Best way to selectively prevent span recording?

[treyhyde]

I'd like to cut down on the noise and data volume somewhat by excluding certain controller from tracing. I looked through the rack instrumentation and threw in

 OpenTelemetry::SDK.configure do |c|
    OpenTelemetry::Instrumentation::Rack::Instrumentation.instance.config['untraced_endpoints'] = [
      'probes/ready'
    ]
 ...

to no effect. Any best practices or suggestions for this case? Thanks

[ericmustin]

@treyhyde That should do the trick, what's the rack env['PATH_INFO'] for that endpoint? It would have to match that exactly

opentelemetry-ruby/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/tracer_middleware.rb

Line 89 in 02fa36b

@untraced_endpoints.include?(env['PATH_INFO'])

.

[fbogsany]

OpenTelemetry::SDK.configure do |c|
  c.use 'OpenTelemetry::Instrumentation::Rack', { untraced_endpoints: ['probes/ready'] }
end

or

OpenTelemetry::SDK.configure do |c|
  c.use_all { 'OpenTelemetry::Instrumentation::Rack' => { untraced_endpoints: ['probes/ready'] } }
end

Two things here:

1. c.use or c.use_all should be used to set config options for instrumentation rather than setting it directly with OpenTelemetry::Instrumentation::Rack::Instrumentation.instance.config - the latter will either not install the instrumentation correctly or will clobber its config.
2. Config option names are symbols rather than strings.

[treyhyde]

thank you!