How do you turn off the OpenTelementry INFO messages in Rails startup?

[rnhurt]

When we turned on OpenTelemetry in our Rails 6/7 apps we started getting a bunch of INFO messages dumped to stdout. Nothing else in our Rails apps generates these types of messages and I can't seem to find a way to turn them off. They don't seem to obey the Rails.logger config settings.

Is anyone else having this problem or is it just me? Am I missing some config somewhere that disables these INFO messages? Or is this a bug in OpenTelementry?

...
I, [2024-09-13] INFO -- : Instrumentation: OpenTelemetry::Instrumentation::ActiveSupport was successfully ...
I, [2024-09-13] INFO -- : Instrumentation: OpenTelemetry::Instrumentation::Rack was successfully ...
I, [2024-09-13] INFO -- : Instrumentation: OpenTelemetry::Instrumentation::ActionPack was successfully ...
I, [2024-09-13] INFO -- : Instrumentation: OpenTelemetry::Instrumentation::ActiveJob was successfully ...
I, [2024-09-13] INFO -- : Instrumentation: OpenTelemetry::Instrumentation::ActiveRecord was successfully ...
I, [2024-09-13] INFO -- : Instrumentation: OpenTelemetry::Instrumentation::ActionView was successfully ...
I, [2024-09-13] INFO -- : Instrumentation: OpenTelemetry::Instrumentation::ActionMailer was successfully ...
I, [2024-09-13] INFO -- : Instrumentation: OpenTelemetry::Instrumentation::HTTP was successfully ...
I, [2024-09-13] INFO -- : Instrumentation: OpenTelemetry::Instrumentation::ActiveModelSerializers was successfully ...
I, [2024-09-13] INFO -- : Instrumentation: OpenTelemetry::Instrumentation::ConcurrentRuby was successfully ...
...

[arielvalentin]

The most consistent way to control log verbosity for the OTel SDK is to use the OTEL_LOG_LEVEL environment variable, which is set to INFO by default¹.

You may also provide your own logger to the SDK Configurator during initialization².

E.g.

OpenTelemetry::SDK.configure do |c|
  c.logger = rails_configuration.logger  
  # custom configuration
end

In this case the OTel logger will wrap your custom logger and send it messages at info level, unless you set the envar.

From there your logger will receive info or higher.

Footnotes

1. https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/#general-sdk-configuration ↩

2. https://www.rubydoc.info/gems/opentelemetry-sdk/OpenTelemetry/SDK/Configurator#logger=-instance_method ↩

[rnhurt]

Yes, that seems to work.

Thanx! 🎉

[robbkidd]

In the near future, the OTel SDK will provide the capability to export logs from the Rails logger as OpenTelemetry data. At that point, you might consider not using the same logger instances for the OTel SDK as for the rest of your application. The OTel SDK's log output is where errors around sending data will appear … and if the OTel SDK is having trouble sending data, the logs telling you about that trouble will be among the data not being sent.