Delayed::Job instrumentation

The Ruby agent has built-in instrumentation for the Delayed::Job library. No additional instrumentation is required.

Viewing background tasks

As long as the New Relic Ruby agent's gem or plugin is loaded before the Delayed::Job worker starts, all tasks will be monitored with the same level of detail as controller actions. To view the actions themselves:

1. Go to one.newrelic.com > All capabilities > APM & services > (select an app) > Monitor > Transactions.
2. From the APM Transactions page, select Other transactions.

Adding Custom Attributes

If you want to add custom attributes to your Delayed::Job transactions, you can write a Delayed::Job plugin through a lifecycle hook and add those attributes to the transaction for each executed job.

1. Create a plugin with the following structure:

   module NewRelicInstrumenter
     class DelayedJobPlugin < Delayed::Plugin
       callbacks do |lifecycle|
         lifecycle.around(:invoke_job) do |job, *args, &block|
           # Forward the call to the next callback in the callback chain
           ::NewRelic::Agent.add_custom_attributes(
             {
               # Any custom attributes go here -- from here you can access info
               # about the job like run_at, created_at, etc
               my_custom_attribute: "my_custom_attribute_value"
             }
           )
           block.call(job, *args)
         end
       end
     end
   end

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2. Add the plugin to Delayed::Job in the initializer in the config/initializers/delayed_job.rb file:

   require "new_relic_instrumenter"
   
   Delayed::Worker.plugins << NewRelicInstrumenter::DelayedJobPlugin

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Troubleshooting

The Ruby agent depends on being able to identify that it is running under Delayed::Job in order to correctly set up instrumentation. To do this, it examines the script name (the $0 variable in Ruby) to see whether it ends with delayed_job.

If you have renamed the script you use to start your delayed_job workers to something else, or if you have a custom script with a different name, you will need to explicitly tell the agent that you are using Delayed::Job by setting the NEW_RELIC_DISPATCHER environment variable to delayed_job when starting your Delayed::Job workers. For example:

$
NEW_RELIC_DISPATCHER=delayed_job bundle exec ./script/my_custom_script

If it appears that jobs are not being monitored, review the newrelic_agent.log file generated when the worker starts up. It should indicate whether the agent detects Delayed and communicates with the server. If you do not find a log, or if you still cannot determine why the jobs do not appear, get support at support.newrelic.com.