Control when the Ruby agent starts

Problem

The Ruby agent is not properly starting or is not reporting data to New Relic.

Solution

To solve this problem:

Check your Ruby agent version.

Check your Ruby agent version, and update if necessary.

Check the app environment used.

When the newrelic_rpm Ruby gem is required in your application environment, it will attempt to determine whether to start monitoring automatically and begin transmitting metrics to New Relic, or to remain disabled.

• Production and staging: The agent typically is configured to monitor automatically in these environments.
• Test and development: The agent typically remains disabled in these environments.

To control this logic, set the monitor_mode configuration key to true or false in each environment section of newrelic.yml.

Force the agent to start.

To override the agent's auto-start logic, the easiest mechanism is to set a NEW_RELIC_AGENT_ENABLED=true environment variable; for example:

NEW_RELIC_AGENT_ENABLED=true rake assets:precompile

Customize the auto-start configuration variables.

If you are running Ruby agent version 3.6.1 or higher, there are a few reasons the agent will refuse to start:

• The agent detects it is in an interactive session; for example, a rails console or irb session.
• The agent detects it is in one of Rails' built-in rake tasks; for example, assets:precompile or db:migrate.

You can use configuration variables in your Ruby agent newrelic.yml file to customize auto-start behavior for constants, script names, and rake tasks.

Variable	Description
Constants	autostart.denylisted_constants Ruby constants that should prevent the agent from starting. Accepts a comma separated list. Defaults to "Rails::Console". Set to "" to tell the agent to start when Rails::Console is in the environment.
Rake tasks	autostart.denylisted_rake_tasks Rake tasks you do not want the agent to monitor; for example, assets:precompile. Accepts a comma-separated list. We do not disable the Ruby agent in all rake tasks, because tasks like resque:work generally are monitored.
Executables	autostart.denylisted_executables A list of script names, such as irb, that will prevent the agent from starting automatically. Accepts a comma-separated list. Set this to "rake" to prevent the agent from starting in rake tasks, or "rake,my_ruby_script.rb" to prevent it from starting in rake and a custom script.