telegraf/plugins/statsd/statsd.go

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package statsd
import (
"errors"
"fmt"
"log"
"net"
"sort"
"strconv"
"strings"
"sync"
"github.com/influxdb/influxdb/services/graphite"
"github.com/influxdb/telegraf/plugins"
)
var dropwarn = "ERROR: Message queue full. Discarding line [%s] " +
"You may want to increase allowed_pending_messages in the config\n"
type Statsd struct {
// Address & Port to serve from
ServiceAddress string
// Number of messages allowed to queue up in between calls to Gather. If this
// fills up, packets will get dropped until the next Gather interval is ran.
AllowedPendingMessages int
// Percentiles specifies the percentiles that will be calculated for timing
// and histogram stats.
Percentiles []int
PercentileLimit int
DeleteGauges bool
DeleteCounters bool
DeleteSets bool
DeleteTimings bool
sync.Mutex
// Channel for all incoming statsd messages
in chan string
done chan struct{}
// Cache gauges, counters & sets so they can be aggregated as they arrive
gauges map[string]cachedgauge
counters map[string]cachedcounter
sets map[string]cachedset
timings map[string]cachedtimings
// bucket -> influx templates
Templates []string
}
func NewStatsd() *Statsd {
s := Statsd{}
// Make data structures
s.done = make(chan struct{})
s.in = make(chan string, s.AllowedPendingMessages)
s.gauges = make(map[string]cachedgauge)
s.counters = make(map[string]cachedcounter)
s.sets = make(map[string]cachedset)
s.timings = make(map[string]cachedtimings)
return &s
}
// One statsd metric, form is <bucket>:<value>|<mtype>|@<samplerate>
type metric struct {
name string
bucket string
hash string
intvalue int64
floatvalue float64
mtype string
additive bool
samplerate float64
tags map[string]string
}
type cachedset struct {
name string
set map[int64]bool
tags map[string]string
}
type cachedgauge struct {
name string
value float64
tags map[string]string
}
type cachedcounter struct {
name string
value int64
tags map[string]string
}
type cachedtimings struct {
name string
stats RunningStats
tags map[string]string
}
func (_ *Statsd) Description() string {
return "Statsd Server"
}
const sampleConfig = `
# Address and port to host UDP listener on
service_address = ":8125"
# Delete gauges every interval (default=false)
delete_gauges = false
# Delete counters every interval (default=false)
delete_counters = false
# Delete sets every interval (default=false)
delete_sets = false
# Delete timings & histograms every interval (default=true)
delete_timings = true
# Percentiles to calculate for timing & histogram stats
percentiles = [90]
# templates = [
# "cpu.* measurement*"
# ]
# Number of UDP messages allowed to queue up, once filled,
# the statsd server will start dropping packets
allowed_pending_messages = 10000
# Number of timing/histogram values to track per-measurement in the
# calculation of percentiles. Raising this limit increases the accuracy
# of percentiles but also increases the memory usage and cpu time.
percentile_limit = 1000
`
func (_ *Statsd) SampleConfig() string {
return sampleConfig
}
func (s *Statsd) Gather(acc plugins.Accumulator) error {
s.Lock()
defer s.Unlock()
for _, metric := range s.timings {
acc.Add(metric.name+"_mean", metric.stats.Mean(), metric.tags)
acc.Add(metric.name+"_stddev", metric.stats.Stddev(), metric.tags)
acc.Add(metric.name+"_upper", metric.stats.Upper(), metric.tags)
acc.Add(metric.name+"_lower", metric.stats.Lower(), metric.tags)
acc.Add(metric.name+"_count", metric.stats.Count(), metric.tags)
for _, percentile := range s.Percentiles {
name := fmt.Sprintf("%s_percentile_%v", metric.name, percentile)
acc.Add(name, metric.stats.Percentile(percentile), metric.tags)
}
}
if s.DeleteTimings {
s.timings = make(map[string]cachedtimings)
}
for _, metric := range s.gauges {
acc.Add(metric.name, metric.value, metric.tags)
}
if s.DeleteGauges {
s.gauges = make(map[string]cachedgauge)
}
for _, metric := range s.counters {
acc.Add(metric.name, metric.value, metric.tags)
}
if s.DeleteCounters {
s.counters = make(map[string]cachedcounter)
}
for _, metric := range s.sets {
acc.Add(metric.name, int64(len(metric.set)), metric.tags)
}
if s.DeleteSets {
s.sets = make(map[string]cachedset)
}
return nil
}
func (s *Statsd) Start() error {
log.Println("Starting up the statsd service")
// Make data structures
s.done = make(chan struct{})
s.in = make(chan string, s.AllowedPendingMessages)
s.gauges = make(map[string]cachedgauge)
s.counters = make(map[string]cachedcounter)
s.sets = make(map[string]cachedset)
s.timings = make(map[string]cachedtimings)
// Start the UDP listener
go s.udpListen()
// Start the line parser
go s.parser()
return nil
}
// udpListen starts listening for udp packets on the configured port.
