Add IO stats and ext4 FS stats through new ext4 collector

collector/diskstats_linux.go

@@ -85,6 +85,8 @@ type diskstatsCollector struct {
 	filesystemInfoDesc      typedFactorDesc
 	deviceMapperInfoDesc    typedFactorDesc
 	ataDescs                map[string]typedFactorDesc
+	ioErrDesc               typedFactorDesc
+	ioDoneDesc              typedFactorDesc
 	logger                  log.Logger
 	getUdevDeviceProperties func(uint32, uint32) (udevInfo, error)
 }
@@ -257,6 +259,20 @@ func NewDiskstatsCollector(logger log.Logger) (Collector, error) {
 				), valueType: prometheus.GaugeValue,
 			},
 		},
+		ioErrDesc: typedFactorDesc{
+			desc: prometheus.NewDesc(prometheus.BuildFQName(namespace, diskSubsystem, "ioerr_total"),
+			"Number of IO commands that completed with an error.",
+				[]string{"device"},
+				nil,
+			), valueType: prometheus.CounterValue,
+		},
+		ioDoneDesc: typedFactorDesc{
+			desc: prometheus.NewDesc(prometheus.BuildFQName(namespace, diskSubsystem, "iodone_total"),
+			"Number of completed or rejected IO commands.",
+				[]string{"device"},
+				nil,
+			), valueType: prometheus.CounterValue,
+		},
 		logger: logger,
 	}
 
@@ -366,6 +382,13 @@ func (c *diskstatsCollector) Update(ch chan<- prometheus.Metric) error {
 				}
 			}
 		}
+
+		if ioDiskStats, err := c.fs.SysBlockDeviceIOStat(dev); err == nil {
+			ch <- c.ioDoneDesc.mustNewConstMetric(float64(ioDiskStats.IODoneCount), dev)
+			ch <- c.ioErrDesc.mustNewConstMetric(float64(ioDiskStats.IOErrCount), dev)
+		} else {
+			level.Debug(c.logger).Log("msg", "Error reading IO errors count", "err", err)
+		}
 	}
 	return nil
 }

collector/diskstats_linux_test.go

@@ -179,6 +179,14 @@ node_disk_io_time_weighted_seconds_total{device="sdb"} 67.07000000000001
 node_disk_io_time_weighted_seconds_total{device="sdc"} 17.07
 node_disk_io_time_weighted_seconds_total{device="sr0"} 0
 node_disk_io_time_weighted_seconds_total{device="vda"} 2.0778722280000001e+06
+# HELP node_disk_iodone_total Number of completed or rejected IO commands.
+# TYPE node_disk_iodone_total counter
+node_disk_iodone_total{device="sda"} 307
+node_disk_iodone_total{device="sr0"} 2767
+# HELP node_disk_ioerr_total Number of IO commands that completed with an error.
+# TYPE node_disk_ioerr_total counter
+node_disk_ioerr_total{device="sda"} 3
+node_disk_ioerr_total{device="sr0"} 29
 # HELP node_disk_read_bytes_total The total number of bytes read successfully.
 # TYPE node_disk_read_bytes_total counter
 node_disk_read_bytes_total{device="dm-0"} 5.13708655616e+11

collector/ext4_linux.go

@@ -0,0 +1,110 @@
+// Copyright 2017 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.
+
+//go:build !noext4
+// +build !noext4
+
+package collector
+
+import (
+	"fmt"
+
+	"github.com/go-kit/log"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/procfs/ext4"
+)
+
+// An ext4Collector is a Collector which gathers metrics from ext4 filesystems.
+type ext4Collector struct {
+	fs     ext4.FS
+	logger log.Logger
+}
+
+func init() {
+	registerCollector("ext4", defaultEnabled, NewExt4Collector)
+}
+
+// NewExt4Collector returns a new Collector exposing ext4 statistics.
+func NewExt4Collector(logger log.Logger) (Collector, error) {
+	fs, err := ext4.NewFS(*procPath, *sysPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open sysfs: %w", err)
+	}
+
+	return &ext4Collector{
+		fs:     fs,
+		logger: logger,
+	}, nil
+}
+
+// Update implements Collector.
+func (c *ext4Collector) Update(ch chan<- prometheus.Metric) error {
+	stats, err := c.fs.ProcStat()
+	if err != nil {
+		return fmt.Errorf("failed to retrieve ext4 stats: %w", err)
+	}
+
+	for _, s := range stats {
+		c.updateExt4Stats(ch, s)
+	}
+
+	return nil
+}
+
+// updateExt4Stats collects statistics for a single ext4 filesystem.
+func (c *ext4Collector) updateExt4Stats(ch chan<- prometheus.Metric, s *ext4.Stats) {
+	const (
+		subsystem = "ext4"
+	)
+	var (
+		labels = []string{"device"}
+	)
+
+	metrics := []struct {
+		name  string
+		desc  string
+		value float64
+	}{
+		{
+			name:  "errors",
+			desc:  "Number of ext4 filesystem errors.",
+			value: float64(s.Errors),
+		},
+		{
+			name:  "warnings",
+			desc:  "Number of ext4 filesystem warnings.",
+			value: float64(s.Warnings),
+		},
+		{
+			name:  "messages",
+			desc:  "Number of ext4 filesystem log messages.",
+			value: float64(s.Messages),
+		},
+	}
+
+	for _, m := range metrics {
+		desc := prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, subsystem, m.name),
+			m.desc,
+			labels,
+			nil,
+		)
+
+		ch <- prometheus.MustNewConstMetric(
+			desc,
+			prometheus.CounterValue,
+			m.value,
+			s.Name,
+		)
+	}
+}

go.mod

@@ -59,3 +59,5 @@ require (
 	google.golang.org/protobuf v1.33.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )
+
+replace github.com/prometheus/procfs => /home/shb/work/oss/procfs