Class: Datadog::Tracing::TraceOperation

Inherits:
Object
  • Object
show all
Includes:
OpenTelemetry::API::TraceOperation, Metadata::Tagging
Defined in:
lib/datadog/tracing/trace_operation.rb

Overview

Represents the act of tracing a series of operations, by generating and collecting span measurements. When completed, it yields a trace.

Supports synchronous code flow only. Usage across multiple threads will result in incorrect relationships. For async support, a TraceOperation should be employed per execution context (e.g. Thread, etc.)

Defined Under Namespace

Classes: Events

Constant Summary collapse

DEFAULT_MAX_LENGTH = 
100_000
AUTO_SAMPLING_PRIORITIES = 
[Sampling::Ext::Priority::AUTO_KEEP, Sampling::Ext::Priority::AUTO_REJECT].freeze
RECONSIDERABLE_DECISIONS = 
[Sampling::Ext::Decision::DEFAULT, Sampling::Ext::Decision::AGENT_RATE].freeze

Constants included from Metadata::Tagging

Metadata::Tagging::ENSURE_AGENT_TAGS, Metadata::Tagging::NUMERIC_TAG_SIZE_RANGE

Instance Attribute Summary collapse

Attributes included from OpenTelemetry::API::TraceOperation

#otel_context

Instance Method Summary collapse

Methods included from OpenTelemetry::API::TraceOperation

#otel_value, #otel_values

Methods included from Metadata::Tagging

#clear_metric, #clear_tag, #has_tag?, #set_metric, #set_tag, #set_tags

Constructor Details

#initialize(logger: Datadog.logger, agent_sample_rate: nil, events: nil, hostname: nil, id: nil, max_length: DEFAULT_MAX_LENGTH, name: nil, origin: nil, parent_span_id: nil, span_links: nil, rate_limiter_rate: nil, resource: nil, rule_sample_rate: nil, sample_rate: nil, sampled: nil, sampling_priority: nil, service: nil, profiling_enabled: nil, apm_tracing_enabled: nil, tags: nil, metrics: nil, trace_state: nil, remote_parent: false, distributed_sampling_priority: false, tracer: nil, baggage: nil, auto_finish: true) ⇒ TraceOperation

Creates a new TraceOperation.

Parameters:



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# File 'lib/datadog/tracing/trace_operation.rb', line 66

def initialize(
  logger: Datadog.logger,
  agent_sample_rate: nil,
  events: nil,
  hostname: nil,
  id: nil,
  max_length: DEFAULT_MAX_LENGTH,
  name: nil,
  origin: nil,
  parent_span_id: nil,
  span_links: nil,
  rate_limiter_rate: nil,
  resource: nil,
  rule_sample_rate: nil,
  sample_rate: nil,
  sampled: nil,
  sampling_priority: nil,
  service: nil,
  profiling_enabled: nil,
  apm_tracing_enabled: nil,
  tags: nil,
  metrics: nil,
  trace_state: nil,
  remote_parent: false,
  distributed_sampling_priority: false,
  tracer: nil, # DEV-3.0: deprecated, remove in 3.0
  baggage: nil,
  auto_finish: true
)
  @logger = logger

  # Attributes
  @id = id || Tracing::Utils::TraceId.next_id
  @max_length = max_length || DEFAULT_MAX_LENGTH
  @parent_span_id = parent_span_id
  @sampled = sampled.nil? || sampled
  @remote_parent = remote_parent
  @distributed_sampling_priority = distributed_sampling_priority
  @span_links = span_links
  # Tags
  @agent_sample_rate = agent_sample_rate
  @hostname = hostname
  @name = name
  @origin = origin
  @rate_limiter_rate = rate_limiter_rate
  @resource = resource
  @rule_sample_rate = rule_sample_rate
  @sample_rate = sample_rate
  @sampling_priority = sampling_priority
  @service = service
  @profiling_enabled = profiling_enabled
  @apm_tracing_enabled = apm_tracing_enabled
  @trace_state = trace_state || Distributed::TraceState.new
  @baggage = baggage

  # Generic tags
  set_tags(tags) if tags
  set_tags(metrics) if metrics

  # State
  @root_span = nil
  @active_span = nil
  @active_span_count = 0
  @events = events || Events.new
  @finished = false
  @spans = []
  @auto_finish = !!auto_finish
  @flushed = false
  @propagated = false
end

Instance Attribute Details

#active_span ⇒ Object (readonly)

Returns the value of attribute active_span.



