// for debugging, show goroutine trace on receipt of USR1. uninstall by calling
// Stop on the returned object
func InstallStackTracer() stopper.Stopper {
signals := make(chan os.Signal, 1)
signal.Notify(signals, traceSignal)
stopper := stopper.NewChanStopper()
go func() {
defer func() {
signal.Stop(signals)
close(signals)
}()
for {
select {
case <-signals:
log.Print(instrumentation.GetStackTrace(true))
case <-stopper.Chan:
return
}
}
}()
return stopper
}
// NewGangliaReporterWithOptions is NewGangliaReporter with the groupName.
func NewGangliaReporterWithOptions(interval time.Duration, groupName string) *Reporter {
gm, err := NewGmetric()
if err != nil {
vlog.VLogfQuiet("ganglia", "Couldn't start Ganglia reporter: %s", err)
return nil
} else if gm == nil {
return nil
}
stopper := stopper.NewChanStopper()
gr := &Reporter{
ChanStopper: stopper,
prefix: "",
callbacks: []ReporterCallback{},
previous: make(map[string]gmetricSample),
groupName: groupName,
dmax: 0,
}
go func() {
defer stopper.Done()
for {
select {
case <-stopper.Chan:
return
case <-time.After(interval):
go func() {
// SendMetric "opens" and "closes" UDP connections each
// time, but since we expect the callback to send several
// metrics at once, avoid that here.
conns := gm.OpenConnections()
n := 0
sender := func(name string, value string, metricType uint32, units string, rate bool) {
v := value
if rate {
prev, exists := gr.previous[name]
units += "/sec"
now := time.Now()
switch metricType {
case Ushort, Short, Uint, Int:
i, err := strconv.Atoi(value)
if err != nil {
vlog.VLogfQuiet(name, "Value %q doesn't look like an int: %s", value, err)
return
}
gr.previous[name] = gmetricSample{i, now}
if !exists {
return
}
delta := i - prev.value.(int)
elapsed := time.Now().Sub(prev.when).Seconds()
v = fmt.Sprint(float64(delta) / elapsed)
// upgrade to a float to avoid loss of precision
metricType = Float
case Float, Double:
f, err := strconv.ParseFloat(value, 64)
if err != nil {
vlog.VLogfQuiet(name, "Value %q doesn't look like a float: %s", value, err)
return
}
gr.previous[name] = gmetricSample{f, now}
if !exists {
return
}
delta := f - prev.value.(float64)
elapsed := time.Now().Sub(prev.when).Seconds()
v = fmt.Sprint(delta / elapsed)
case String:
vlog.VLogfQuiet(name, "Can't compute deltas for string metric %q", value)
return
}
}
// gmetad fails to escape quotes, eventually generating
// invalid xml. do it here as a workaround.
v = html.EscapeString(v)
name = html.EscapeString(name)
units = html.EscapeString(units)
n++
gm.SendMetricPackets(
gr.prefix+name, v, metricType, units,
gmetric.SLOPE_BOTH,
uint32(interval.Seconds()), // tmax is the expected reporting interval
gr.dmax,
gr.groupName,
gmetric.PACKET_BOTH, conns,
)
if debug.On() {
if rate {
log.Printf("gmetric: name=%q, rate=%q, value=%q, type=%d, units=%q, slope=%d, tmax=%d, dmax=%v, group=%q, packet=%d",
gr.prefix+name, v, value, metricType, units, gmetric.SLOPE_BOTH,
uint32(interval.Seconds()), gr.dmax, gr.groupName, gmetric.PACKET_BOTH,
)
} else {
log.Printf("gmetric: name=%q, value=%q, type=%d, units=%q, slope=%d, tmax=%d, dmax=%v, group=%q, packet=%d",
gr.prefix+name, v, metricType, units, gmetric.SLOPE_BOTH,
uint32(interval.Seconds()), gr.dmax, gr.groupName, gmetric.PACKET_BOTH,
)
}
}
}
defer gm.CloseConnections(conns)
for _, callback := range gr.callbacks {
callback(sender)
}
if debug.On() {
log.Printf("Published %d metrics to Ganglia", n)
}
}()
}
}
}()
return gr
}