(1) Update system's ulimit.
$sudo pico /etc/security/limits.d/mylimits.conf
* soft nofile 300000 * hard nofile 300000 * soft nproc 300000 * hard nproc 300000
(2) Update rabbitMQ config
$sudo pico /etc/default/rabbitmq-server
ulimit -n 300000
(3) Restart rabbitMQ
$sudo service rabbitmq-server restart