// Updates the age statistic
func (c *Cache) UpdateAge() {
c.mu.RLock()
defer c.mu.RUnlock()
ageStat := new(expvar.Int)
ageStat.Set(int64(time.Now().Sub(c.lastSnapshot) / time.Millisecond))
c.statMap.Set(statCacheAgeMs, ageStat)
}
func (l *WAL) Remove(files []string) error {
l.mu.Lock()
defer l.mu.Unlock()
for _, fn := range files {
os.RemoveAll(fn)
}
// Refresh the on-disk size stats
segments, err := segmentFileNames(l.path)
if err != nil {
return err
}
var totalOldDiskSize int64
for _, seg := range segments {
stat, err := os.Stat(seg)
if err != nil {
return err
}
totalOldDiskSize += stat.Size()
}
sizeStat := new(expvar.Int)
sizeStat.Set(totalOldDiskSize)
l.statMap.Set(statWALOldBytes, sizeStat)
return nil
}
func determineProperties(sizes []int) *expvar.Map {
var sum int
props := new(expvar.Map).Init()
for _, n := range sizes {
sum += n
}
// Determine properties
sort.Ints(sizes)
if len(sizes) > 0 {
summary := map[string]int{
"min": sizes[0],
"max": sizes[len(sizes)-1],
"length": len(sizes),
"sum": sum,
"95e": sizes[int(float64(len(sizes))*0.95)],
}
mean := float64(sum) / float64(summary["length"])
// Pack them into an expvar Map
for k, v := range summary {
n := new(expvar.Int)
n.Set(int64(v))
props.Set(k, n)
}
avge := new(expvar.Float)
avge.Set(mean)
props.Set("avg", avge)
}
return props
}
func (g *goroutineTracker) recordSnapshot() {
g.mutex.Lock()
defer g.mutex.Unlock()
// get number of goroutines
numGoroutines := uint64(runtime.NumGoroutine())
// bump the high water mark
if numGoroutines > g.HighWaterMark {
g.HighWaterMark = numGoroutines
varInt := expvar.Int{}
varInt.Set(int64(numGoroutines))
base.StatsExpvars.Set("goroutines_highWaterMark", &varInt)
}
// append to history
g.Snapshots = append(g.Snapshots, numGoroutines)
// drop the oldest one if we've gone over the max
if len(g.Snapshots) > kMaxGoroutineSnapshots {
g.Snapshots = g.Snapshots[1:]
}
}
// Open opens and initializes the Log. Will recover from previous unclosed shutdowns
func (l *WAL) Open() error {
l.mu.Lock()
defer l.mu.Unlock()
if l.LoggingEnabled {
l.logger.Printf("tsm1 WAL starting with %d segment size\n", l.SegmentSize)
l.logger.Printf("tsm1 WAL writing to %s\n", l.path)
}
if err := os.MkdirAll(l.path, 0777); err != nil {
return err
}
segments, err := segmentFileNames(l.path)
if err != nil {
return err
}
if len(segments) > 0 {
lastSegment := segments[len(segments)-1]
id, err := idFromFileName(lastSegment)
if err != nil {
return err
}
l.currentSegmentID = id
stat, err := os.Stat(lastSegment)
if err != nil {
return err
}
if stat.Size() == 0 {
os.Remove(lastSegment)
segments = segments[:len(segments)-1]
}
if err := l.newSegmentFile(); err != nil {
return err
}
}
var totalOldDiskSize int64
for _, seg := range segments {
stat, err := os.Stat(seg)
if err != nil {
return err
}
totalOldDiskSize += stat.Size()
}
sizeStat := new(expvar.Int)
sizeStat.Set(totalOldDiskSize)
l.statMap.Set(statWALOldBytes, sizeStat)
l.closing = make(chan struct{})
l.lastWriteTime = time.Now()
return nil
}
// Update the snapshotsCount and the diskSize levels
func (c *Cache) updateSnapshots() {
// Update disk stats
diskSizeStat := new(expvar.Int)
diskSizeStat.Set(int64(c.snapshotSize))
c.statMap.Set(statCacheDiskBytes, diskSizeStat)
snapshotsStat := new(expvar.Int)
snapshotsStat.Set(int64(c.snapshotAttempts))
c.statMap.Set(statSnapshots, snapshotsStat)