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# File 'lib/datadog/tracing/trace_operation.rb', line 45

def active_span
  @active_span
end

#active_span_count ⇒ Object (readonly)

Returns the value of attribute active_span_count.



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# File 'lib/datadog/tracing/trace_operation.rb', line 45

def active_span_count
  @active_span_count
end

#agent_sample_rate ⇒ Object

Returns the value of attribute agent_sample_rate.



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# File 'lib/datadog/tracing/trace_operation.rb', line 34

def agent_sample_rate
  @agent_sample_rate
end

#baggage ⇒ Object

Returns the value of attribute baggage.



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# File 'lib/datadog/tracing/trace_operation.rb', line 34

def baggage
  @baggage
end

#hostname ⇒ Object

Returns the value of attribute hostname.



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# File 'lib/datadog/tracing/trace_operation.rb', line 34

def hostname
  @hostname
end

#id ⇒ Object (readonly)

Returns the value of attribute id.



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# File 'lib/datadog/tracing/trace_operation.rb', line 45

def id
  @id
end

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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# File 'lib/datadog/tracing/trace_operation.rb', line 45

def logger
  @logger
end

#max_length ⇒ Object (readonly)

Returns the value of attribute max_length.



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# File 'lib/datadog/tracing/trace_operation.rb', line 45

def max_length
  @max_length
end

#name ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 189

def name
  @name || root_span&.name
end

#origin ⇒ Object

Returns the value of attribute origin.



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# File 'lib/datadog/tracing/trace_operation.rb', line 34

def origin
  @origin
end

#parent_span_id ⇒ Object (readonly)

Returns the value of attribute parent_span_id.



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# File 'lib/datadog/tracing/trace_operation.rb', line 45

def parent_span_id
  @parent_span_id
end

#rate_limiter_rate ⇒ Object

Returns the value of attribute rate_limiter_rate.



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# File 'lib/datadog/tracing/trace_operation.rb', line 34

def rate_limiter_rate
  @rate_limiter_rate
end

#remote_parent ⇒ Object

Returns the value of attribute remote_parent.



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# File 'lib/datadog/tracing/trace_operation.rb', line 34

def remote_parent
  @remote_parent
end

#rule_sample_rate ⇒ Object

Returns the value of attribute rule_sample_rate.



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# File 'lib/datadog/tracing/trace_operation.rb', line 34

def rule_sample_rate
  @rule_sample_rate
end

#sample_rate ⇒ Object

Returns the value of attribute sample_rate.



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# File 'lib/datadog/tracing/trace_operation.rb', line 34

def sample_rate
  @sample_rate
end

#sampled=(value) ⇒ Object (writeonly)

Sets the attribute sampled

Parameters:

  • value —

    the value to set the attribute sampled to.



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# File 'lib/datadog/tracing/trace_operation.rb', line 54

def sampled=(value)
  @sampled = value
end

#sampling_priority ⇒ Object

Returns the value of attribute sampling_priority.



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# File 'lib/datadog/tracing/trace_operation.rb', line 34

def sampling_priority
  @sampling_priority
end

#service ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 233

def service
  @service || root_span&.service
end

#trace_state ⇒ Object (readonly)

Returns the value of attribute trace_state.



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# File 'lib/datadog/tracing/trace_operation.rb', line 45

def trace_state
  @trace_state
end

Instance Method Details

#build_span(op_name, logger: Datadog.logger, events: nil, on_error: nil, resource: nil, service: nil, start_time: nil, tags: nil, type: nil, id: nil) ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 276

def build_span(
  op_name,
  logger: Datadog.logger,
  events: nil,
  on_error: nil,
  resource: nil,
  service: nil,
  start_time: nil,
  tags: nil,
  type: nil,
  id: nil
)
  # Resolve span options:
  # Parent, service name, etc.
  # Add default options
  trace_id = @id
  parent = @active_span

  # Use active span's span ID if available. Otherwise, the parent span ID.
  # Necessary when this trace continues from another, e.g. distributed trace.
  parent_id = parent ? parent.id : @parent_span_id || 0

  # Build events
  span_events = events || SpanOperation::Events.new(logger: logger)

  # Before start: activate the span, publish events.
  span_events.before_start.subscribe do |span_op|
    start_span(span_op)
  end

  # Before finish: allow enrichment before the span is finalized, publish events.
  span_events.before_finish.subscribe do |span_op|
    before_finish_span(span_op)
  end

  # After finish: deactivate the span, record, publish events.
  span_events.after_finish.subscribe do |span, span_op|
    finish_span(span, span_op, parent)
  end

