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