node_exporter/collector/gmond_collector.go
Brian Brazil 1c17481a42 Collect at every scrape, rather than at regular intervals.
Switch to Update using the Collecter Collect interface, due to not knowing all
metricnames in all modules beforehand we can't use Describe and thus the full
Collecter interface.

Remove 'updates', it's meaning varies by module and doesn't add much.
2014-10-29 17:00:36 +00:00

112 lines
2.5 KiB
Go

// +build ganglia
package collector
import (
"bufio"
"encoding/xml"
"fmt"
"io"
"net"
"regexp"
"time"
"github.com/golang/glog"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/node_exporter/collector/ganglia"
)
const (
gangliaAddress = "127.0.0.1:8649"
gangliaProto = "tcp"
gangliaTimeout = 30 * time.Second
gangliaMetricsPrefix = "ganglia_"
)
type gmondCollector struct {
Metrics map[string]*prometheus.GaugeVec
config Config
}
func init() {
Factories["gmond"] = NewGmondCollector
}
var illegalCharsRE = regexp.MustCompile(`[^a-zA-Z0-9_]`)
// Takes a config struct and prometheus registry and returns a new Collector scraping ganglia.
func NewGmondCollector(config Config) (Collector, error) {
c := gmondCollector{
config: config,
Metrics: map[string]*prometheus.GaugeVec{},
}
return &c, nil
}
func (c *gmondCollector) setMetric(name, cluster string, metric ganglia.Metric) {
if _, ok := c.Metrics[name]; !ok {
var desc string
var title string
for _, element := range metric.ExtraData.ExtraElements {
switch element.Name {
case "DESC":
desc = element.Val
case "TITLE":
title = element.Val
}
if title != "" && desc != "" {
break
}
}
glog.V(1).Infof("Register %s: %s", name, desc)
gv := prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: gangliaMetricsPrefix,
Name: name,
Help: desc,
},
[]string{"cluster"},
)
}
glog.V(1).Infof("Set %s{cluster=%q}: %f", name, cluster, metric.Value)
c.Metrics[name].WithLabelValues(cluster).Set(metric.Value)
}
func (c *gmondCollector) Update(ch chan<- prometheus.Metric) (err error) {
conn, err := net.Dial(gangliaProto, gangliaAddress)
glog.V(1).Infof("gmondCollector Update")
if err != nil {
return fmt.Errorf("Can't connect to gmond: %s", err)
}
conn.SetDeadline(time.Now().Add(gangliaTimeout))
ganglia := ganglia.Ganglia{}
decoder := xml.NewDecoder(bufio.NewReader(conn))
decoder.CharsetReader = toUtf8
err = decoder.Decode(&ganglia)
if err != nil {
return fmt.Errorf("Couldn't parse xml: %s", err)
}
for _, cluster := range ganglia.Clusters {
for _, host := range cluster.Hosts {
for _, metric := range host.Metrics {
name := illegalCharsRE.ReplaceAllString(metric.Name, "_")
c.setMetric(name, cluster.Name, metric)
}
}
}
for _, m := range c.Metrics {
m.Collect(ch)
}
return err
}
func toUtf8(charset string, input io.Reader) (io.Reader, error) {
return input, nil //FIXME
}