How to use pprof extension for profiling

[mmynk]

Component(s)

extension/pprof

Describe the issue you're reporting

I am trying to use the pprof extension in an OpenTelemetry collector.

I have added the following to my config otelcol.yaml:

extensions:
  pprof:
  pprof/1:
    endpoint: "127.0.0.1:1777"
    block_profile_fraction: 3
    mutex_profile_fraction: 5
    save_to_file: "cpu.pprof"

However, I am not seeing anything at that endpoint. Also the following command errors out:

$ go tool pprof http://localhost:1777/debug/pprof/profile\?seconds\=30

Fetching profile over HTTP from http://localhost:1777/debug/pprof/profile?seconds=30
http://localhost:1777/debug/pprof/profile?seconds=30: Get "http://localhost:1777/debug/pprof/profile?seconds=30": dial tcp 127.0.0.1:1777: connect: connection refused
failed to fetch any source profiles

I am sure I am missing something but being inexperienced with using profilers, I am not sure what. Do I need to ListenAndServe manually? Would appreciate any guidance.

[github-actions]

Pinging code owners:

• extension/pprof: @MovieStoreGuy

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[mmynk]

/label help-wanted @MovieStoreGuy

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

Pinging code owners:

• extension/pprof: @MovieStoreGuy

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[honeychaudharyc]

Hi @mmynk,
Can you try below configuration in your otelcol.yaml file-

receivers:
  otlp:
    protocols:
      http:
      grpc:

processors:
  batch:
    send_batch_max_size: 100
    send_batch_size: 10
    timeout: 10s

extensions:
  pprof:
    endpoint: localhost:1777

exporters:
  debug:
     verbosity: detailed 
    
service:
  extensions: [pprof]
  pipelines:
    traces:
      receivers: [otlp]
      processors: [batch]
      exporters: [debug]

I used this and it works-

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

Pinging code owners:

• extension/pprof: @MovieStoreGuy

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[mmynk]

I had missed adding:
extension: [pprof] to service.

Thank you, @honeychaudharyc.