for _, event := range events {
b.handleEvent(event)
}
}
}
}
// handleEvent processes a single Event according to the configured mapping.
func (b *Exporter) handleEvent(event Event) {
mapping, labels, present := b.mapper.GetMapping(event.MetricName(), event.MetricType())
if mapping == nil {
mapping = &mapper.MetricMapping{}
if b.mapper.Defaults.Ttl != 0 {
mapping.Ttl = b.mapper.Defaults.Ttl
}
}
if mapping.Action == mapper.ActionTypeDrop {
return
}
help := defaultHelp
if mapping.HelpText != "" {
help = mapping.HelpText
}
metricName := ""
prometheusLabels := event.Labels()
if present {
if mapping.Name == "" {
log.Debugf("The mapping of '%s' for match '%s' generates an empty metric name", event.MetricName(), mapping.Match)
errorEventStats.WithLabelValues("empty_metric_name").Inc()
return
}
metricName = escapeMetricName(mapping.Name)
for label, value := range labels {
prometheusLabels[label] = value
}
} else {
eventsUnmapped.Inc()
metricName = escapeMetricName(event.MetricName())
}
switch ev := event.(type) {
case *CounterEvent:
// We don't accept negative values for counters. Incrementing the counter with a negative number
// will cause the exporter to panic. Instead we will warn and continue to the next event.
if event.Value() < 0.0 {
log.Debugf("Counter %q is: '%f' (counter must be non-negative value)", metricName, event.Value())
errorEventStats.WithLabelValues("illegal_negative_counter").Inc()
return
}
counter, err := b.Counters.Get(
metricName,
prometheusLabels,
help,
)
if err == nil {
counter.Add(event.Value())
b.saveLabelValues(metricName, prometheusLabels, mapping.Ttl)
eventStats.WithLabelValues("counter").Inc()
} else {
log.Debugf(regErrF, metricName, err)
conflictingEventStats.WithLabelValues("counter").Inc()
}
case *GaugeEvent:
gauge, err := b.Gauges.Get(
metricName,
prometheusLabels,
help,
)
if err == nil {
if ev.relative {
gauge.Add(event.Value())
} else {
gauge.Set(event.Value())
}
b.saveLabelValues(metricName, prometheusLabels, mapping.Ttl)
eventStats.WithLabelValues("gauge").Inc()
} else {
log.Debugf(regErrF, metricName, err)
conflictingEventStats.WithLabelValues("gauge").Inc()
}
case *TimerEvent:
t := mapper.TimerTypeDefault
if mapping != nil {
t = mapping.TimerType
}
if t == mapper.TimerTypeDefault {
t = b.mapper.Defaults.TimerType
}
switch t {
case mapper.TimerTypeHistogram:
histogram, err := b.Histograms.Get(
metricName,
prometheusLabels,
help,
mapping,
)
if err == nil {
histogram.Observe(event.Value() / 1000) // prometheus presumes seconds, statsd millisecond
b.saveLabelValues(metricName, prometheusLabels, mapping.Ttl)
eventStats.WithLabelValues("timer").Inc()
} else {
log.Debugf(regErrF, metricName, err)
conflictingEventStats.WithLabelValues("timer").Inc()
}
case mapper.TimerTypeDefault, mapper.TimerTypeSummary:
summary, err := b.Summaries.Get(
metricName,
prometheusLabels,
help,
mapping,
)
if err == nil {
summary.Observe(event.Value() / 1000) // prometheus presumes seconds, statsd millisecond
b.saveLabelValues(metricName, prometheusLabels, mapping.Ttl)
eventStats.WithLabelValues("timer").Inc()
} else {
log.Debugf(regErrF, metricName, err)
conflictingEventStats.WithLabelValues("timer").Inc()
}
default:
panic(fmt.Sprintf("unknown timer type '%s'", t))
}
default:
log.Debugln("Unsupported event type")
eventStats.WithLabelValues("illegal").Inc()
}
}
// removeStaleMetrics removes label values set from metric with stale values
