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In March 2023, Grafana Labs acquired Pyroscope, the company behind the eponymous open source continuous profiling project. In September 2023, Grafana Pyroscope v1.0.0 was released.

This documentation covers Pyroscope versions preceding v1.0.0. We're keeping it for the time being, but we recommend that you upgrade to Grafana Pyroscope v1.0.0 or higher and switch to the new Grafana Pyroscope Docs for most up-to-date documentation.

Go Tracing Integration

note

This feature is currently undergoing a rewrite and will be updated as soon as we have re-enabled it. For any questions or updates feel free to reach out on github or slack!

OpenTelemetry support#

Pyroscope can integrate with distributed tracing systems supporting OpenTelemetry standard which allows you to link traces with the profiling data, and find specific lines of code related to a performance issue.

note
  • Only CPU profiling is supported at the moment.
  • We recommend you using Go 1.18 to ensure accurate results.
  • Because of how sampling profilers work, spans shorter than the sample interval may not be captured. Go CPU profiler probes stack traces 100 times per second, meaning that spans shorter than 10ms may not be captured.

Go code can be easily instrumented with otel-profiling-go package - a TracerProvider implementation, that annotates profiling data with span IDs which makes it possible to filter out profile of a particular trace span in Pyroscope:

# Make sure you also upgrade pyroscope server to version 0.14.0 or higher.go get github.com/pyroscope-io/otel-profiling-go

Now we can create and configure the tracer provider:

import otelpyroscope "github.com/pyroscope-io/otel-profiling-go"
// Create an exporter that prints traces to stdout.exporter, _ := stdouttrace.New(stdouttrace.WithPrettyPrint())tp := trace.NewTracerProvider(    trace.WithSampler(trace.AlwaysSample()),    trace.WithBatcher(exporter),)defer func() {    if err := tp.Shutdown(context.Background()); err != nil {        log.Fatal(err)    }}()
// We wrap the tracer provider to also annotate goroutines with Span ID so// that pprof would add corresponding labels to profiling samples.otel.SetTracerProvider(otelpyroscope.NewTracerProvider(tp,    otelpyroscope.WithAppName("simple.golang.app"),    otelpyroscope.WithPyroscopeURL("http://pyroscope-server:4040"),    otelpyroscope.WithRootSpanOnly(true),    otelpyroscope.WithAddSpanName(true),    otelpyroscope.WithProfileURL(true),    otelpyroscope.WithProfileBaselineURL(true),))

Please notice the WithRootSpanOnly option: when enabled, the tracer will annotate only the first span created locally (the root span), but the profile will include samples of all the nested spans. This may be helpful in case if the trace consists of multiple spans shorter than 10ms and profiler can't collect and annotate samples properly.

Another option that you may find useful is WithAddSpanName that controls whether the span name added to profile labels automatically. You can find description of all the options in the package documentation.

important

If you enable WithAddSpanName option, please make sure span names do not contain unique values, for example, a URL. Otherwise, this can increase data cardinality and slow down queries.

Now that we set up the tracer, we can create a new trace from anywhere:

ctx, span := otel.Tracer("tracerName").Start(context.Background(), "ExampleSpan")defer span.End()
// Your code goes here.

Collected profiles can be viewed in Pyroscope UI using FlameQL:

  • simple.golang.app.cpu{profile_id="<spanID>"} - Shows flamegraph for a particular span.
  • simple.golang.app.cpu{span_name="ExampleSpan"} - Shows aggregated profile for all spans named ExampleSpan.

For convenience, the tracer annotates profiled spans with extra attributes:

  • pyroscope.profile.id - is set to span ID to indicate that profile was captured for a span.
  • pyroscope.profile.url - contains the URL to the flamegraph in Pyroscope UI.
  • pyroscope.profile.baseline.url - contains the URL to the baseline comparison view in Pyroscope UI.

Baseline profiles#

A baseline profile is an aggregate of all span profiles. For example, consider two exemplars (the number here replaces profiling data):

  • app.cpu{region="us=east",env="dev",span_name="FetchData",profile_id="abc"} 100
  • app.cpu{region="us=east",env="dev",span_name="FetchData",profile_id="zyx"} 200

Then, the baseline profile for each of them is:

  • app.cpu{region="us=east",env="dev",span_name="FetchData"} 300

Examples#

Check out the examples directory in our repository to find a complete example application that demonstrates tracing integration features (using a custom jaeger ui) and learn more!

golang example

Using tracing exemplars manually#

If you're not using open telemetry integration you can still use exemplars storage to store profiles associated with some execution context (e.g individual HTTP / GRPC request). To create exemplars you need to tag specific parts of your code with a special profile_id tag, for example, in golang you could do this:

pprof.Do(ctx, pprof.Labels("profile_id", "8474e98b95013e4f"), func(ctx context.Context) {  slowRequest()})

"8474e98b95013e4f" can be any ID that you use to identify execution contexts (individual HTTP / GRPC requests).