}
func TestDuplicatePublish(t *testing.T) {
defer reset()
num1 := new(expvar.Int)
num1.Set(10)
Publish("number", num1)
num2 := new(expvar.Int)
num2.Set(20)
Publish("number", num2)
if g := Get("number").String(); g != "20" {
t.Errorf("number str = %s, want %s", g, "20")
}
}
// AddCount metrics
func AddCount(name string) {
updLastTime(name, time.Now())
var counter *ratecounter.RateCounter
counter, ok := counters[name]
if !ok {
counter = ratecounter.NewRateCounter(1 * time.Minute)
counters[name] = counter
}
var request *expvar.Int
request, ok = requests[name]
if !ok {
request = expvar.NewInt(name)
requests[name] = request
}
counter.Incr(1)
request.Set(counter.Rate())
}
func (l *WAL) writeToLog(entry WALEntry) (int, error) {
// encode and compress the entry while we're not locked
bytes := getBuf(walEncodeBufSize)
defer putBuf(bytes)
b, err := entry.Encode(bytes)
if err != nil {
return -1, err
}
encBuf := getBuf(snappy.MaxEncodedLen(len(b)))
defer putBuf(encBuf)
compressed := snappy.Encode(encBuf, b)
l.mu.Lock()
defer l.mu.Unlock()
// Make sure the log has not been closed
select {
case <-l.closing:
return -1, ErrWALClosed
default:
}
// roll the segment file if needed
if err := l.rollSegment(); err != nil {
return -1, fmt.Errorf("error rolling WAL segment: %v", err)
}
// write and sync
if err := l.currentSegmentWriter.Write(entry.Type(), compressed); err != nil {
return -1, fmt.Errorf("error writing WAL entry: %v", err)
}
// Update stats for current segment size
curSize := new(expvar.Int)
curSize.Set(int64(l.currentSegmentWriter.size))
l.statMap.Set(statWALCurrentBytes, curSize)
l.lastWriteTime = time.Now()
return l.currentSegmentID, l.currentSegmentWriter.sync()
}
func (s *Shard) monitorSize() {
t := time.NewTicker(monitorStatInterval)
defer t.Stop()
for {
select {
case <-s.closing:
return
case <-t.C:
size, err := s.DiskSize()
if err != nil {
s.logger.Printf("Error collecting shard size: %v", err)
continue
}
sizeStat := new(expvar.Int)
sizeStat.Set(size)
s.statMap.Set(statDiskBytes, sizeStat)
}
}
}
// newSegmentFile will close the current segment file and open a new one, updating bookkeeping info on the log
func (l *WAL) newSegmentFile() error {
l.currentSegmentID++
if l.currentSegmentWriter != nil {
if err := l.currentSegmentWriter.close(); err != nil {
return err
}
l.statMap.Add(statWALOldBytes, int64(l.currentSegmentWriter.size))
}
fileName := filepath.Join(l.path, fmt.Sprintf("%s%05d.%s", WALFilePrefix, l.currentSegmentID, WALFileExtension))
fd, err := os.OpenFile(fileName, os.O_CREATE|os.O_RDWR, 0666)
if err != nil {
return err
}
l.currentSegmentWriter = NewWALSegmentWriter(fd)
// Reset the current segment size stat
curSize := new(expvar.Int)
curSize.Set(0)
l.statMap.Set(statWALCurrentBytes, curSize)
return nil
}
func (r *routingTable) reachableNodes() (tbl map[string][]byte) {
tbl = make(map[string][]byte)
for addr, r := range r.addresses {
if addr == "" {
log.V(3).Infof("reachableNodes: found empty address for node %x.", r.id)
continue
}
if r.reachable && len(r.id) == 20 {
tbl[addr] = []byte(r.id)
}
}
hexId := fmt.Sprintf("%x", r.nodeId)
// This creates a new expvar everytime, but the alternative is too
// bothersome (get the current value, type cast it, ensure it
// exists..). Also I'm not using NewInt because I don't want to publish
// the value.
