AWS Elastic Beanstalk Passenger (standalone) configuration change to use "--spawn-method conservative". Usage: add it to your .ebextensions directory and reference it in the container_commands section in .ebextensions/environment.config.

environment.config

container_commands:
  passenger-config:
    command: "/bin/bash .ebextensions/spawn-method-conservative.sh"

spawn-method-conservative.sh

#!/bin/bash

# add "--spawn-method conservative" to passenger config if it doesn't exist
sed -E -i.bak '/--spawn-method conservative/! s,(passenger start .*)\\,\1--spawn-method conservative \\,g' /etc/init.d/passenger