Module: OpenTelemetry::Instrumentation::ActiveJob::Handlers

Defined in:
lib/opentelemetry/instrumentation/active_job/handlers.rb,
lib/opentelemetry/instrumentation/active_job/handlers/default.rb,
lib/opentelemetry/instrumentation/active_job/handlers/enqueue.rb,
lib/opentelemetry/instrumentation/active_job/handlers/perform.rb

Overview

Module that contains custom event handlers, which are used to generate spans per event

Defined Under Namespace

Classes: Default, Enqueue, Perform

Constant Summary collapse

EVENT_NAMESPACE = 
'active_job'

Class Method Summary collapse

Class Method Details

.subscribe ⇒ Object

Note:

this method is not thread safe and should not be used in a multi-threaded context

Note:

Why no perform_start? This event causes much heartache as it is the first in a series of events that is triggered. It should not be the ingress span because it does not measure anything. https://github.com/rails/rails/blob/v6.1.7.6/activejob/lib/active_job/instrumentation.rb#L14 https://github.com/rails/rails/blob/v7.0.8/activejob/lib/active_job/instrumentation.rb#L19

Subscribes Event Handlers to relevant ActiveJob notifications

The following events are recorded as spans:

  • enqueue
  • enqueue_at
  • enqueue_retry
  • perform
  • retry_stopped
  • discard

Ingress and Egress spans (perform, enqueue, enqueue_at) use Messaging semantic conventions for naming the span, while internal spans keep their ActiveSupport event name.



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# File 'lib/opentelemetry/instrumentation/active_job/handlers.rb', line 40

def subscribe
  return unless Array(@subscriptions).empty?

  mapper = Mappers::Attribute.new
  config = ActiveJob::Instrumentation.instance.config
  parent_span_provider = OpenTelemetry::Instrumentation::ActiveJob

  # TODO, use delegation instead of inheritance
  default_handler = Handlers::Default.new(parent_span_provider, mapper, config)
  enqueue_handler = Handlers::Enqueue.new(parent_span_provider, mapper, config)
  perform_handler = Handlers::Perform.new(parent_span_provider, mapper, config)

  handlers_by_pattern = {
    'enqueue' => enqueue_handler,
    'enqueue_at' => enqueue_handler,
    'enqueue_retry' => default_handler,
    'perform' => perform_handler,
    'retry_stopped' => default_handler,
    'discard' => default_handler
  }

  @subscriptions = handlers_by_pattern.map do |key, handler|
    ::ActiveSupport::Notifications.subscribe("#{key}.#{EVENT_NAMESPACE}", handler)
  end
end

.unsubscribe ⇒ Object

Note:

this method is not thread-safe and should not be used in a multi-threaded context

Removes Event Handler Subscriptions for ActiveJob notifications



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# File 'lib/opentelemetry/instrumentation/active_job/handlers.rb', line 68

def unsubscribe
  @subscriptions&.each { |subscriber| ::ActiveSupport::Notifications.unsubscribe(subscriber) }
  @subscriptions = nil
end