func (s *Statsd) udpListen() error {
address, _ := net.ResolveUDPAddr("udp", s.ServiceAddress)
listener, err := net.ListenUDP("udp", address)
if err != nil {
log.Fatalf("ERROR: ListenUDP - %s", err)
}
defer listener.Close()
log.Println("Statsd listener listening on: ", listener.LocalAddr().String())
for {
select {
case <-s.done:
return nil
default:
buf := make([]byte, 1024)
n, _, err := listener.ReadFromUDP(buf)
if err != nil {
log.Printf("ERROR: %s\n", err.Error())
}
lines := strings.Split(string(buf[:n]), "\n")
for _, line := range lines {
line = strings.TrimSpace(line)
if line != "" {
select {
case s.in <- line:
default:
log.Printf(dropwarn, line)
}
}
}
}
}
}
// parser monitors the s.in channel, if there is a line ready, it parses the
// statsd string into a usable metric struct and aggregates the value
func (s *Statsd) parser() error {
for {
select {
case <-s.done:
return nil
case line := <-s.in:
s.parseStatsdLine(line)
}
}
}
// parseStatsdLine will parse the given statsd line, validating it as it goes.
// If the line is valid, it will be cached for the next call to Gather()
func (s *Statsd) parseStatsdLine(line string) error {
s.Lock()
defer s.Unlock()
m := metric{}
// Validate splitting the line on "|"
pipesplit := strings.Split(line, "|")
if len(pipesplit) < 2 {
log.Printf("Error: splitting '|', Unable to parse metric: %s\n", line)
return errors.New("Error Parsing statsd line")
} else if len(pipesplit) > 2 {
sr := pipesplit[2]
errmsg := "Error: parsing sample rate, %s, it must be in format like: " +
"@0.1, @0.5, etc. Ignoring sample rate for line: %s\n"
if strings.Contains(sr, "@") && len(sr) > 1 {
samplerate, err := strconv.ParseFloat(sr[1:], 64)
if err != nil {
log.Printf(errmsg, err.Error(), line)
} else {
// sample rate successfully parsed
m.samplerate = samplerate
}
} else {
log.Printf(errmsg, "", line)
}
}
// Validate metric type
switch pipesplit[1] {
case "g", "c", "s", "ms", "h":
m.mtype = pipesplit[1]
default:
log.Printf("Error: Statsd Metric type %s unsupported", pipesplit[1])
return errors.New("Error Parsing statsd line")
}
// Validate splitting the rest of the line on ":"
colonsplit := strings.Split(pipesplit[0], ":")
if len(colonsplit) != 2 {
log.Printf("Error: splitting ':', Unable to parse metric: %s\n", line)
return errors.New("Error Parsing statsd line")
}
m.bucket = colonsplit[0]
// Parse the value
if strings.ContainsAny(colonsplit[1], "-+") {
if m.mtype != "g" {
log.Printf("Error: +- values are only supported for gauges: %s\n", line)
return errors.New("Error Parsing statsd line")
}
m.additive = true
}
switch m.mtype {
case "g", "ms", "h":
v, err := strconv.ParseFloat(colonsplit[1], 64)
if err != nil {
log.Printf("Error: parsing value to float64: %s\n", line)
return errors.New("Error Parsing statsd line")
}
m.floatvalue = v
case "c", "s":
v, err := strconv.ParseInt(colonsplit[1], 10, 64)
if err != nil {
log.Printf("Error: parsing value to int64: %s\n", line)
return errors.New("Error Parsing statsd line")
}
// If a sample rate is given with a counter, divide value by the rate
if m.samplerate != 0 && m.mtype == "c" {
v = int64(float64(v) / m.samplerate)
}
m.intvalue = v
}
// Parse the name & tags from bucket
m.name, m.tags = s.parseName(m.bucket)
switch m.mtype {
case "c":
m.tags["metric_type"] = "counter"
case "g":
m.tags["metric_type"] = "gauge"
case "s":
m.tags["metric_type"] = "set"
case "ms":
m.tags["metric_type"] = "timing"
case "h":
m.tags["metric_type"] = "histogram"
}
// Make a unique key for the measurement name/tags
var tg []string
for k, v := range m.tags {
tg = append(tg, fmt.Sprintf("%s=%s", k, v))
}
sort.Strings(tg)
m.hash = fmt.Sprintf("%s%s", strings.Join(tg, ""), m.name)
s.aggregate(m)
return nil
}
// parseName parses the given bucket name with the list of bucket maps in the
// config file. If there is a match, it will parse the name of the metric and
// map of tags.
