Node_Exporter/collector/vmstat_linux.go
Brian Brazil 499c342fed Greatly reduce the metrics vmstat returns by default.
Vmstat has over 100 fields, most of which are highly
detailed debug information. Trim this down to only
essential fields by default, configurable by flag.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>
2018-03-29 22:00:02 +01:00

83 lines
2.0 KiB
Go

// Copyright 2016 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.
// +build !novmstat
package collector
import (
"bufio"
"fmt"
"os"
"regexp"
"strconv"
"strings"
"github.com/prometheus/client_golang/prometheus"
"gopkg.in/alecthomas/kingpin.v2"
)
const (
vmStatSubsystem = "vmstat"
)
var (
vmStatFields = kingpin.Flag("collector.vmstat.fields", "Regexp of fields to return for vmstat collector.").Default("^(pgpg|pswp|pg.*fault|oom_kill).*").String()
)
type vmStatCollector struct {
fieldPattern *regexp.Regexp
}
func init() {
registerCollector("vmstat", defaultEnabled, NewvmStatCollector)
}
// NewvmStatCollector returns a new Collector exposing vmstat stats.
func NewvmStatCollector() (Collector, error) {
pattern := regexp.MustCompile(*vmStatFields)
return &vmStatCollector{
fieldPattern: pattern,
}, nil
}
func (c *vmStatCollector) Update(ch chan<- prometheus.Metric) error {
file, err := os.Open(procFilePath("vmstat"))
if err != nil {
return err
}
defer file.Close()
scanner := bufio.NewScanner(file)
for scanner.Scan() {
parts := strings.Fields(scanner.Text())
value, err := strconv.ParseFloat(parts[1], 64)
if err != nil {
return err
}
if !c.fieldPattern.MatchString(parts[0]) {
continue
}
ch <- prometheus.MustNewConstMetric(
prometheus.NewDesc(
prometheus.BuildFQName(namespace, vmStatSubsystem, parts[0]),
fmt.Sprintf("/proc/vmstat information field %s.", parts[0]),
nil, nil),
prometheus.UntypedValue,
value,
)
}
return scanner.Err()
}