// getProcFDUsage returns file descriptor usage information for the process
// identified by the given PID. If the feature is not implemented then nil
// is returned with no error. If there is a permission error while reading the
// data then nil is returned with no error (/proc/[pid]/fd requires root
// permissions). Any other errors that occur are returned.
func getProcFDUsage(pid int) (*sigar.ProcFDUsage, error) {
fd := sigar.ProcFDUsage{}
if err := fd.Get(pid); err != nil {
switch {
case sigar.IsNotImplemented(err):
return nil, nil
case os.IsPermission(err):
return nil, nil
default:
return nil, err
}
}
return &fd, nil
}
// getProcFDUsage returns file descriptor usage information for the process
// identified by the given PID. If the feature is not implemented then nil
// is returned with no error. If there is a permission error while reading the
// data then nil is returned with no error (/proc/[pid]/fd requires root
// permissions). Any other errors that occur are returned.
func getProcFDUsage(pid int) (*sigar.ProcFDUsage, error) {
// It's not possible to collect FD usage from other processes on FreeBSD
// due to linprocfs not exposing the information.
if runtime.GOOS == "freebsd" && pid != os.Getpid() {
return nil, nil
}
fd := sigar.ProcFDUsage{}
if err := fd.Get(pid); err != nil {
switch {
case sigar.IsNotImplemented(err):
return nil, nil
case os.IsPermission(err):
return nil, nil
default:
return nil, err
}
}
return &fd, nil
}
// SampleEnvironment queries the runtime system for various interesting metrics,
// storing the resulting values in the set of metric gauges maintained by
// RuntimeStatSampler. This makes runtime statistics more convenient for
// consumption by the time series and status systems.
//
// This method should be called periodically by a higher level system in order
// to keep runtime statistics current.
func (rsr *RuntimeStatSampler) SampleEnvironment() {
// Record memory and call stats from the runtime package.
// TODO(mrtracy): memory statistics will not include usage from RocksDB.
// Determine an appropriate way to compute total memory usage.
numCgoCall := runtime.NumCgoCall()
numGoroutine := runtime.NumGoroutine()
// It might be useful to call ReadMemStats() more often, but it stops the
// world while collecting stats so shouldn't be called too often.
// NOTE: the MemStats fields do not get decremented when memory is released,
// to get accurate numbers, be sure to subtract. eg: ms.Sys - ms.HeapReleased for
// current memory reserved.
ms := runtime.MemStats{}
runtime.ReadMemStats(&ms)
// Retrieve Mem and CPU statistics.
pid := os.Getpid()
mem := gosigar.ProcMem{}
if err := mem.Get(pid); err != nil {
log.Errorf(context.TODO(), "unable to get mem usage: %v", err)
}
cpu := gosigar.ProcTime{}
if err := cpu.Get(pid); err != nil {
log.Errorf(context.TODO(), "unable to get cpu usage: %v", err)
}
fds := gosigar.ProcFDUsage{}
if err := fds.Get(pid); err != nil {
if _, ok := err.(gosigar.ErrNotImplemented); ok {
if !rsr.fdUsageNotImplemented {
rsr.fdUsageNotImplemented = true
log.Errorf(context.TODO(), "unable to get file descriptor usage (will not try again): %s", err)
}
} else {
log.Errorf(context.TODO(), "unable to get file descriptor usage: %s", err)
}
}
// Time statistics can be compared to the total elapsed time to create a
// useful percentage of total CPU usage, which would be somewhat less accurate
// if calculated later using downsampled time series data.
now := rsr.clock.PhysicalNow()
dur := float64(now - rsr.lastNow)
// cpu.{User,Sys} are in milliseconds, convert to nanoseconds.
newUtime := int64(cpu.User) * 1e6
newStime := int64(cpu.Sys) * 1e6
uPerc := float64(newUtime-rsr.lastUtime) / dur
sPerc := float64(newStime-rsr.lastStime) / dur
pausePerc := float64(ms.PauseTotalNs-rsr.lastPauseTime) / dur
rsr.lastNow = now
rsr.lastUtime = newUtime
rsr.lastStime = newStime
rsr.lastPauseTime = ms.PauseTotalNs
var cgoAllocated, cgoTotal uint64
if getCgoMemStats != nil {
var err error
cgoAllocated, cgoTotal, err = getCgoMemStats()
if err != nil {
log.Warningf(context.TODO(), "problem fetching CGO memory stats: %s, CGO stats will be empty.", err)
}
}
goAllocated := ms.Alloc
goTotal := ms.Sys - ms.HeapReleased
// Log summary of statistics to console.
cgoRate := float64((numCgoCall-rsr.lastCgoCall)*int64(time.Second)) / dur
log.Infof(context.TODO(), "runtime stats: %s RSS, %d goroutines, %s/%s/%s GO alloc/idle/total, %s/%s CGO alloc/total, %.2fcgo/sec, %.2f/%.2f %%(u/s)time, %.2f %%gc (%dx)",
humanize.IBytes(mem.Resident), numGoroutine,
humanize.IBytes(goAllocated), humanize.IBytes(ms.HeapIdle-ms.HeapReleased), humanize.IBytes(goTotal),
humanize.IBytes(cgoAllocated), humanize.IBytes(cgoTotal),
cgoRate, uPerc, sPerc, pausePerc, ms.NumGC-rsr.lastNumGC)
if log.V(2) {
log.Infof(context.TODO(), "memstats: %+v", ms)
}
rsr.lastCgoCall = numCgoCall
rsr.lastNumGC = ms.NumGC
rsr.CgoCalls.Update(numCgoCall)
rsr.Goroutines.Update(int64(numGoroutine))
rsr.GoAllocBytes.Update(int64(goAllocated))
rsr.GoTotalBytes.Update(int64(goTotal))
rsr.CgoAllocBytes.Update(int64(cgoAllocated))
rsr.CgoTotalBytes.Update(int64(cgoTotal))
rsr.GcCount.Update(int64(ms.NumGC))
rsr.GcPauseNS.Update(int64(ms.PauseTotalNs))
rsr.GcPausePercent.Update(pausePerc)
rsr.CPUUserNS.Update(newUtime)
rsr.CPUUserPercent.Update(uPerc)
rsr.CPUSysNS.Update(newStime)
rsr.CPUSysPercent.Update(sPerc)
rsr.FDOpen.Update(int64(fds.Open))
rsr.FDSoftLimit.Update(int64(fds.SoftLimit))
rsr.Rss.Update(int64(mem.Resident))
rsr.Uptime.Update((now - rsr.startTimeNanos) / 1e9)
}