Module: NewRelic::Control::Instrumentation

Included in:
NewRelic::Control
Defined in:
lib/new_relic/control/instrumentation.rb

Overview

Contains methods that relate to adding and executing files that contain instrumentation for the Ruby Agent

Instance Method Summary collapse

Instance Method Details

#add_instrumentation(pattern) ⇒ Object

Add instrumentation. Don’t call this directly. Use NewRelic::Agent#add_instrumentation. This will load the file synchronously if we’ve already loaded the default instrumentation, otherwise instrumentation files specified here will be deferred until all instrumentation is run

This happens after the agent has loaded and all dependencies are ready to be instrumented



41
42
43
44
45
46
47
 
# File 'lib/new_relic/control/instrumentation.rb', line 41

def add_instrumentation pattern
  if @instrumented
    load_instrumentation_files pattern
  else
    @instrumentation_files << pattern
  end
end

#install_instrumentation ⇒ Object

Signals the agent that it’s time to actually load the instrumentation files. May be overridden by subclasses



51
52
53
 
# File 'lib/new_relic/control/instrumentation.rb', line 51

def install_instrumentation
  _install_instrumentation
end

#install_shim ⇒ Object

Install stubs to the proper location so the app code will not fail if the agent is not running.



28
29
30
31
32
 
# File 'lib/new_relic/control/instrumentation.rb', line 28

def install_shim
  # Once we install instrumentation, you can't undo that by installing the shim.
  raise "Cannot install the Agent shim after instrumentation has already been installed!" if @instrumented
  NewRelic::Agent.agent = NewRelic::Agent::ShimAgent.instance
end

#load_instrumentation_files(pattern) ⇒ Object

Adds a list of files in Dir.glob format (e.g. ‘/app/foo/*/_instrumentation.rb’) This requires the files within a rescue block, so that any errors within instrumentation files do not affect the overall agent or application in which it runs.



16
17
18
19
20
21
22
23
24
 
# File 'lib/new_relic/control/instrumentation.rb', line 16

def load_instrumentation_files pattern
  Dir.glob(pattern) do |file|
    begin
      require file.to_s
    rescue => e
      ::NewRelic::Agent.logger.warn "Error loading instrumentation file '#{file}':", e
    end
  end
end

#load_samplers ⇒ Object

adds samplers to the stats engine so that they run every minute. This is dynamically recognized by any class that subclasses NewRelic::Agent::Sampler



58
59
60
61
62
 
# File 'lib/new_relic/control/instrumentation.rb', line 58

def load_samplers
  NewRelic::Agent::Sampler.sampler_classes.each do | subclass |
    NewRelic::Agent.instance.add_harvest_sampler(subclass)
  end
end