Module: NewRelic::Agent::Agent::InstanceMethods::Start

Included in:
NewRelic::Agent::Agent::InstanceMethods
Defined in:
lib/new_relic/agent/agent.rb

Overview

Herein lies the corpse of the former ‘start’ method. May its unmatched flog score rest in pieces.

Instance Method Summary collapse

Instance Method Details

#already_started? ⇒ Boolean

Check whether we have already started, which is an error condition

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/agent.rb', line 310

def already_started?
  if started?
    control.log!("Agent Started Already!", :error)
    true
  end
end

#check_config_and_start_agent ⇒ Object

Sanity-check the agent configuration and start the agent, setting up the worker thread and the exit handler to shut down the agent



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# File 'lib/new_relic/agent/agent.rb', line 457

def check_config_and_start_agent
  return unless monitoring? && has_correct_license_key?
  return if using_forking_dispatcher?
  connect_in_foreground if Agent.config[:sync_startup]
  start_worker_thread
  install_exit_handler
end

#connect_in_foreground ⇒ Object

Connecting in the foreground blocks further startup of the agent until we have a connection - useful in cases where you’re trying to log a very-short-running process and want to get statistics from before a server connection (typically 20 seconds) exists



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# File 'lib/new_relic/agent/agent.rb', line 348

def connect_in_foreground
  NewRelic::Agent.disable_all_tracing { connect(:keep_retrying => false) }
end

#correct_license_length ⇒ Object

A license key is an arbitrary 40 character string, usually looks something like a SHA1 hash



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# File 'lib/new_relic/agent/agent.rb', line 441

def correct_license_length
  key = Agent.config[:license_key]
  log_unless((key.length == 40), :error, "Invalid license key: #{key}")
end

#disabled? ⇒ Boolean

The agent is disabled when it is not force enabled by the ‘agent_enabled’ option (e.g. in a manual start), or enabled normally through the configuration file

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/agent.rb', line 320

def disabled?
  !Agent.config[:agent_enabled]
end

#has_correct_license_key? ⇒ Boolean

A correct license key exists and is of the proper length

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/agent.rb', line 435

def has_correct_license_key?
  has_license_key? && correct_license_length
end

#has_license_key? ⇒ Boolean

Tell the user when the license key is missing so they can fix it by adding it to the file

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/agent.rb', line 429

def has_license_key?
  log_unless(Agent.config[:license_key], :warn,
             "No license key found in newrelic.yml config.")
end

#install_exit_handler ⇒ Object

Installs our exit handler, which exploits the weird behavior of at_exit blocks to make sure it runs last, by doing an at_exit within an at_exit block.



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# File 'lib/new_relic/agent/agent.rb', line 369

def install_exit_handler
  if Agent.config[:send_data_on_exit] && !weird_ruby?
    at_exit do
      # Workaround for MRI 1.9 bug that loses exit codes in at_exit blocks.
      # This is necessary to get correct exit codes for the agent's
      # test suites.
      # http://bugs.ruby-lang.org/issues/5218
      if defined?(RUBY_ENGINE) && RUBY_ENGINE == "ruby" && RUBY_VERSION.match(/^1\.9/)
        exit_status = $!.status if $!.is_a?(SystemExit)
        shutdown
        exit exit_status if exit_status
      else
        shutdown
      end
    end
  end
end

#log_app_names ⇒ Object

Logs the configured application names



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# File 'lib/new_relic/agent/agent.rb', line 334

def log_app_names
  names = Agent.config.app_names
  if names.respond_to?(:any?) && names.any?
    log.info "Application: #{names.join(", ")}"
  else
    log.error 'Unable to determine application name. Please set the application name in your newrelic.yml or in a NEW_RELIC_APP_NAME environment variable.'
  end
end

#log_dispatcher ⇒ Object

Logs the dispatcher to the log file to assist with debugging. When no debugger is present, logs this fact to assist with proper dispatcher detection



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# File 'lib/new_relic/agent/agent.rb', line 327

def log_dispatcher
  dispatcher_name = Agent.config[:dispatcher].to_s
  return if log_if(dispatcher_name.empty?, :info, "No dispatcher detected.")
  log.info "Dispatcher: #{dispatcher_name}"
end

#log_if(boolean, level, message) ⇒ Object

A helper method that logs a condition if that condition is true. Mentally cleaner than having every method set a local and log if it is true



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

def log_if(boolean, level, message)
  self.log.send(level, message) if boolean
  boolean
end

#log_unless(boolean, level, message) ⇒ Object

A helper method that logs a condition unless that condition is true. Mentally cleaner than having every method set a local and log unless it is true



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# File 'lib/new_relic/agent/agent.rb', line 415

def log_unless(boolean, level, message)
  self.log.send(level, message) unless boolean
  boolean
end

#log_version_and_pid ⇒ Object

Classy logging of the agent version and the current pid, so we can disambiguate processes in the log file and make sure they’re running a reasonable version



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# File 'lib/new_relic/agent/agent.rb', line 400

def log_version_and_pid
  log.info "New Relic Ruby Agent #{NewRelic::VERSION::STRING} Initialized: pid = #{$$}"
end

#monitoring? ⇒ Boolean

Warn the user if they have configured their agent not to send data, that way we can see this clearly in the log file

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/agent.rb', line 422

def monitoring?
  log_unless(Agent.config[:monitor_mode], :warn,
             "Agent configured not to send data in this environment.")
end

#notify_log_file_location ⇒ Object

Tells us in the log file where the log file is located. This seems redundant, but can come in handy when we have some log file path set by the user which parses incorrectly, sending the log file to who-knows-where



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# File 'lib/new_relic/agent/agent.rb', line 391

def notify_log_file_location
  log_file = NewRelic::Control.instance.log_file
  log_if(File.exists?(log_file.to_s), :info,
         "Agent Log at #{log_file}")
end

#using_forking_dispatcher? ⇒ Boolean

If we’re using a dispatcher that forks before serving requests, we need to wait until the children are forked before connecting, otherwise the parent process sends odd data

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/agent.rb', line 449

def using_forking_dispatcher?
  log_if([:passenger, :unicorn].include?(Agent.config[:dispatcher]),
         :info, "Connecting workers after forking.")
end

#using_sinatra? ⇒ Boolean

If we’re using sinatra, old versions run in an at_exit block so we should probably know that

Returns:

  • (Boolean) 


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

def using_sinatra?
  defined?(Sinatra::Application)
end

#weird_ruby? ⇒ Boolean

we should not set an at_exit block if people are using these as they don’t do standard at_exit behavior per MRI/YARV

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/agent.rb', line 360

def weird_ruby?
  NewRelic::LanguageSupport.using_engine?('rbx') ||
    NewRelic::LanguageSupport.using_engine?('jruby') ||
    using_sinatra?
end