metrics: pull library and introduce ResettingTimer and InfluxDB reporter (#15910)

* go-metrics: fork library and introduce ResettingTimer and InfluxDB reporter.

* vendor: change nonsense/go-metrics to ethersphere/go-metrics

* go-metrics: add tests. move ResettingTimer logic from reporter to type.

* all, metrics: pull in metrics package in go-ethereum

* metrics/test: make sure metrics are enabled for tests

* metrics: apply gosimple rules

* metrics/exp, internal/debug: init expvar endpoint when starting pprof server

* internal/debug: tiny comment formatting fix

1 files changed, 113 insertions, 0 deletions

diff --git a/metrics/graphite.go b/metrics/graphite.go
new file mode 100644
index 000000000..142eec86b
--- /dev/null
+++ b/metrics/graphite.go
@@ -0,0 +1,113 @@
+package metrics
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"net"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// GraphiteConfig provides a container with configuration parameters for
+// the Graphite exporter
+type GraphiteConfig struct {
+	Addr          *net.TCPAddr  // Network address to connect to
+	Registry      Registry      // Registry to be exported
+	FlushInterval time.Duration // Flush interval
+	DurationUnit  time.Duration // Time conversion unit for durations
+	Prefix        string        // Prefix to be prepended to metric names
+	Percentiles   []float64     // Percentiles to export from timers and histograms
+}
+
+// Graphite is a blocking exporter function which reports metrics in r
+// to a graphite server located at addr, flushing them every d duration
+// and prepending metric names with prefix.
+func Graphite(r Registry, d time.Duration, prefix string, addr *net.TCPAddr) {
+	GraphiteWithConfig(GraphiteConfig{
+		Addr:          addr,
+		Registry:      r,
+		FlushInterval: d,
+		DurationUnit:  time.Nanosecond,
+		Prefix:        prefix,
+		Percentiles:   []float64{0.5, 0.75, 0.95, 0.99, 0.999},
+	})
+}
+
+// GraphiteWithConfig is a blocking exporter function just like Graphite,
+// but it takes a GraphiteConfig instead.
+func GraphiteWithConfig(c GraphiteConfig) {
+	log.Printf("WARNING: This go-metrics client has been DEPRECATED! It has been moved to https://github.com/cyberdelia/go-metrics-graphite and will be removed from rcrowley/go-metrics on August 12th 2015")
+	for range time.Tick(c.FlushInterval) {
+		if err := graphite(&c); nil != err {
+			log.Println(err)
+		}
+	}
+}
+
+// GraphiteOnce performs a single submission to Graphite, returning a
+// non-nil error on failed connections. This can be used in a loop
+// similar to GraphiteWithConfig for custom error handling.
+func GraphiteOnce(c GraphiteConfig) error {
+	log.Printf("WARNING: This go-metrics client has been DEPRECATED! It has been moved to https://github.com/cyberdelia/go-metrics-graphite and will be removed from rcrowley/go-metrics on August 12th 2015")
+	return graphite(&c)
+}
+
+func graphite(c *GraphiteConfig) error {
+	now := time.Now().Unix()
+	du := float64(c.DurationUnit)
+	conn, err := net.DialTCP("tcp", nil, c.Addr)
+	if nil != err {
+		return err
+	}
+	defer conn.Close()
+	w := bufio.NewWriter(conn)
+	c.Registry.Each(func(name string, i interface{}) {
+		switch metric := i.(type) {
+		case Counter:
+			fmt.Fprintf(w, "%s.%s.count %d %d\n", c.Prefix, name, metric.Count(), now)
+		case Gauge:
+			fmt.Fprintf(w, "%s.%s.value %d %d\n", c.Prefix, name, metric.Value(), now)
+		case GaugeFloat64:
+			fmt.Fprintf(w, "%s.%s.value %f %d\n", c.Prefix, name, metric.Value(), now)
+		case Histogram:
+			h := metric.Snapshot()
+			ps := h.Percentiles(c.Percentiles)
+			fmt.Fprintf(w, "%s.%s.count %d %d\n", c.Prefix, name, h.Count(), now)
+			fmt.Fprintf(w, "%s.%s.min %d %d\n", c.Prefix, name, h.Min(), now)
+			fmt.Fprintf(w, "%s.%s.max %d %d\n", c.Prefix, name, h.Max(), now)
+			fmt.Fprintf(w, "%s.%s.mean %.2f %d\n", c.Prefix, name, h.Mean(), now)
+			fmt.Fprintf(w, "%s.%s.std-dev %.2f %d\n", c.Prefix, name, h.StdDev(), now)
+			for psIdx, psKey := range c.Percentiles {
+				key := strings.Replace(strconv.FormatFloat(psKey*100.0, 'f', -1, 64), ".", "", 1)
+				fmt.Fprintf(w, "%s.%s.%s-percentile %.2f %d\n", c.Prefix, name, key, ps[psIdx], now)
+			}
+		case Meter:
+			m := metric.Snapshot()
+			fmt.Fprintf(w, "%s.%s.count %d %d\n", c.Prefix, name, m.Count(), now)
+			fmt.Fprintf(w, "%s.%s.one-minute %.2f %d\n", c.Prefix, name, m.Rate1(), now)
+			fmt.Fprintf(w, "%s.%s.five-minute %.2f %d\n", c.Prefix, name, m.Rate5(), now)
+			fmt.Fprintf(w, "%s.%s.fifteen-minute %.2f %d\n", c.Prefix, name, m.Rate15(), now)
+			fmt.Fprintf(w, "%s.%s.mean %.2f %d\n", c.Prefix, name, m.RateMean(), now)
+		case Timer:
+			t := metric.Snapshot()
+			ps := t.Percentiles(c.Percentiles)
+			fmt.Fprintf(w, "%s.%s.count %d %d\n", c.Prefix, name, t.Count(), now)
+			fmt.Fprintf(w, "%s.%s.min %d %d\n", c.Prefix, name, t.Min()/int64(du), now)
+			fmt.Fprintf(w, "%s.%s.max %d %d\n", c.Prefix, name, t.Max()/int64(du), now)
+			fmt.Fprintf(w, "%s.%s.mean %.2f %d\n", c.Prefix, name, t.Mean()/du, now)
+			fmt.Fprintf(w, "%s.%s.std-dev %.2f %d\n", c.Prefix, name, t.StdDev()/du, now)
+			for psIdx, psKey := range c.Percentiles {
+				key := strings.Replace(strconv.FormatFloat(psKey*100.0, 'f', -1, 64), ".", "", 1)
+				fmt.Fprintf(w, "%s.%s.%s-percentile %.2f %d\n", c.Prefix, name, key, ps[psIdx], now)
+			}
+			fmt.Fprintf(w, "%s.%s.one-minute %.2f %d\n", c.Prefix, name, t.Rate1(), now)
+			fmt.Fprintf(w, "%s.%s.five-minute %.2f %d\n", c.Prefix, name, t.Rate5(), now)
+			fmt.Fprintf(w, "%s.%s.fifteen-minute %.2f %d\n", c.Prefix, name, t.Rate15(), now)
+			fmt.Fprintf(w, "%s.%s.mean-rate %.2f %d\n", c.Prefix, name, t.RateMean(), now)
+		}
+		w.Flush()
+	})
+	return nil
+}