Class: NewRelic::Agent::Tracer

Inherits:
Object
  • Object
show all
Defined in:
lib/new_relic/agent/tracer.rb

Overview

This class helps you interact with the current transaction (if it exists), start new transactions/segments, etc.

Defined Under Namespace

Classes: State

Constant Summary collapse

UNKNOWN = 
'Unknown'.freeze
OTHER = 
'other'.freeze

Class Method Summary collapse

Class Method Details

.accept_distributed_trace_payload(payload) ⇒ Object 



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# File 'lib/new_relic/agent/tracer.rb', line 196

def accept_distributed_trace_payload(payload)
  return unless txn = current_transaction

  txn.distributed_tracer.accept_distributed_trace_payload(payload)
end

.capture_segment_error(segment) ⇒ Object

Will potentially capture and notice an error at the segment that was executing when error occurred. if passed segment is something that doesn’t respond to notice_segment_error then this method is effectively just a yield to the given &block



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# File 'lib/new_relic/agent/tracer.rb', line 354

def capture_segment_error(segment)
  return unless block_given?

  yield
rescue => exception
  # needs else branch coverage
  segment.notice_error(exception) if segment&.is_a?(Transaction::AbstractSegment)
  raise
end

.clear_state ⇒ Object Also known as: tl_clear 



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# File 'lib/new_relic/agent/tracer.rb', line 407

def clear_state
  Thread.current[:newrelic_tracer_state] = nil
end

.create_distributed_trace_payload ⇒ Object 



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# File 'lib/new_relic/agent/tracer.rb', line 190

def create_distributed_trace_payload
  return unless txn = current_transaction

  txn.distributed_tracer.create_distributed_trace_payload
end

.current_segment ⇒ Object

Returns the currently active segment in the transaction in progress for this thread, or nil if no segment or transaction exists.



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# File 'lib/new_relic/agent/tracer.rb', line 207

def current_segment
  return unless txn = current_transaction

  txn.current_segment
end

.current_segment_key ⇒ Object 



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# File 'lib/new_relic/agent/tracer.rb', line 413

def current_segment_key
  ::Fiber.current.object_id
end

.current_span_id ⇒ Object Also known as: span_id

Returns the id of the current span, or nil if none exists.



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# File 'lib/new_relic/agent/tracer.rb', line 57

def current_span_id
  if span = current_segment
    span.guid
  end
end

.current_trace_id ⇒ Object Also known as: trace_id

Returns the trace_id of the current_transaction, or nil if none exists.



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# File 'lib/new_relic/agent/tracer.rb', line 47

def current_trace_id
  if txn = current_transaction
    txn.trace_id
  end
end

.current_transaction ⇒ Object

Returns the transaction in progress for this thread, or nil if none exists.



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# File 'lib/new_relic/agent/tracer.rb', line 39

def current_transaction
  state.current_transaction
end

.in_transaction(name: nil, partial_name: nil, category:, options: {}) ⇒ Object

Runs the given block of code in a transaction.

Parameters:

  • name (String) (defaults to: nil) —

    reserved for New Relic internal use

  • partial_name (String) (defaults to: nil) —

    a meaningful name for this transaction (e.g., blogs/index); the Ruby agent will add a New-Relic-specific prefix

  • category (Symbol) —

    :web for web transactions or :background for background transactions

  • options (Hash) (defaults to: {}) —

    reserved for New Relic internal use



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# File 'lib/new_relic/agent/tracer.rb', line 90

def in_transaction(name: nil,
  partial_name: nil,
  category:,
  options: {})

  finishable = start_transaction_or_segment(
    name: name,
    partial_name: partial_name,
    category: category,
    options: options
  )

  begin
    # We shouldn't raise from Tracer.start_transaction_or_segment, but
    # only wrap the yield to be absolutely sure we don't report agent
    # problems as app errors
    yield
  rescue => exception
    current_transaction.notice_error(exception)
    raise
  ensure
    finishable&.finish
  end
end

.start_datastore_segment(product: nil, operation: nil, collection: nil, host: nil, port_path_or_id: nil, database_name: nil, start_time: nil, parent: nil) ⇒ DatastoreSegment

Creates and starts a datastore segment used to time datastore operations.

Parameters:

  • product (String) (defaults to: nil) —

    the datastore name for use in metric naming, e.g. “FauxDB”

  • operation (String) (defaults to: nil) —

    the name of the operation (e.g. “select”), often named after the method that’s being instrumented.

