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 311

def already_started?
  if started?
    ::NewRelic::Agent.logger.error("Agent Started Already!")
    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 470

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 362

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 446

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

#defer_for_resque? ⇒ Boolean

Return true if we’re using resque and it hasn’t had a chance to (potentially) daemonize itself. This avoids hanging when there’s a Thread started before Resque calls Process.daemon (Jira RUBY-857)

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/agent.rb', line 462

def defer_for_resque?
  NewRelic::Agent.config[:dispatcher] == :resque &&
    !NewRelic::Agent::PipeChannelManager.listener.started?
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 321

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 440

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 433

def has_license_key?
  log_unless(Agent.config[:license_key], :warn,
             "No license key found in newrelic.yml config. " +
             "This often means your newrelic.yml is missing a section for the running environment '#{NewRelic::Control.instance.env}'")
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 383

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 348

def log_app_names
  names = Agent.config.app_names
  if names.respond_to?(:any?) && names.any?
    ::NewRelic::Agent.logger.info "Application: #{names.join(", ")}"
  else
    ::NewRelic::Agent.logger.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 341

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

#log_environment ⇒ Object

Log the environment the app thinks it’s running in. Useful in debugging, as this is the key for config YAML lookups.



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

def log_environment
  ::NewRelic::Agent.logger.info "Environment: #{NewRelic::Control.instance.env}"
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 411

def log_if(boolean, level, message)
  ::NewRelic::Agent.logger.send(level, message) if boolean
  boolean
end

#log_startup ⇒ Object

Log startup information that we almost always want to know



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# File 'lib/new_relic/agent/agent.rb', line 326

def log_startup
  log_environment
  log_dispatcher
  log_app_names
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 419

def log_unless(boolean, level, message)
  ::NewRelic::Agent.logger.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 404

def log_version_and_pid
  ::NewRelic::Agent.logger.debug "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 426

def monitoring?
  log_unless(Agent.config[:monitor_mode], :warn,
             "Agent configured not to send data in this environment.")
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 454

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 368

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 374

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