node_exporter/collector/diskstats_linux.go

244 lines
6.9 KiB
Go

// Copyright 2015 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 !nodiskstats
package collector
import (
"bufio"
"flag"
"fmt"
"io"
"os"
"regexp"
"strconv"
"strings"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/log"
)
const (
diskSubsystem = "disk"
diskSectorSize uint64 = 512
)
var (
ignoredDevices = flag.String("collector.diskstats.ignored-devices", "^(ram|loop|fd|(h|s|v|xv)d[a-z]|nvme\\d+n\\d+p)\\d+$", "Regexp of devices to ignore for diskstats.")
)
type diskstatsCollector struct {
ignoredDevicesPattern *regexp.Regexp
descs []typedDesc
}
func init() {
Factories["diskstats"] = NewDiskstatsCollector
}
// NewDiskstatsCollector returns a new Collector exposing disk device stats.
func NewDiskstatsCollector() (Collector, error) {
var diskLabelNames = []string{"device"}
return &diskstatsCollector{
ignoredDevicesPattern: regexp.MustCompile(*ignoredDevices),
// Docs from https://www.kernel.org/doc/Documentation/iostats.txt
descs: []typedDesc{
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "reads_completed"),
"The total number of reads completed successfully.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "reads_merged"),
"The total number of reads merged. See https://www.kernel.org/doc/Documentation/iostats.txt.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "sectors_read"),
"The total number of sectors read successfully.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "read_time_ms"),
"The total number of milliseconds spent by all reads.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "writes_completed"),
"The total number of writes completed successfully.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "writes_merged"),
"The number of writes merged. See https://www.kernel.org/doc/Documentation/iostats.txt.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "sectors_written"),
"The total number of sectors written successfully.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "write_time_ms"),
"This is the total number of milliseconds spent by all writes.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "io_now"),
"The number of I/Os currently in progress.",
diskLabelNames,
nil,
), valueType: prometheus.GaugeValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "io_time_ms"),
"Total Milliseconds spent doing I/Os.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "io_time_weighted"),
"The weighted # of milliseconds spent doing I/Os. See https://www.kernel.org/doc/Documentation/iostats.txt.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "bytes_read"),
"The total number of bytes read successfully.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
{
desc: prometheus.NewDesc(
prometheus.BuildFQName(Namespace, diskSubsystem, "bytes_written"),
"The total number of bytes written successfully.",
diskLabelNames,
nil,
), valueType: prometheus.CounterValue,
},
},
}, nil
}
func (c *diskstatsCollector) Update(ch chan<- prometheus.Metric) error {
procDiskStats := procFilePath("diskstats")
diskStats, err := getDiskStats()
if err != nil {
return fmt.Errorf("couldn't get diskstats: %s", err)
}
for dev, stats := range diskStats {
if c.ignoredDevicesPattern.MatchString(dev) {
log.Debugf("Ignoring device: %s", dev)
continue
}
if len(stats) != len(c.descs) {
return fmt.Errorf("invalid line for %s for %s", procDiskStats, dev)
}
for i, value := range stats {
v, err := strconv.ParseFloat(value, 64)
if err != nil {
return fmt.Errorf("invalid value %s in diskstats: %s", value, err)
}
ch <- c.descs[i].mustNewConstMetric(v, dev)
}
}
return nil
}
func getDiskStats() (map[string]map[int]string, error) {
file, err := os.Open(procFilePath("diskstats"))
if err != nil {
return nil, err
}
defer file.Close()
return parseDiskStats(file)
}
func convertDiskSectorsToBytes(sectorCount string) (string, error) {
sectors, err := strconv.ParseUint(sectorCount, 10, 64)
if err != nil {
return "", err
}
return strconv.FormatUint(sectors*diskSectorSize, 10), nil
}
func parseDiskStats(r io.Reader) (map[string]map[int]string, error) {
var (
diskStats = map[string]map[int]string{}
scanner = bufio.NewScanner(r)
)
for scanner.Scan() {
parts := strings.Fields(scanner.Text())
if len(parts) < 4 { // we strip major, minor and dev
return nil, fmt.Errorf("invalid line in %s: %s", procFilePath("diskstats"), scanner.Text())
}
dev := parts[2]
diskStats[dev] = map[int]string{}
for i, v := range parts[3:] {
diskStats[dev][i] = v
}
bytesRead, err := convertDiskSectorsToBytes(diskStats[dev][2])
if err != nil {
return nil, fmt.Errorf("invalid value for sectors read in %s: %s", procFilePath("diskstats"), scanner.Text())
}
diskStats[dev][11] = bytesRead
bytesWritten, err := convertDiskSectorsToBytes(diskStats[dev][6])
if err != nil {
return nil, fmt.Errorf("invalid value for sectors written in %s: %s", procFilePath("diskstats"), scanner.Text())
}
diskStats[dev][12] = bytesWritten
}
return diskStats, scanner.Err()
}