  • collection (optional, String) (defaults to: nil) —

    the collection name for use in statement-level metrics (i.e. table or model name)

  • host (optional, String) (defaults to: nil) —

    the host this database instance is running on

  • port_path_or_id (optional, String) (defaults to: nil) —

    TCP port, file path, UNIX domain socket, or other connection-related info

  • database_name (optional, String) (defaults to: nil) —

    the name of this database

  • start_time (optional, Time) (defaults to: nil) —

    a Time instance denoting the start time of the segment. Value is set by AbstractSegment#start if not given.

  • parent (optional, Segment) (defaults to: nil) —

    Use for the rare cases (such as async) where the parent segment should be something other than the current segment

Returns:

  • (DatastoreSegment) —

    the newly created segment; you must call finish on it at the end of the code you’re tracing



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# File 'lib/new_relic/agent/tracer.rb', line 288

def start_datastore_segment(product: nil,
  operation: nil,
  collection: nil,
  host: nil,
  port_path_or_id: nil,
  database_name: nil,
  start_time: nil,
  parent: nil)

  product ||= UNKNOWN
  operation ||= OTHER

  segment = Transaction::DatastoreSegment.new(product, operation, collection, host, port_path_or_id, database_name)
  start_and_add_segment(segment, parent)
rescue ArgumentError
  raise
rescue => exception
  log_error('start_datastore_segment', exception)
end

.start_external_request_segment(library:, uri:, procedure:, start_time: nil, parent: nil) ⇒ ExternalRequestSegment

Creates and starts an external request segment using the given library, URI, and procedure. This is used to time external calls made over HTTP.

Parameters:

  • library (String) —

    a string of the class name of the library used to make the external call, for example, ‘Net::HTTP’.

  • uri (String, URI) —

    indicates the URI to which the external request is being made. The URI should begin with the protocol, for example, ‘github.com’.

  • procedure (String) —

    the HTTP method being used for the external request as a string, for example, ‘GET’.

  • start_time (optional, Time) (defaults to: nil) —

    a Time instance denoting the start time of the segment. Value is set by AbstractSegment#start if not given.

  • parent (optional, Segment) (defaults to: nil) —

    Use for the rare cases (such as async) where the parent segment should be something other than the current segment

Returns:

  • (ExternalRequestSegment) —

    the newly created segment; you must call finish on it at the end of the code you’re tracing



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# File 'lib/new_relic/agent/tracer.rb', line 335

def start_external_request_segment(library:,
  uri:,
  procedure:,
  start_time: nil,
  parent: nil)

  segment = Transaction::ExternalRequestSegment.new(library, uri, procedure, start_time)
  start_and_add_segment(segment, parent)
rescue ArgumentError
  raise
rescue => exception
  log_error('start_external_request_segment', exception)
end

.start_message_broker_segment(action:, library:, destination_type:, destination_name:, headers: nil, parameters: nil, start_time: nil, parent: nil) ⇒ Object

For New Relic internal use only.



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# File 'lib/new_relic/agent/tracer.rb', line 365

def start_message_broker_segment(action:,
  library:,
  destination_type:,
  destination_name:,
  headers: nil,
  parameters: nil,
  start_time: nil,
  parent: nil)

  segment = Transaction::MessageBrokerSegment.new(
    action: action,
    library: library,
    destination_type: destination_type,
    destination_name: destination_name,
    headers: headers,
    parameters: parameters,
    start_time: start_time
  )
  start_and_add_segment(segment, parent)
rescue ArgumentError
  raise
rescue => exception
  log_error('start_datastore_segment', exception)
end

.start_segment(name:, unscoped_metrics: nil, start_time: nil, parent: nil) ⇒ Segment

Creates and starts a general-purpose segment used to time arbitrary code.

Parameters:

  • name (String) —

    full name of the segment; the agent will not add a prefix. Third-party users should begin the name with Custom/; e.g., Custom/UserMailer/send_welcome_email

  • unscoped_metrics (optional, String, Array) (defaults to: nil) —

    additional unscoped metrics to record using this segment’s timing information

  • start_time (optional, Time) (defaults to: nil) —

    a Time instance denoting the start time of the segment. Value is set by AbstractSegment#start if not given.