func (b *Exporter) removeStaleMetrics() {
now := clock.Now()
// delete timeseries with expired ttl
for metricName := range b.labelValues {
for hash, lvs := range b.labelValues[metricName] {
if lvs.ttl == 0 {
continue
}
if lvs.lastRegisteredAt.Add(lvs.ttl).Before(now) {
b.Counters.Delete(metricName, lvs.labels)
b.Gauges.Delete(metricName, lvs.labels)
b.Summaries.Delete(metricName, lvs.labels)
b.Histograms.Delete(metricName, lvs.labels)
delete(b.labelValues[metricName], hash)
}
}
}
}
// saveLabelValues stores label values set to labelValues and update lastRegisteredAt time and ttl value
func (b *Exporter) saveLabelValues(metricName string, labels prometheus.Labels, ttl time.Duration) {
metric, hasMetric := b.labelValues[metricName]
if !hasMetric {
metric = make(map[uint64]*LabelValues)
b.labelValues[metricName] = metric
}
hash := hashNameAndLabels(metricName, labels)
metricLabelValues, ok := metric[hash]
if !ok {
metricLabelValues = &LabelValues{
labels: labels,
ttl: ttl,
}
b.labelValues[metricName][hash] = metricLabelValues
}
now := clock.Now()
metricLabelValues.lastRegisteredAt = now
// Update ttl from mapping
metricLabelValues.ttl = ttl
}
func NewExporter(mapper *mapper.MetricMapper) *Exporter {
return &Exporter{
Counters: NewCounterContainer(),
Gauges: NewGaugeContainer(),
Summaries: NewSummaryContainer(mapper),
Histograms: NewHistogramContainer(mapper),
mapper: mapper,
labelValues: make(map[string]map[uint64]*LabelValues),
}
}
func buildEvent(statType, metric string, value float64, relative bool, labels map[string]string) (Event, error) {
switch statType {
case "c":
return &CounterEvent{
metricName: metric,
value: float64(value),
labels: labels,
}, nil
case "g":
return &GaugeEvent{
metricName: metric,
value: float64(value),
relative: relative,
labels: labels,
}, nil
case "ms", "h":
return &TimerEvent{
metricName: metric,
value: float64(value),
labels: labels,
}, nil
case "s":
return nil, fmt.Errorf("no support for StatsD sets")
default:
return nil, fmt.Errorf("bad stat type %s", statType)
}
}
func parseDogStatsDTagsToLabels(component string) map[string]string {
labels := map[string]string{}
tagsReceived.Inc()
tags := strings.Split(component, ",")
for _, t := range tags {
t = strings.TrimPrefix(t, "#")
kv := strings.SplitN(t, ":", 2)
if len(kv) < 2 || len(kv[1]) == 0 {
tagErrors.Inc()
log.Debugf("Malformed or empty DogStatsD tag %s in component %s", t, component)
continue
}
labels[escapeMetricName(kv[0])] = kv[1]
}
return labels
}
func lineToEvents(line string) Events {
events := Events{}
if line == "" {
return events
}
elements := strings.SplitN(line, ":", 2)
if len(elements) < 2 || len(elements[0]) == 0 || !utf8.ValidString(line) {
sampleErrors.WithLabelValues("malformed_line").Inc()
log.Debugln("Bad line from StatsD:", line)
return events
}
metric := elements[0]
var samples []string
if strings.Contains(elements[1], "|#") {
// using datadog extensions, disable multi-metrics
samples = elements[1:]
} else {
samples = strings.Split(elements[1], ":")
}
samples:
for _, sample := range samples {
samplesReceived.Inc()
components := strings.Split(sample, "|")
samplingFactor := 1.0
if len(components) < 2 || len(components) > 4 {
sampleErrors.WithLabelValues("malformed_component").Inc()
log.Debugln("Bad component on line:", line)
continue
}
valueStr, statType := components[0], components[1]
var relative = false
