Node_Exporter/collector/bonding_linux.go
Sachi King 18fc512fc4 Bond: Monitor bond mii_status not link operstate (#1124)
With a bond interface the state of the slave interface from the bond's
point of view is reflected in `mii_status` and is independent of the
link's `operstate`.

When a bond is monitored with `miimon`, `mii_status` will reflect the
state of the physical link as configured via the operator.

When a bond is monitored via `arp_interval` the `mii_status` will
reflect the results of the bond ARP checking.  This means the link can
be down from the bond's point of view, but up from a physical
connection point of view.

If a bond is not monitored via miimon or arp, the `mii_status` should
likely be always `up`, however I have observed a case where this is not
true and the `operstate` is `up` while `mii_status` is `down`.  Kernel
bond documentation stresses that a bond should not be configured without
one of `mii_mon` or `arp_interval` configured however.

This change results in the metric 'node_bonding_active' matching the
up/down state of the bond's point of view rather than operstate.

Signed-off-by: Sachi King <nakato@nakato.io>
2019-02-10 11:00:04 +01:00

102 lines
3.1 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 !nobonding
package collector
import (
"fmt"
"io/ioutil"
"os"
"path/filepath"
"strings"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/log"
)
type bondingCollector struct {
slaves, active typedDesc
}
func init() {
registerCollector("bonding", defaultEnabled, NewBondingCollector)
}
// NewBondingCollector returns a newly allocated bondingCollector.
// It exposes the number of configured and active slave of linux bonding interfaces.
func NewBondingCollector() (Collector, error) {
return &bondingCollector{
slaves: typedDesc{prometheus.NewDesc(
prometheus.BuildFQName(namespace, "bonding", "slaves"),
"Number of configured slaves per bonding interface.",
[]string{"master"}, nil,
), prometheus.GaugeValue},
active: typedDesc{prometheus.NewDesc(
prometheus.BuildFQName(namespace, "bonding", "active"),
"Number of active slaves per bonding interface.",
[]string{"master"}, nil,
), prometheus.GaugeValue},
}, nil
}
// Update reads and exposes bonding states, implements Collector interface. Caution: This works only on linux.
func (c *bondingCollector) Update(ch chan<- prometheus.Metric) error {
statusfile := sysFilePath("class/net")
bondingStats, err := readBondingStats(statusfile)
if err != nil {
if os.IsNotExist(err) {
log.Debugf("Not collecting bonding, file does not exist: %s", statusfile)
return nil
}
return err
}
for master, status := range bondingStats {
ch <- c.slaves.mustNewConstMetric(float64(status[0]), master)
ch <- c.active.mustNewConstMetric(float64(status[1]), master)
}
return nil
}
func readBondingStats(root string) (status map[string][2]int, err error) {
status = map[string][2]int{}
masters, err := ioutil.ReadFile(filepath.Join(root, "bonding_masters"))
if err != nil {
return nil, err
}
for _, master := range strings.Fields(string(masters)) {
slaves, err := ioutil.ReadFile(filepath.Join(root, master, "bonding", "slaves"))
if err != nil {
return nil, err
}
sstat := [2]int{0, 0}
for _, slave := range strings.Fields(string(slaves)) {
state, err := ioutil.ReadFile(filepath.Join(root, master, fmt.Sprintf("lower_%s", slave), "bonding_slave", "mii_status"))
if os.IsNotExist(err) {
// some older? kernels use slave_ prefix
state, err = ioutil.ReadFile(filepath.Join(root, master, fmt.Sprintf("slave_%s", slave), "bonding_slave", "mii_status"))
}
if err != nil {
return nil, err
}
sstat[0]++
if strings.TrimSpace(string(state)) == "up" {
sstat[1]++
}
}
status[master] = sstat
}
return status, err
}