v := new(expvar.Int)
v.Set(int64(len(tbl)))
reachableNodes.Set(hexId, v)
return
}
func (f *FileStore) Replace(oldFiles, newFiles []string) error {
f.mu.Lock()
defer f.mu.Unlock()
f.lastModified = time.Now()
// Copy the current set of active files while we rename
// and load the new files. We copy the pointers here to minimize
// the time that locks are held as well as to ensure that the replacement
// is atomic.©
var updated []TSMFile
for _, t := range f.files {
updated = append(updated, t)
}
// Rename all the new files to make them live on restart
for _, file := range newFiles {
var newName = file
if strings.HasSuffix(file, ".tmp") {
// The new TSM files have a tmp extension. First rename them.
newName = file[:len(file)-4]
if err := os.Rename(file, newName); err != nil {
return err
}
}
fd, err := os.Open(newName)
if err != nil {
return err
}
tsm, err := NewTSMReader(fd)
if err != nil {
return err
}
updated = append(updated, tsm)
}
// We need to prune our set of active files now
var active []TSMFile
for _, file := range updated {
keep := true
for _, remove := range oldFiles {
if remove == file.Path() {
keep = false
if err := file.Close(); err != nil {
return err
}
if err := file.Remove(); err != nil {
return err
}
break
}
}
if keep {
active = append(active, file)
}
}
if err := syncDir(f.dir); err != nil {
return err
}
f.files = active
sort.Sort(tsmReaders(f.files))
// Recalculate the disk size stat
var totalSize int64
for _, file := range f.files {
totalSize += int64(file.Size())
}
sizeStat := new(expvar.Int)
sizeStat.Set(totalSize)
f.statMap.Set(statFileStoreBytes, sizeStat)
return nil
}
func ExampleExpvarCollector() {
expvarCollector := prometheus.NewExpvarCollector(map[string]*prometheus.Desc{
"memstats": prometheus.NewDesc(
"expvar_memstats",
"All numeric memstats as one metric family. Not a good role-model, actually... ;-)",
[]string{"type"}, nil,
),
"lone-int": prometheus.NewDesc(
"expvar_lone_int",
"Just an expvar int as an example.",
nil, nil,
),
"http-request-map": prometheus.NewDesc(
"expvar_http_request_total",
"How many http requests processed, partitioned by status code and http method.",
[]string{"code", "method"}, nil,
),
})
prometheus.MustRegister(expvarCollector)
// The Prometheus part is done here. But to show that this example is
// doing anything, we have to manually export something via expvar. In
// real-life use-cases, some library would already have exported via
// expvar what we want to re-export as Prometheus metrics.
expvar.NewInt("lone-int").Set(42)
expvarMap := expvar.NewMap("http-request-map")
var (
expvarMap1, expvarMap2 expvar.Map
expvarInt11, expvarInt12, expvarInt21, expvarInt22 expvar.Int
)
expvarMap1.Init()
expvarMap2.Init()
expvarInt11.Set(3)
expvarInt12.Set(13)
expvarInt21.Set(11)
expvarInt22.Set(212)
expvarMap1.Set("POST", &expvarInt11)
expvarMap1.Set("GET", &expvarInt12)
expvarMap2.Set("POST", &expvarInt21)
expvarMap2.Set("GET", &expvarInt22)
expvarMap.Set("404", &expvarMap1)
expvarMap.Set("200", &expvarMap2)
// Results in the following expvar map:
// "http-request-count": {"200": {"POST": 11, "GET": 212}, "404": {"POST": 3, "GET": 13}}
// Let's see what the scrape would yield, but exclude the memstats metrics.
metricStrings := []string{}
metric := dto.Metric{}
metricChan := make(chan prometheus.Metric)
go func() {
expvarCollector.Collect(metricChan)
close(metricChan)
}()
for m := range metricChan {
if strings.Index(m.Desc().String(), "expvar_memstats") == -1 {
metric.Reset()
m.Write(&metric)
metricStrings = append(metricStrings, metric.String())
}
}
sort.Strings(metricStrings)
for _, s := range metricStrings {
fmt.Println(strings.TrimRight(s, " "))
}
// Output:
// label:<name:"code" value:"200" > label:<name:"method" value:"GET" > untyped:<value:212 >
// label:<name:"code" value:"200" > label:<name:"method" value:"POST" > untyped:<value:11 >
// label:<name:"code" value:"404" > label:<name:"method" value:"GET" > untyped:<value:13 >
// label:<name:"code" value:"404" > label:<name:"method" value:"POST" > untyped:<value:3 >
// untyped:<value:42 >
}