Merge pull request #82 from prometheus/beorn7/histogram

Add a histogram to the random example.
This commit is contained in:
Björn Rabenstein 2015-02-23 16:36:40 +01:00
commit 764e6a72c3
1 changed files with 20 additions and 6 deletions

View File

@ -29,8 +29,8 @@ import (
var ( var (
addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.") addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
uniformDomain = flag.Float64("uniform.domain", 200, "The domain for the uniform distribution.") uniformDomain = flag.Float64("uniform.domain", 200, "The domain for the uniform distribution.")
normDomain = flag.Float64("exponential.domain", 200, "The domain for the normal distribution.") normDomain = flag.Float64("normal.domain", 200, "The domain for the normal distribution.")
normMean = flag.Float64("exponential.mean", 10, "The mean for the normal distribution.") normMean = flag.Float64("normal.mean", 10, "The mean for the normal distribution.")
oscillationPeriod = flag.Duration("oscillation-period", 10*time.Minute, "The duration of the rate oscillation period.") oscillationPeriod = flag.Duration("oscillation-period", 10*time.Minute, "The duration of the rate oscillation period.")
) )
@ -45,11 +45,21 @@ var (
}, },
[]string{"service"}, []string{"service"},
) )
// The same as above, but now as a histogram, and only for the normal
// distribution. The buckets are targeted to the parameters of the
// normal distribution, with 20 buckets centered on the mean, each
// half-sigma wide.
rpcDurationsHistogram = prometheus.NewHistogram(prometheus.HistogramOpts{
Name: "rpc_durations_histogram_microseconds",
Help: "RPC latency distributions.",
Buckets: prometheus.LinearBuckets(*normMean-5**normDomain, .5**normDomain, 20),
})
) )
func init() { func init() {
// Register the summary with Prometheus's default registry. // Register the summary and the histogram with Prometheus's default registry.
prometheus.MustRegister(rpcDurations) prometheus.MustRegister(rpcDurations)
prometheus.MustRegister(rpcDurationsHistogram)
} }
func main() { func main() {
@ -64,21 +74,25 @@ func main() {
// Periodically record some sample latencies for the three services. // Periodically record some sample latencies for the three services.
go func() { go func() {
for { for {
rpcDurations.WithLabelValues("uniform").Observe(rand.Float64() * *uniformDomain) v := rand.Float64() * *uniformDomain
rpcDurations.WithLabelValues("uniform").Observe(v)
time.Sleep(time.Duration(100*oscillationFactor()) * time.Millisecond) time.Sleep(time.Duration(100*oscillationFactor()) * time.Millisecond)
} }
}() }()
go func() { go func() {
for { for {
rpcDurations.WithLabelValues("normal").Observe((rand.NormFloat64() * *normDomain) + *normMean) v := (rand.NormFloat64() * *normDomain) + *normMean
rpcDurations.WithLabelValues("normal").Observe(v)
rpcDurationsHistogram.Observe(v)
time.Sleep(time.Duration(75*oscillationFactor()) * time.Millisecond) time.Sleep(time.Duration(75*oscillationFactor()) * time.Millisecond)
} }
}() }()
go func() { go func() {
for { for {
rpcDurations.WithLabelValues("exponential").Observe(rand.ExpFloat64()) v := rand.ExpFloat64()
rpcDurations.WithLabelValues("exponential").Observe(v)
time.Sleep(time.Duration(50*oscillationFactor()) * time.Millisecond) time.Sleep(time.Duration(50*oscillationFactor()) * time.Millisecond)
} }
}() }()