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Fix and simplify parsing of raid metrics

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Fixes the wrong reporting of active+total disk metrics for inactive
raids. Also simplifies the code and removes a couple of redundant
comments.
This commit is contained in:
Tobias Schmidt 2017-03-18 14:36:26 -03:00
commit 0400e437be
3 changed files with 51 additions and 85 deletions
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132
collector/mdadm_linux.go
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@ -36,8 +36,8 @@ var (
)
type mdStatus struct {
mdName string
isActive bool
name string
active bool
disksActive int64
disksTotal int64
blocksTotal int64
@ -136,97 +136,78 @@ func parseMdstat(mdStatusFilePath string) ([]mdStatus, error) {
return []mdStatus{}, fmt.Errorf("error parsing mdstat: %s", err)
}
mdStatusFile := string(content)
lines := strings.Split(mdStatusFile, "\n")
var (
currentMD string
personality string
active, total, size int64
)
lines := strings.Split(string(content), "\n")
// Each md has at least the deviceline, statusline and one empty line afterwards
// so we will have probably something of the order len(lines)/3 devices
// so we use that for preallocation.
estimateMDs := len(lines) / 3
mdStates := make([]mdStatus, 0, estimateMDs)
for i, l := range lines {
if l == "" {
// Skip entirely empty lines.
mdStates := make([]mdStatus, 0, len(lines)/3)
for i, line := range lines {
if line == "" {
continue
}
if line[0] == ' ' || line[0] == '\t' {
// Lines starting with white space are not the beginning of a md-section.
continue
}
if strings.HasPrefix(line, "Personalities") || strings.HasPrefix(line, "unused") {
// These lines contain general information.
continue
}
if l[0] == ' ' || l[0] == '\t' {
// Those lines are not the beginning of a md-section.
continue
}
if strings.HasPrefix(l, "Personalities") || strings.HasPrefix(l, "unused") {
// We aren't interested in lines with general info.
continue
}
mainLine := strings.Split(l, " ")
mainLine := strings.Split(line, " ")
if len(mainLine) < 4 {
return mdStates, fmt.Errorf("error parsing mdline: %s", l)
return mdStates, fmt.Errorf("error parsing mdline: %s", line)
}
currentMD = mainLine[0] // The name of the md-device.
isActive := (mainLine[2] == "active") // The activity status of the md-device.
personality = ""
md := mdStatus{
name: mainLine[0],
active: mainLine[2] == "active",
}
if len(lines) <= i+3 {
return mdStates, fmt.Errorf("error parsing mdstat: entry for %s has fewer lines than expected", md.name)
}
personality := ""
for _, possiblePersonality := range mainLine[3:] {
if raidPersonalityRE.MatchString(possiblePersonality) {
personality = possiblePersonality
break
}
}
if len(lines) <= i+3 {
return mdStates, fmt.Errorf("error parsing mdstat: entry for %s has fewer lines than expected", currentMD)
}
switch {
case personality == "raid0":
active = int64(len(mainLine) - 4) // Get the number of devices from the main line.
total = active // Raid0 active and total is always the same if active.
size, err = evalRaid0line(lines[i+1]) // Parse statusline, always present.
md.disksActive = int64(len(mainLine) - 4) // Get the number of devices from the main line.
md.disksTotal = md.disksActive // Raid0 active and total is always the same if active.
md.blocksTotal, err = evalRaid0line(lines[i+1])
case raidPersonalityRE.MatchString(personality):
active, total, size, err = evalStatusline(lines[i+1]) // Parse statusline, always present.
md.disksActive, md.disksTotal, md.blocksTotal, err = evalStatusline(lines[i+1])
default:
log.Infof("Personality unknown: %s\n", mainLine)
size, err = evalUnknownPersonalitylineRE(lines[i+1]) // Parse statusline, always present.
md.blocksTotal, err = evalUnknownPersonalitylineRE(lines[i+1])
}
if err != nil {
return mdStates, fmt.Errorf("error parsing mdstat: %s", err)
}
// Now get the number of synced blocks.
var syncedBlocks int64
// Get the line number of the syncing-line.
var j int
if strings.Contains(lines[i+2], "bitmap") { // then skip the bitmap line
j = i + 3
} else {
j = i + 2
syncLine := lines[i+2]
if strings.Contains(syncLine, "bitmap") {
syncLine = lines[i+3]
}
// If device is syncing at the moment, get the number of currently synced bytes,
// otherwise that number equals the size of the device.
if strings.Contains(lines[j], "recovery") ||
strings.Contains(lines[j], "resync") &&
!strings.Contains(lines[j], "\tresync=") {
syncedBlocks, err = evalBuildline(lines[j])
if strings.Contains(syncLine, "recovery") ||
strings.Contains(syncLine, "resync") &&
!strings.Contains(syncLine, "\tresync=") {
md.blocksSynced, err = evalBuildline(syncLine)
if err != nil {
return mdStates, fmt.Errorf("error parsing mdstat: %s", err)
}
} else {
syncedBlocks = size
md.blocksSynced = md.blocksTotal
}
mdStates = append(mdStates, mdStatus{currentMD, isActive, active, total, size, syncedBlocks})
mdStates = append(mdStates, md)
}
return mdStates, nil
@ -277,68 +258,55 @@ var (
func (c *mdadmCollector) Update(ch chan<- prometheus.Metric) error {
statusfile := procFilePath("mdstat")
if _, err := os.Stat(statusfile); err != nil {
// Take care we don't crash on non-existent statusfiles.
if os.IsNotExist(err) {
// no such file or directory, nothing to do, just return
log.Debugf("Not collecting mdstat, file does not exist: %s", statusfile)
return nil
}
return err
}
// First parse mdstat-file...
mdstate, err := parseMdstat(statusfile)
if err != nil {
return fmt.Errorf("error parsing mdstatus: %s", err)
}
// ... and then plug the result into the metrics to be exported.
var isActiveFloat float64
for _, mds := range mdstate {
log.Debugf("collecting metrics for device %s", mds.name)
log.Debugf("collecting metrics for device %s", mds.mdName)
if mds.isActive {
isActiveFloat = 1
} else {
isActiveFloat = 0
var active float64
if mds.active {
active = 1
}
ch <- prometheus.MustNewConstMetric(
isActiveDesc,
prometheus.GaugeValue,
isActiveFloat,
mds.mdName,
active,
mds.name,
)
ch <- prometheus.MustNewConstMetric(
disksActiveDesc,
prometheus.GaugeValue,
float64(mds.disksActive),
mds.mdName,
mds.name,
)
ch <- prometheus.MustNewConstMetric(
disksTotalDesc,
prometheus.GaugeValue,
float64(mds.disksTotal),
mds.mdName,
mds.name,
)
ch <- prometheus.MustNewConstMetric(
blocksTotalDesc,
prometheus.GaugeValue,
float64(mds.blocksTotal),
mds.mdName,
mds.name,
)
ch <- prometheus.MustNewConstMetric(
blocksSyncedDesc,
prometheus.GaugeValue,
float64(mds.blocksSynced),
mds.mdName,
mds.name,
)
}
return nil