go-ethereum/metrics/metrics.go
2019-03-25 10:40:46 +02:00

112 lines
4.3 KiB
Go

// Go port of Coda Hale's Metrics library
//
// <https://github.com/rcrowley/go-metrics>
//
// Coda Hale's original work: <https://github.com/codahale/metrics>
package metrics
import (
"os"
"runtime"
"strings"
"time"
"github.com/ethereum/go-ethereum/log"
)
// Enabled is checked by the constructor functions for all of the
// standard metrics. If it is true, the metric returned is a stub.
//
// This global kill-switch helps quantify the observer effect and makes
// for less cluttered pprof profiles.
var Enabled = false
// EnabledExpensive is a soft-flag meant for external packages to check if costly
// metrics gathering is allowed or not. The goal is to separate standard metrics
// for health monitoring and debug metrics that might impact runtime performance.
var EnabledExpensive = false
// enablerFlags is the CLI flag names to use to enable metrics collections.
var enablerFlags = []string{"metrics", "dashboard"}
// expensiveEnablerFlags is the CLI flag names to use to enable metrics collections.
var expensiveEnablerFlags = []string{"metrics.expensive"}
// Init enables or disables the metrics system. Since we need this to run before
// any other code gets to create meters and timers, we'll actually do an ugly hack
// and peek into the command line args for the metrics flag.
func init() {
for _, arg := range os.Args {
flag := strings.TrimLeft(arg, "-")
for _, enabler := range enablerFlags {
if !Enabled && flag == enabler {
log.Info("Enabling metrics collection")
Enabled = true
}
}
for _, enabler := range expensiveEnablerFlags {
if !EnabledExpensive && flag == enabler {
log.Info("Enabling expensive metrics collection")
EnabledExpensive = true
}
}
}
}
// CollectProcessMetrics periodically collects various metrics about the running
// process.
func CollectProcessMetrics(refresh time.Duration) {
// Short circuit if the metrics system is disabled
if !Enabled {
return
}
// Create the various data collectors
memstats := make([]*runtime.MemStats, 2)
diskstats := make([]*DiskStats, 2)
for i := 0; i < len(memstats); i++ {
memstats[i] = new(runtime.MemStats)
diskstats[i] = new(DiskStats)
}
// Define the various metrics to collect
memAllocs := GetOrRegisterMeter("system/memory/allocs", DefaultRegistry)
memFrees := GetOrRegisterMeter("system/memory/frees", DefaultRegistry)
memInuse := GetOrRegisterMeter("system/memory/inuse", DefaultRegistry)
memPauses := GetOrRegisterMeter("system/memory/pauses", DefaultRegistry)
var diskReads, diskReadBytes, diskWrites, diskWriteBytes Meter
var diskReadBytesCounter, diskWriteBytesCounter Counter
if err := ReadDiskStats(diskstats[0]); err == nil {
diskReads = GetOrRegisterMeter("system/disk/readcount", DefaultRegistry)
diskReadBytes = GetOrRegisterMeter("system/disk/readdata", DefaultRegistry)
diskReadBytesCounter = GetOrRegisterCounter("system/disk/readbytes", DefaultRegistry)
diskWrites = GetOrRegisterMeter("system/disk/writecount", DefaultRegistry)
diskWriteBytes = GetOrRegisterMeter("system/disk/writedata", DefaultRegistry)
diskWriteBytesCounter = GetOrRegisterCounter("system/disk/writebytes", DefaultRegistry)
} else {
log.Debug("Failed to read disk metrics", "err", err)
}
// Iterate loading the different stats and updating the meters
for i := 1; ; i++ {
location1 := i % 2
location2 := (i - 1) % 2
runtime.ReadMemStats(memstats[location1])
memAllocs.Mark(int64(memstats[location1].Mallocs - memstats[location2].Mallocs))
memFrees.Mark(int64(memstats[location1].Frees - memstats[location2].Frees))
memInuse.Mark(int64(memstats[location1].Alloc - memstats[location2].Alloc))
memPauses.Mark(int64(memstats[location1].PauseTotalNs - memstats[location2].PauseTotalNs))
if ReadDiskStats(diskstats[location1]) == nil {
diskReads.Mark(diskstats[location1].ReadCount - diskstats[location2].ReadCount)
diskReadBytes.Mark(diskstats[location1].ReadBytes - diskstats[location2].ReadBytes)
diskWrites.Mark(diskstats[location1].WriteCount - diskstats[location2].WriteCount)
diskWriteBytes.Mark(diskstats[location1].WriteBytes - diskstats[location2].WriteBytes)
diskReadBytesCounter.Inc(diskstats[location1].ReadBytes - diskstats[location2].ReadBytes)
diskWriteBytesCounter.Inc(diskstats[location1].WriteBytes - diskstats[location2].WriteBytes)
}
time.Sleep(refresh)
}
}