  # Build a new span operation
  SpanOperation.new(
    op_name,
    logger: logger,
    events: span_events,
    on_error: on_error,
    parent_id: parent_id,
    links: (@root_span.nil? ? @span_links : nil),
    resource: resource || op_name,
    service: service,
    start_time: start_time,
    tags: tags,
    trace_id: trace_id,
    type: type,
    id: id
  )
rescue => e
  logger.debug { "Failed to build new span: #{e.class}: #{e.message}" }

  # Return dummy span
  SpanOperation.new(op_name, logger: logger)
end

#finished? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/datadog/tracing/trace_operation.rb', line 145

def finished?
  @finished == true
end

#finished_span_count ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 141

def finished_span_count
  @spans.length
end

#flush! {|spans| ... } ⇒ TraceSegment

Returns a Datadog::Tracing::TraceSegment with all finished spans that can be flushed at invocation time. All other finished spans are discarded.

Yields:

  • (spans) —

    spans that will be returned as part of the trace segment returned

Returns:



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# File 'lib/datadog/tracing/trace_operation.rb', line 344

def flush!
  finished = finished?

  # Copy out completed spans
  spans = @spans.dup
  @spans = []
  @flushed = true

  spans = yield(spans) if block_given?

  # Use them to build a trace
  build_trace(spans, !finished)
end

#fork_clone ⇒ Object

Returns a copy of this trace suitable for forks (w/o spans.) Used for continuation of traces across forks.



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# File 'lib/datadog/tracing/trace_operation.rb', line 442

def fork_clone
  self.class.new(
    agent_sample_rate: @agent_sample_rate,
    events: @events&.dup,
    hostname: @hostname&.dup,
    id: @id,
    max_length: @max_length,
    name: name&.dup,
    origin: @origin&.dup,
    parent_span_id: @active_span&.id || @parent_span_id,
    rate_limiter_rate: @rate_limiter_rate,
    resource: resource&.dup,
    rule_sample_rate: @rule_sample_rate,
    sample_rate: @sample_rate,
    sampled: @sampled,
    sampling_priority: @sampling_priority,
    service: service&.dup,
    trace_state: @trace_state,
    tags: meta.dup,
    metrics: metrics.dup,
    remote_parent: @remote_parent,
    distributed_sampling_priority: @distributed_sampling_priority
  )
end

#full? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/datadog/tracing/trace_operation.rb', line 137

def full?
  @max_length > 0 && @active_span_count >= @max_length
end

#get_metric(key) ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 202

def get_metric(key)
  super || root_span&.get_metric(key)
end

#get_tag(key) ⇒ Object

When retrieving tags or metrics we need to include root span tags for sampling purposes



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# File 'lib/datadog/tracing/trace_operation.rb', line 198

def get_tag(key)
  super || root_span&.get_tag(key)
end

#keep! ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 167

def keep!
  self.sampling_priority = Sampling::Ext::Priority::USER_KEEP
  set_tag(Tracing::Metadata::Ext::Distributed::TAG_DECISION_MAKER, Tracing::Sampling::Ext::Decision::MANUAL)
  self.sampled = true # Just in case the in-app sampler had decided to drop this span, we revert that decision.
end

#measure(op_name, logger: Datadog.logger, events: nil, on_error: nil, resource: nil, service: nil, start_time: nil, tags: nil, type: nil, id: nil, &block) ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 237

def measure(
  op_name,
  logger: Datadog.logger,
  events: nil,
  on_error: nil,
  resource: nil,
  service: nil,
  start_time: nil,
  tags: nil,
  type: nil,
  id: nil,
  &block
)
  # Don't allow more span measurements if the
  # trace is already completed. Prevents multiple
  # root spans with parent_span_id = 0.
  if finished? || full?
    return yield(
      SpanOperation.new(op_name, logger: logger),
      TraceOperation.new(logger: logger))
  end

  # Create new span
  span_op = build_span(
    op_name,
    events: events,
    on_error: on_error,
    resource: resource,
    service: service,
    start_time: start_time,
    tags: tags,
    type: type,
    id: id
  )

  # Start span measurement
  span_op.measure { |s| yield(s, self) }
end

#priority_sampled? ⇒ Boolean

Has the priority sampling chosen to keep this span?

