Module: NewRelic::Agent::Instrumentation::Rack
- Includes:
- ControllerInstrumentation
- Defined in:
- lib/new_relic/agent/instrumentation/rack.rb
Overview
Instrumentation for Rack
New Relic will instrument a #call method as if it were a controller action, collecting transaction traces and errors. The middleware will be identified only by its class, so if you want to instrument multiple actions in a middleware, you need to use NewRelic::Agent::Instrumentation::ControllerInstrumentation::ClassMethods#add_transaction_tracer
Example:
require 'newrelic_rpm'
require 'new_relic/agent/instrumentation/rack'
class Middleware
def call(env)
...
end
# Do the include after the call method is defined:
include NewRelic::Agent::Instrumentation::Rack
end
Instrumenting Metal and Cascading Middlewares
Metal apps and apps belonging to Rack::Cascade middleware follow a convention of returning a 404 for all requests except the ones they are set up to handle. This means that New Relic needs to ignore these calls when they return a 404.
In these cases, you should not include or extend the Rack module but instead include NewRelic::Agent::Instrumentation::ControllerInstrumentation. Here’s how that might look for a Metal app:
require 'new_relic/agent/instrumentation/controller_instrumentation'
class MetalApp
extend NewRelic::Agent::Instrumentation::ControllerInstrumentation
def self.call(env)
if should_do_my_thing?
perform_action_with_newrelic_trace(:category => :rack) do
return my_response(env)
end
else
return [404, {"Content-Type" => "text/html"}, ["Not Found"]]
end
end
end
Overriding the metric name
By default the middleware is identified only by its class, but if you want to be more specific and pass in name, then omit including the Rack instrumentation and instead follow this example:
require 'newrelic_rpm'
require 'new_relic/agent/instrumentation/controller_instrumentation'
class Middleware
include NewRelic::Agent::Instrumentation::ControllerInstrumentation
def call(env)
...
end
add_transaction_tracer :call, :category => :rack, :name => 'my app'
end
Constant Summary
Constants included from QueueTime
QueueTime::ALL_MIDDLEWARE_METRIC, QueueTime::ALL_QUEUE_METRIC, QueueTime::ALL_SERVER_METRIC, QueueTime::ALT_QUEUE_HEADER, QueueTime::APP_HEADER, QueueTime::HEADER_REGEX, QueueTime::HEROKU_QUEUE_HEADER, QueueTime::MAIN_HEADER, QueueTime::MIDDLEWARE_HEADER, QueueTime::MIDDLEWARE_METRIC, QueueTime::QUEUE_HEADER, QueueTime::SERVER_METRIC
Class Method Summary collapse
-
.extended(middleware) ⇒ Object
:nodoc:.
-
.included(middleware) ⇒ Object
:nodoc:.
Instance Method Summary collapse
Methods included from ControllerInstrumentation
#newrelic_metric_path, #perform_action_with_newrelic_trace
Methods included from QueueTime
Class Method Details
.extended(middleware) ⇒ Object
:nodoc:
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# File 'lib/new_relic/agent/instrumentation/rack.rb', line 87 def self.extended middleware #:nodoc: middleware.class_eval do class << self alias call_without_newrelic call alias call call_with_newrelic end end end |
.included(middleware) ⇒ Object
:nodoc:
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# File 'lib/new_relic/agent/instrumentation/rack.rb', line 80 def self.included middleware #:nodoc: middleware.class_eval do alias call_without_newrelic call alias call call_with_newrelic end end |
Instance Method Details
#call_with_newrelic(*args) ⇒ Object
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# File 'lib/new_relic/agent/instrumentation/rack.rb', line 71 def call_with_newrelic(*args) @newrelic_request = ::Rack::Request.new(args.first) perform_action_with_newrelic_trace(:category => :rack, :request => @newrelic_request) do result = call_without_newrelic(*args) # Ignore cascaded calls MetricFrame.abort_transaction! if result.first == 404 result end end |
#newrelic_request_headers ⇒ Object
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# File 'lib/new_relic/agent/instrumentation/rack.rb', line 68 def newrelic_request_headers @newrelic_request.env end |