github.com/daeglee/go-ethereum@v0.0.0-20190504220456-cad3e8d18e9b/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 = false
    23  
    24  // EnabledExpensive is a soft-flag meant for external packages to check if costly
    25  // metrics gathering is allowed or not. The goal is to separate standard metrics
    26  // for health monitoring and debug metrics that might impact runtime performance.
    27  var EnabledExpensive = false
    28  
    29  // enablerFlags is the CLI flag names to use to enable metrics collections.
    30  var enablerFlags = []string{"metrics", "dashboard"}
    31  
    32  // expensiveEnablerFlags is the CLI flag names to use to enable metrics collections.
    33  var expensiveEnablerFlags = []string{"metrics.expensive"}
    34  
    35  // Init enables or disables the metrics system. Since we need this to run before
    36  // any other code gets to create meters and timers, we'll actually do an ugly hack
    37  // and peek into the command line args for the metrics flag.
    38  func init() {
    39  	for _, arg := range os.Args {
    40  		flag := strings.TrimLeft(arg, "-")
    41  
    42  		for _, enabler := range enablerFlags {
    43  			if !Enabled && flag == enabler {
    44  				log.Info("Enabling metrics collection")
    45  				Enabled = true
    46  			}
    47  		}
    48  		for _, enabler := range expensiveEnablerFlags {
    49  			if !EnabledExpensive && flag == enabler {
    50  				log.Info("Enabling expensive metrics collection")
    51  				EnabledExpensive = true
    52  			}
    53  		}
    54  	}
    55  }
    56  
    57  // CollectProcessMetrics periodically collects various metrics about the running
    58  // process.
    59  func CollectProcessMetrics(refresh time.Duration) {
    60  	// Short circuit if the metrics system is disabled
    61  	if !Enabled {
    62  		return
    63  	}
    64  	// Create the various data collectors
    65  	memstats := make([]*runtime.MemStats, 2)
    66  	diskstats := make([]*DiskStats, 2)
    67  	for i := 0; i < len(memstats); i++ {
    68  		memstats[i] = new(runtime.MemStats)
    69  		diskstats[i] = new(DiskStats)
    70  	}
    71  	// Define the various metrics to collect
    72  	memAllocs := GetOrRegisterMeter("system/memory/allocs", DefaultRegistry)
    73  	memFrees := GetOrRegisterMeter("system/memory/frees", DefaultRegistry)
    74  	memInuse := GetOrRegisterMeter("system/memory/inuse", DefaultRegistry)
    75  	memPauses := GetOrRegisterMeter("system/memory/pauses", DefaultRegistry)
    76  
    77  	var diskReads, diskReadBytes, diskWrites, diskWriteBytes Meter
    78  	var diskReadBytesCounter, diskWriteBytesCounter Counter
    79  	if err := ReadDiskStats(diskstats[0]); err == nil {
    80  		diskReads = GetOrRegisterMeter("system/disk/readcount", DefaultRegistry)
    81  		diskReadBytes = GetOrRegisterMeter("system/disk/readdata", DefaultRegistry)
    82  		diskReadBytesCounter = GetOrRegisterCounter("system/disk/readbytes", DefaultRegistry)
    83  		diskWrites = GetOrRegisterMeter("system/disk/writecount", DefaultRegistry)
    84  		diskWriteBytes = GetOrRegisterMeter("system/disk/writedata", DefaultRegistry)
    85  		diskWriteBytesCounter = GetOrRegisterCounter("system/disk/writebytes", DefaultRegistry)
    86  	} else {
    87  		log.Debug("Failed to read disk metrics", "err", err)
    88  	}
    89  	// Iterate loading the different stats and updating the meters
    90  	for i := 1; ; i++ {
    91  		location1 := i % 2
    92  		location2 := (i - 1) % 2
    93  
    94  		runtime.ReadMemStats(memstats[location1])
    95  		memAllocs.Mark(int64(memstats[location1].Mallocs - memstats[location2].Mallocs))
    96  		memFrees.Mark(int64(memstats[location1].Frees - memstats[location2].Frees))
    97  		memInuse.Mark(int64(memstats[location1].Alloc - memstats[location2].Alloc))
    98  		memPauses.Mark(int64(memstats[location1].PauseTotalNs - memstats[location2].PauseTotalNs))
    99  
   100  		if ReadDiskStats(diskstats[location1]) == nil {
   101  			diskReads.Mark(diskstats[location1].ReadCount - diskstats[location2].ReadCount)
   102  			diskReadBytes.Mark(diskstats[location1].ReadBytes - diskstats[location2].ReadBytes)
   103  			diskWrites.Mark(diskstats[location1].WriteCount - diskstats[location2].WriteCount)
   104  			diskWriteBytes.Mark(diskstats[location1].WriteBytes - diskstats[location2].WriteBytes)
   105  
   106  			diskReadBytesCounter.Inc(diskstats[location1].ReadBytes - diskstats[location2].ReadBytes)
   107  			diskWriteBytesCounter.Inc(diskstats[location1].WriteBytes - diskstats[location2].WriteBytes)
   108  		}
   109  		time.Sleep(refresh)
   110  	}
   111  }