60 lines
2.8 KiB
Go
60 lines
2.8 KiB
Go
// Package metrics provides a framework for application instrumentation. All
|
|
// metrics are safe for concurrent use. Considerable design influence has been
|
|
// taken from https://github.com/codahale/metrics and https://prometheus.io.
|
|
//
|
|
// This package contains the common interfaces. Your code should take these
|
|
// interfaces as parameters. Implementations are provided for different
|
|
// instrumentation systems in the various subdirectories.
|
|
//
|
|
// Usage
|
|
//
|
|
// Metrics are dependencies and should be passed to the components that need
|
|
// them in the same way you'd construct and pass a database handle, or reference
|
|
// to another component. So, create metrics in your func main, using whichever
|
|
// concrete implementation is appropriate for your organization.
|
|
//
|
|
// latency := prometheus.NewSummaryFrom(stdprometheus.SummaryOpts{
|
|
// Namespace: "myteam",
|
|
// Subsystem: "foosvc",
|
|
// Name: "request_latency_seconds",
|
|
// Help: "Incoming request latency in seconds."
|
|
// }, []string{"method", "status_code"})
|
|
//
|
|
// Write your components to take the metrics they will use as parameters to
|
|
// their constructors. Use the interface types, not the concrete types. That is,
|
|
//
|
|
// // NewAPI takes metrics.Histogram, not *prometheus.Summary
|
|
// func NewAPI(s Store, logger log.Logger, latency metrics.Histogram) *API {
|
|
// // ...
|
|
// }
|
|
//
|
|
// func (a *API) ServeFoo(w http.ResponseWriter, r *http.Request) {
|
|
// begin := time.Now()
|
|
// // ...
|
|
// a.latency.Observe(time.Since(begin).Seconds())
|
|
// }
|
|
//
|
|
// Finally, pass the metrics as dependencies when building your object graph.
|
|
// This should happen in func main, not in the global scope.
|
|
//
|
|
// api := NewAPI(store, logger, latency)
|
|
// http.ListenAndServe("/", api)
|
|
//
|
|
// Implementation details
|
|
//
|
|
// Each telemetry system has different semantics for label values, push vs.
|
|
// pull, support for histograms, etc. These properties influence the design of
|
|
// their respective packages. This table attempts to summarize the key points of
|
|
// distinction.
|
|
//
|
|
// SYSTEM DIM COUNTERS GAUGES HISTOGRAMS
|
|
// dogstatsd n batch, push-aggregate batch, push-aggregate native, batch, push-each
|
|
// statsd 1 batch, push-aggregate batch, push-aggregate native, batch, push-each
|
|
// graphite 1 batch, push-aggregate batch, push-aggregate synthetic, batch, push-aggregate
|
|
// expvar 1 atomic atomic synthetic, batch, in-place expose
|
|
// influx n custom custom custom
|
|
// prometheus n native native native
|
|
// circonus 1 native native native
|
|
// pcp 1 native native native
|
|
//
|
|
package metrics
|