Class: Appsignal::Agent

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

Constant Summary collapse

ACTION = 
'log_entries'.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Agent

Returns a new instance of Agent.



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# File 'lib/appsignal/agent.rb', line 8

def initialize
  return unless Appsignal.active?
  if Appsignal.config.env == 'development'
    @sleep_time = 10.0
  else
    @sleep_time = 60.0
  end
  @master_pid = Process.pid
  @pid = @master_pid
  @aggregator = Aggregator.new
  @transmitter = Transmitter.new(ACTION)
  subscribe
  start_thread
  Appsignal.logger.info('Started Appsignal agent')
end

Instance Attribute Details

#active ⇒ Object

Returns the value of attribute active.



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# File 'lib/appsignal/agent.rb', line 5

def active
  @active
end

#aggregator ⇒ Object

Returns the value of attribute aggregator.



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# File 'lib/appsignal/agent.rb', line 5

def aggregator
  @aggregator
end

#master_pid ⇒ Object

Returns the value of attribute master_pid.



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# File 'lib/appsignal/agent.rb', line 5

def master_pid
  @master_pid
end

#paused ⇒ Object

Returns the value of attribute paused.



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# File 'lib/appsignal/agent.rb', line 5

def paused
  @paused
end

#pid ⇒ Object

Returns the value of attribute pid.



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# File 'lib/appsignal/agent.rb', line 5

def pid
  @pid
end

#sleep_time ⇒ Object

Returns the value of attribute sleep_time.



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# File 'lib/appsignal/agent.rb', line 5

def sleep_time
  @sleep_time
end

#subscriber ⇒ Object

Returns the value of attribute subscriber.



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# File 'lib/appsignal/agent.rb', line 5

def subscriber
  @subscriber
end

#thread ⇒ Object

Returns the value of attribute thread.



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# File 'lib/appsignal/agent.rb', line 5

def thread
  @thread
end

#transmitter ⇒ Object

Returns the value of attribute transmitter.



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# File 'lib/appsignal/agent.rb', line 5

def transmitter
  @transmitter
end

Instance Method Details

#clear_queue ⇒ Object 



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# File 'lib/appsignal/agent.rb', line 111

def clear_queue
  Appsignal.logger.debug('Clearing queue')
  # Replace aggregator while making sure no thread
  # is adding to it's queue
  Thread.exclusive do
    @aggregator = Aggregator.new
  end
end

#enqueue(transaction) ⇒ Object 



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# File 'lib/appsignal/agent.rb', line 82

def enqueue(transaction)
  forked! if @pid != Process.pid
  if Appsignal.is_ignored_action?(transaction.action)
    Appsignal.logger.debug("Ignoring transaction: #{transaction.request_id} (#{transaction.action})")
    return
  end
  aggregator.add(transaction)
end

#forked! ⇒ Object 



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# File 'lib/appsignal/agent.rb', line 120

def forked!
  Appsignal.logger.info('Forked worker process')
  @pid = Process.pid
  Thread.exclusive do
    @aggregator = Aggregator.new
  end
  resubscribe
  restart_thread
end

#restart_thread ⇒ Object 



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# File 'lib/appsignal/agent.rb', line 41

def restart_thread
  Appsignal.logger.debug 'Restarting agent thread'
  stop_thread
  start_thread
end

#resubscribe ⇒ Object 



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# File 'lib/appsignal/agent.rb', line 70

def resubscribe
  Appsignal.logger.debug('Resubscribing to notifications')
  unsubscribe
  subscribe
end

#send_queue ⇒ Object 



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# File 'lib/appsignal/agent.rb', line 91

def send_queue
  Appsignal.logger.debug('Sending queue')
  # Replace aggregator while making sure no thread
  # is adding to it's queue
  aggregator_to_be_sent = nil
  Thread.exclusive do
    aggregator_to_be_sent = aggregator
    @aggregator = Aggregator.new
  end

  begin
    handle_result(
      transmitter.transmit(aggregator_to_be_sent.post_processed_queue!)
    )
  rescue Exception => ex
    Appsignal.logger.error "#{ex.class} while sending queue: #{ex.message}"
    Appsignal.logger.error ex.backtrace.join('\n')
  end
end

#shutdown(send_current_queue = false, reason = nil) ⇒ Object 



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# File 'lib/appsignal/agent.rb', line 130

def shutdown(send_current_queue=false, reason=nil)
  Appsignal.logger.info("Shutting down agent (#{reason})")
  unsubscribe
  stop_thread
  send_queue if send_current_queue && @aggregator.has_transactions?
end

#start_thread ⇒ Object 



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# File 'lib/appsignal/agent.rb', line 24

def start_thread
  Appsignal.logger.debug('Starting agent thread')
  @thread = Thread.new do
    begin
      sleep(rand(sleep_time))
      loop do
        send_queue if aggregator.has_transactions?
        Appsignal.logger.debug("Sleeping #{sleep_time}")
        sleep(sleep_time)
      end
    rescue Exception=>ex
      Appsignal.logger.error "#{ex.class} in agent thread: '#{ex.message}'"
      Appsignal.logger.error ex.backtrace.join('\n')
    end
  end
end

#stop_thread ⇒ Object 



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# File 'lib/appsignal/agent.rb', line 47

def stop_thread
  if @thread && @thread.alive?
    Appsignal.logger.debug 'Stopping agent thread'
    Thread.kill(@thread)
  end
end

#subscribe ⇒ Object 



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# File 'lib/appsignal/agent.rb', line 54

def subscribe
  Appsignal.logger.debug('Subscribing to notifications')
  # Subscribe to notifications that don't start with a !
  @subscriber = ActiveSupport::Notifications.subscribe(/^[^!]/) do |*args|
    if Appsignal::Transaction.current
      event = ActiveSupport::Notifications::Event.new(*args)
      if event.name.start_with?('process_action')
        Appsignal::Transaction.current.set_process_action_event(event)
      elsif event.name.start_with?('perform_job')
        Appsignal::Transaction.current.set_perform_job_event(event)
      end
      Appsignal::Transaction.current.add_event(event) unless paused
    end
  end
end

#unsubscribe ⇒ Object 



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# File 'lib/appsignal/agent.rb', line 76

def unsubscribe
  Appsignal.logger.debug('Unsubscribing from notifications')
  ActiveSupport::Notifications.unsubscribe(@subscriber)
  @subscriber = nil
end