  • parent (optional, Segment) (defaults to: nil) —

    Use for the rare cases (such as async) where the parent segment should be something other than the current segment

Returns:

  • (Segment) —

    the newly created segment; you must call finish on it at the end of the code you’re tracing



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# File 'lib/new_relic/agent/tracer.rb', line 237

def start_segment(name:,
  unscoped_metrics: nil,
  start_time: nil,
  parent: nil)

  segment = Transaction::Segment.new(name, unscoped_metrics, start_time)
  start_and_add_segment(segment, parent)
rescue ArgumentError
  raise
rescue => exception
  log_error('start_segment', exception)
end

.start_transaction(category:, name: nil, partial_name: nil, **options) ⇒ Object

Takes name or partial_name and a category. Returns a transaction instance or nil



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# File 'lib/new_relic/agent/tracer.rb', line 163

def start_transaction(category:,
  name: nil,
  partial_name: nil,
  **options)

  raise ArgumentError, 'missing required argument: name or partial_name' if name.nil? && partial_name.nil?

  return current_transaction if current_transaction

  if name
    options[:transaction_name] = name
  else
    options[:transaction_name] = Transaction.name_from_partial(
      partial_name,
      category
    )
  end

  Transaction.start_new_transaction(state,
    category,
    options)
rescue ArgumentError
  raise
rescue => exception
  log_error('start_transaction', exception)
end

.start_transaction_or_segment(name: nil, partial_name: nil, category:, options: {}) ⇒ Object, #finish

Starts a segment on the current transaction (if one exists) or starts a new transaction otherwise.

Parameters:

  • name (String) (defaults to: nil) —

    reserved for New Relic internal use

  • partial_name (String) (defaults to: nil) —

    a meaningful name for this transaction (e.g., blogs/index); the Ruby agent will add a New-Relic-specific prefix

  • category (Symbol) —

    :web for web transactions or :task for background transactions

  • options (Hash) (defaults to: {}) —

    reserved for New Relic internal use

Returns:

  • (Object, #finish) —

    an object that responds to finish; you must call finish on it at the end of the code you’re tracing



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# File 'lib/new_relic/agent/tracer.rb', line 134

def start_transaction_or_segment(name: nil,
  partial_name: nil,
  category:,
  options: {})

  raise ArgumentError, 'missing required argument: name or partial_name' if name.nil? && partial_name.nil?

  if name
    options[:transaction_name] = name
  else
    options[:transaction_name] = Transaction.name_from_partial(
      partial_name,
      category
    )
  end

  if (txn = current_transaction)
    txn.create_nested_segment(category, options)
  else
    Transaction.start_new_transaction(state, category, options)
  end
rescue ArgumentError
  raise
rescue => exception
  log_error('start_transaction_or_segment', exception)
end

.state ⇒ Object Also known as: tl_get 



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# File 'lib/new_relic/agent/tracer.rb', line 21

def state
  state_for(Thread.current)
end

.state_for(thread) ⇒ Object Also known as: tl_state_for

This method should only be used by Tracer for access to the current thread’s state or to provide read-only accessors for other threads

If ever exposed, this requires additional synchronization



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# File 'lib/new_relic/agent/tracer.rb', line 394

def state_for(thread)
  state = thread[:newrelic_tracer_state]

  if state.nil?
    state = Tracer::State.new
    thread[:newrelic_tracer_state] = state
  end

  state
end

.thread_block_with_current_transaction(segment_name: nil, parent: nil, &block) ⇒ Object 



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# File 'lib/new_relic/agent/tracer.rb', line 421

def thread_block_with_current_transaction(segment_name: nil, parent: nil, &block)
  parent ||= current_segment
  current_txn = ::Thread.current[:newrelic_tracer_state]&.current_transaction if ::Thread.current[:newrelic_tracer_state]&.is_execution_traced?
  proc do |*args|
    begin
      if current_txn && !current_txn.finished?
        NewRelic::Agent::Tracer.state.current_transaction = current_txn
        ::Thread.current[:newrelic_thread_span_parent] = parent
        current_txn.async = true
        segment_name = "#{segment_name}/Thread#{::Thread.current.object_id}/Fiber#{::Fiber.current.object_id}" if NewRelic::Agent.config[:'thread_ids_enabled']
        segment = NewRelic::Agent::Tracer.start_segment(name: segment_name, parent: parent) if segment_name
      end
      NewRelic::Agent::Tracer.capture_segment_error(segment) do
        yield(*args)
      end
    ensure
      ::NewRelic::Agent::Transaction::Segment.finish(segment)
    end
  end
end

.thread_tracing_enabled? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/tracer.rb', line 417

def thread_tracing_enabled?
  NewRelic::Agent.config[:'instrumentation.thread.tracing']
end

.tracing_enabled? ⇒ Boolean

Returns true unless called from within an NewRelic::Agent.disable_all_tracing block.

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/tracer.rb', line 31

def tracing_enabled?
  state.tracing_enabled?
end

.transaction_sampled? ⇒ Boolean Also known as: sampled?

Returns a boolean indicating whether the current_transaction is sampled, or nil if there is no current transaction.

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/tracer.rb', line 68

def transaction_sampled?
  txn = current_transaction
  return false unless txn

  txn.sampled?
end