Returns:

  • (Boolean) 


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# File 'lib/datadog/tracing/trace_operation.rb', line 163

def priority_sampled?
  !@sampling_priority.nil? && @sampling_priority > 0
end

#reconsider_resource_sample? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/datadog/tracing/trace_operation.rb', line 227

def reconsider_resource_sample?
  return false if @resource.nil?

  reconsider_rule_sample?
end

#reject! ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 173

def reject!
  self.sampling_priority = Sampling::Ext::Priority::USER_REJECT
  set_tag(Tracing::Metadata::Ext::Distributed::TAG_DECISION_MAKER, Tracing::Sampling::Ext::Decision::MANUAL)
end

#resource ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 193

def resource
  @resource || root_span&.resource
end

#resource=(value) ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 178

def resource=(value)
  previous_resource = @resource
  @resource = value

  return if !!previous_resource || value.nil?

  events.trace_resource_change.publish(self)
rescue => e
  logger.debug { "Error updating trace resource: #{e.class}: #{e.message} Backtrace: #{e.backtrace.first(3)}" }
end

#resource_override? ⇒ Boolean

Returns true if the resource has been explicitly set

Returns:

  • (Boolean) 


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# File 'lib/datadog/tracing/trace_operation.rb', line 223

def resource_override?
  !@resource.nil?
end

#sampled? ⇒ Boolean

Will this trace be flushed by the tracer transport? This includes cases where the span is kept solely due to priority sampling.

This is not the ultimate Datadog App sampling decision. Downstream systems can decide to reject this trace, especially for cases where priority sampling is set to AUTO_KEEP.

Returns:

  • (Boolean) 


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# File 'lib/datadog/tracing/trace_operation.rb', line 157

def sampled?
  @sampled == true || priority_sampled?
end

#set_distributed_source(product_bit) ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 206

def set_distributed_source(product_bit)
  source = get_tag(Metadata::Ext::Distributed::TAG_TRACE_SOURCE)&.to_i(16) || 0
  source |= product_bit
  set_tag(Metadata::Ext::Distributed::TAG_TRACE_SOURCE, format("%02X", source))
end

#tags ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 212

def tags
  all_tags = {}
  all_tags.merge!(root_span&.tags || {}) if root_span
  all_tags.merge!(super)

  all_tags
end

#to_correlation ⇒ Object 



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# File 'lib/datadog/tracing/trace_operation.rb', line 429

def to_correlation
  # Resolve current span ID
  span_id = @active_span&.id
  span_id ||= @parent_span_id unless finished?

  Correlation::Identifier.new(
    trace_id: @id,
    span_id: span_id
  )
end

#to_digest ⇒ Object

Returns a set of trace headers used for continuing traces. Used for propagation across execution contexts. Data should reflect the active state of the trace. DEV-3.0: Sampling is a side effect of generating the digest. We should move the sample call to inject and right before moving to new contexts(threads, forking etc.)



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# File 'lib/datadog/tracing/trace_operation.rb', line 386

def to_digest
  # Resolve current span ID
  span_id = @active_span&.id
  span_id ||= @parent_span_id unless finished?
  # sample the trace_operation with the tracer
  @propagated = true
  events.trace_propagated.publish(self)

  open_telemetry = @trace_state.open_telemetry.outbound(
    trace_id: @id,
    sampling_priority: @sampling_priority,
    decision_maker: get_tag(Tracing::Metadata::Ext::Distributed::TAG_DECISION_MAKER),
    applied_rate: @rule_sample_rate || @agent_sample_rate,
    rate_limiter_rate: @rate_limiter_rate,
    distributed_sampling_priority: @distributed_sampling_priority,
  )

  TraceDigest.new(
    span_id: span_id,
    span_name: @active_span && @active_span.name,
    span_resource: @active_span && @active_span.resource,
    span_service: @active_span && @active_span.service,
    span_type: @active_span && @active_span.type,
    trace_distributed_tags: distributed_tags,
    trace_hostname: @hostname,
    trace_id: @id,
    trace_name: name,
    trace_origin: @origin,
    trace_process_id: Core::Environment::Identity.pid,
    trace_resource: resource,
    trace_runtime_id: Core::Environment::Identity.id,
    trace_sampling_priority: @sampling_priority,
    trace_service: service,
    trace_state: @trace_state.unknown_vendors,
    trace_state_unknown_fields: @trace_state.datadog.unknown_fields,
    trace_otel_random_value: open_telemetry.random_value,
    trace_otel_threshold: open_telemetry.threshold,
    trace_otel_unknown_fields: open_telemetry.unknown_fields,
    span_remote: @remote_parent && @active_span.nil?,
    baggage: (@baggage.nil? || @baggage.empty?) ? nil : @baggage
  ).freeze
end