github.com/clem109/go-ethereum@v1.8.3-0.20180316121352-fe6cf00f480a/metrics/metrics.go (about)

     1  // Go port of Coda Hale's Metrics library
     2  //
     3  // <https://github.com/rcrowley/go-metrics>
     4  //
     5  // Coda Hale's original work: <https://github.com/codahale/metrics>
     6  package metrics
     7  
     8  import (
     9  	"os"
    10  	"runtime"
    11  	"strings"
    12  	"time"
    13  
    14  	"github.com/ethereum/go-ethereum/log"
    15  )
    16  
    17  // Enabled is checked by the constructor functions for all of the
    18  // standard metrics.  If it is true, the metric returned is a stub.
    19  //
    20  // This global kill-switch helps quantify the observer effect and makes
    21  // for less cluttered pprof profiles.
    22  var Enabled bool = false
    23  
    24  // MetricsEnabledFlag is the CLI flag name to use to enable metrics collections.
    25  const MetricsEnabledFlag = "metrics"
    26  const DashboardEnabledFlag = "dashboard"
    27  
    28  // Init enables or disables the metrics system. Since we need this to run before
    29  // any other code gets to create meters and timers, we'll actually do an ugly hack
    30  // and peek into the command line args for the metrics flag.
    31  func init() {
    32  	for _, arg := range os.Args {
    33  		if flag := strings.TrimLeft(arg, "-"); flag == MetricsEnabledFlag || flag == DashboardEnabledFlag {
    34  			log.Info("Enabling metrics collection")
    35  			Enabled = true
    36  		}
    37  	}
    38  }
    39  
    40  // CollectProcessMetrics periodically collects various metrics about the running
    41  // process.
    42  func CollectProcessMetrics(refresh time.Duration) {
    43  	// Short circuit if the metrics system is disabled
    44  	if !Enabled {
    45  		return
    46  	}
    47  	// Create the various data collectors
    48  	memstats := make([]*runtime.MemStats, 2)
    49  	diskstats := make([]*DiskStats, 2)
    50  	for i := 0; i < len(memstats); i++ {
    51  		memstats[i] = new(runtime.MemStats)
    52  		diskstats[i] = new(DiskStats)
    53  	}
    54  	// Define the various metrics to collect
    55  	memAllocs := GetOrRegisterMeter("system/memory/allocs", DefaultRegistry)
    56  	memFrees := GetOrRegisterMeter("system/memory/frees", DefaultRegistry)
    57  	memInuse := GetOrRegisterMeter("system/memory/inuse", DefaultRegistry)
    58  	memPauses := GetOrRegisterMeter("system/memory/pauses", DefaultRegistry)
    59  
    60  	var diskReads, diskReadBytes, diskWrites, diskWriteBytes Meter
    61  	if err := ReadDiskStats(diskstats[0]); err == nil {
    62  		diskReads = GetOrRegisterMeter("system/disk/readcount", DefaultRegistry)
    63  		diskReadBytes = GetOrRegisterMeter("system/disk/readdata", DefaultRegistry)
    64  		diskWrites = GetOrRegisterMeter("system/disk/writecount", DefaultRegistry)
    65  		diskWriteBytes = GetOrRegisterMeter("system/disk/writedata", DefaultRegistry)
    66  	} else {
    67  		log.Debug("Failed to read disk metrics", "err", err)
    68  	}
    69  	// Iterate loading the different stats and updating the meters
    70  	for i := 1; ; i++ {
    71  		runtime.ReadMemStats(memstats[i%2])
    72  		memAllocs.Mark(int64(memstats[i%2].Mallocs - memstats[(i-1)%2].Mallocs))
    73  		memFrees.Mark(int64(memstats[i%2].Frees - memstats[(i-1)%2].Frees))
    74  		memInuse.Mark(int64(memstats[i%2].Alloc - memstats[(i-1)%2].Alloc))
    75  		memPauses.Mark(int64(memstats[i%2].PauseTotalNs - memstats[(i-1)%2].PauseTotalNs))
    76  
    77  		if ReadDiskStats(diskstats[i%2]) == nil {
    78  			diskReads.Mark(diskstats[i%2].ReadCount - diskstats[(i-1)%2].ReadCount)
    79  			diskReadBytes.Mark(diskstats[i%2].ReadBytes - diskstats[(i-1)%2].ReadBytes)
    80  			diskWrites.Mark(diskstats[i%2].WriteCount - diskstats[(i-1)%2].WriteCount)
    81  			diskWriteBytes.Mark(diskstats[i%2].WriteBytes - diskstats[(i-1)%2].WriteBytes)
    82  		}
    83  		time.Sleep(refresh)
    84  	}
    85  }