if strings.Index(valueStr, "+") == 0 || strings.Index(valueStr, "-") == 0 {
relative = true
}
value, err := strconv.ParseFloat(valueStr, 64)
if err != nil {
log.Debugf("Bad value %s on line: %s", valueStr, line)
sampleErrors.WithLabelValues("malformed_value").Inc()
continue
}
multiplyEvents := 1
labels := map[string]string{}
if len(components) >= 3 {
for _, component := range components[2:] {
if len(component) == 0 {
log.Debugln("Empty component on line: ", line)
sampleErrors.WithLabelValues("malformed_component").Inc()
continue samples
}
}
for _, component := range components[2:] {
switch component[0] {
case '@':
if statType != "c" && statType != "ms" {
log.Debugln("Illegal sampling factor for non-counter metric on line", line)
sampleErrors.WithLabelValues("illegal_sample_factor").Inc()
continue
}
samplingFactor, err = strconv.ParseFloat(component[1:], 64)
if err != nil {
log.Debugf("Invalid sampling factor %s on line %s", component[1:], line)
sampleErrors.WithLabelValues("invalid_sample_factor").Inc()
}
if samplingFactor == 0 {
samplingFactor = 1
}
if statType == "c" {
value /= samplingFactor
} else if statType == "ms" {
multiplyEvents = int(1 / samplingFactor)
}
case '#':
labels = parseDogStatsDTagsToLabels(component)
default:
log.Debugf("Invalid sampling factor or tag section %s on line %s", components[2], line)
sampleErrors.WithLabelValues("invalid_sample_factor").Inc()
continue
}
}
}
for i := 0; i < multiplyEvents; i++ {
event, err := buildEvent(statType, metric, value, relative, labels)
if err != nil {
log.Debugf("Error building event on line %s: %s", line, err)
sampleErrors.WithLabelValues("illegal_event").Inc()
continue
}
events = append(events, event)
}
}
return events
}
type StatsDUDPListener struct {
conn *net.UDPConn
}
func (l *StatsDUDPListener) Listen(e chan<- Events) {
buf := make([]byte, 65535)
for {
n, _, err := l.conn.ReadFromUDP(buf)
if err != nil {
log.Fatal(err)
}
l.handlePacket(buf[0:n], e)
}
}
func (l *StatsDUDPListener) handlePacket(packet []byte, e chan<- Events) {
udpPackets.Inc()
lines := strings.Split(string(packet), "\n")
events := Events{}
for _, line := range lines {
linesReceived.Inc()
events = append(events, lineToEvents(line)...)
}
e <- events
}
type StatsDTCPListener struct {
conn *net.TCPListener
}
func (l *StatsDTCPListener) Listen(e chan<- Events) {
for {
c, err := l.conn.AcceptTCP()
if err != nil {
log.Fatalf("AcceptTCP failed: %v", err)
}
go l.handleConn(c, e)
}
}
func (l *StatsDTCPListener) handleConn(c *net.TCPConn, e chan<- Events) {
defer c.Close()
tcpConnections.Inc()
r := bufio.NewReader(c)
for {
line, isPrefix, err := r.ReadLine()
if err != nil {
if err != io.EOF {
tcpErrors.Inc()
log.Debugf("Read %s failed: %v", c.RemoteAddr(), err)
}
break
}
if isPrefix {
tcpLineTooLong.Inc()
log.Debugf("Read %s failed: line too long", c.RemoteAddr())
break
}
linesReceived.Inc()
e <- lineToEvents(string(line))
}
}
type StatsDUnixgramListener struct {
conn *net.UnixConn
}
func (l *StatsDUnixgramListener) Listen(e chan<- Events) {
buf := make([]byte, 65535)
for {
n, _, err := l.conn.ReadFromUnix(buf)
if err != nil {
log.Fatal(err)
}
l.handlePacket(buf[:n], e)
}
}
func (l *StatsDUnixgramListener) handlePacket(packet []byte, e chan<- Events) {
unixgramPackets.Inc()
lines := strings.Split(string(packet), "\n")
events := Events{}
for _, line := range lines {
linesReceived.Inc()
events = append(events, lineToEvents(line)...)
}
e <- events
}