Class: Tracelit::ErrorAlwaysOnSampler

Inherits:
Object
  • Object
show all
Defined in:
lib/tracelit/error_always_on_sampler.rb

Overview

ErrorAlwaysOnSampler wraps a ratio-based sampler but upgrades DROP decisions to RECORD_ONLY. This ensures span processors (including ErrorSpanProcessor) fire on_end for ALL spans, even those outside the sampling ratio.

Without this, TraceIdRatioBased(0.0) returns DROP, which causes the SDK to create NonRecordingSpans that bypass the processor pipeline entirely — so ErrorSpanProcessor.on_end is never called.

With RECORD_ONLY:

  • Real spans are created and all processors fire

  • BatchSpanProcessor ignores them (checks trace_flags.sampled? == false)

  • ErrorSpanProcessor sees them and exports any that end in ERROR

Constant Summary collapse

Decision = 
OpenTelemetry::SDK::Trace::Samplers::Decision
Result = 
OpenTelemetry::SDK::Trace::Samplers::Result

Instance Method Summary collapse

Constructor Details

#initialize(rate) ⇒ ErrorAlwaysOnSampler

Returns a new instance of ErrorAlwaysOnSampler.



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# File 'lib/tracelit/error_always_on_sampler.rb', line 21

def initialize(rate)
  @inner = OpenTelemetry::SDK::Trace::Samplers.trace_id_ratio_based(rate)
end

Instance Method Details

#description ⇒ Object 



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# File 'lib/tracelit/error_always_on_sampler.rb', line 43

def description
  "ErrorAlwaysOnSampler{#{@inner.description}}"
end

#should_sample?(trace_id:, parent_context:, links:, name:, kind:, attributes:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tracelit/error_always_on_sampler.rb', line 25

def should_sample?(trace_id:, parent_context:, links:, name:, kind:, attributes:)
  result = @inner.should_sample?(
    trace_id: trace_id,
    parent_context: parent_context,
    links: links,
    name: name,
    kind: kind,
    attributes: attributes
  )

  if result.recording?
    result
  else
    # Upgrade DROP → RECORD_ONLY so processor pipeline fires
    Result.new(decision: Decision::RECORD_ONLY, tracestate: result.tracestate)
  end
end