tracer.start_span() not working with_parent

[ToolKami]

I'm able to get a trace exported with the following:

single_span = @tracer.start_span("single")
puts single_span #<OpenTelemetry::SDK::Trace::Span:0x0000ffff9894ac30>
puts single_span.context #<OpenTelemetry::Trace::SpanContext:0x0000ffff9894aca8>
puts "single span trace id: #{single_span.context.hex_trace_id}" #single span trace id: 821fcac9cfc6299c453547828ab9f697
single_span.finish

It doesn't show any error but no traces got exported with the following:

  new_span_context = OpenTelemetry::Trace::SpanContext.new(
      trace_id: ["42020f5b57b799cd98bc793ac046fad8"].pack("H*"),
  )
  puts "new context valid: #{new_span_context.valid?}" # true
  new_span = OpenTelemetry::Trace::Span.new(span_context: new_span_context)
  context_with_remote_parent = OpenTelemetry::Trace.context_with_span(new_span)

  parent_span = @tracer.start_span("parent", with_parent: context_with_remote_parent)
  puts parent_span #<OpenTelemetry::Trace::Span:0x0000ffff9894b400>
  puts parent_span.context #<OpenTelemetry::Trace::SpanContext:0x0000ffff9894b478>
  puts "parent span trace id: #{parent_span.context.hex_trace_id}" #parent span trace id: 42020f5b57b799cd98bc793ac046fad8
  parent_span.finish

I've spent a few days reading through the code and experimenting, any help is greatly appreciated, thanks!

[arielvalentin]

@ToolKami I believe this is more appropriate to be a discussion since I do not think this is a bug.

[arielvalentin]

@ToolKami Based on the code snippets it does not look like you are setting a parent span ID or the Sampling flag.

Without a parent span id you will not be able to properly link the child span and the sampling flag is "off" by default:

https://github.com/open-telemetry/opentelemetry-ruby/blob/main/api/lib/opentelemetry/trace/span_context.rb#L27

[ToolKami]

@arielvalentin turning on the Sampling flag did the trick - gosh I spent 2 days and missed this behaviour -_- Thanks a lot for the help!!