// Return values are (<name>, <tags>)
func (s *Statsd) parseName(bucket string) (string, map[string]string) {
tags := make(map[string]string)
bucketparts := strings.Split(bucket, ",")
// Parse out any tags in the bucket
if len(bucketparts) > 1 {
for _, btag := range bucketparts[1:] {
k, v := parseKeyValue(btag)
if k != "" {
tags[k] = v
}
}
}
o := graphite.Options{
Separator: "_",
Templates: s.Templates,
DefaultTags: tags,
}
name := bucketparts[0]
p, err := graphite.NewParserWithOptions(o)
if err == nil {
name, tags, _, _ = p.ApplyTemplate(name)
}
name = strings.Replace(name, ".", "_", -1)
name = strings.Replace(name, "-", "__", -1)
return name, tags
}
// Parse the key,value out of a string that looks like "key=value"
func parseKeyValue(keyvalue string) (string, string) {
var key, val string
split := strings.Split(keyvalue, "=")
// Must be exactly 2 to get anything meaningful out of them
if len(split) == 2 {
key = split[0]
val = split[1]
} else if len(split) == 1 {
val = split[0]
}
return key, val
}
// aggregate takes in a metric. It then
// aggregates and caches the current value(s). It does not deal with the
// Delete* options, because those are dealt with in the Gather function.
func (s *Statsd) aggregate(m metric) {
switch m.mtype {
case "ms", "h":
cached, ok := s.timings[m.hash]
if !ok {
cached = cachedtimings{
name: m.name,
tags: m.tags,
stats: RunningStats{
PercLimit: s.PercentileLimit,
},
}
}
if m.samplerate > 0 {
for i := 0; i < int(1.0/m.samplerate); i++ {
cached.stats.AddValue(m.floatvalue)
}
s.timings[m.hash] = cached
} else {
cached.stats.AddValue(m.floatvalue)
s.timings[m.hash] = cached
}
case "c":
cached, ok := s.counters[m.hash]
if !ok {
s.counters[m.hash] = cachedcounter{
name: m.name,
value: m.intvalue,
tags: m.tags,
}
} else {
cached.value += m.intvalue
s.counters[m.hash] = cached
}
case "g":
cached, ok := s.gauges[m.hash]
if !ok {
s.gauges[m.hash] = cachedgauge{
name: m.name,
value: m.floatvalue,
tags: m.tags,
}
} else {
if m.additive {
cached.value = cached.value + m.floatvalue
} else {
cached.value = m.floatvalue
}
s.gauges[m.hash] = cached
}
case "s":
cached, ok := s.sets[m.hash]
if !ok {
// Completely new metric (initialize with count of 1)
s.sets[m.hash] = cachedset{
name: m.name,
tags: m.tags,
set: map[int64]bool{m.intvalue: true},
}
} else {
cached.set[m.intvalue] = true
s.sets[m.hash] = cached
}
}
}
func (s *Statsd) Stop() {
s.Lock()
defer s.Unlock()
log.Println("Stopping the statsd service")
close(s.done)
close(s.in)
}
func init() {
plugins.Add("statsd", func() plugins.Plugin {
return &Statsd{}
})
}