OpenStack uses a message queue to coordinate operations and status information among services. The message queue service typically runs on the controller node. OpenStack supports several message queue services including RabbitMQ, Qpid, and ZeroMQ. However, most distributions that package OpenStack support a particular message queue service. This guide implements the RabbitMQ message queue service because most distributions support it. If you prefer to implement a different message queue service, consult the documentation associated with it. Install the package: # apt-get install rabbitmq-server # yum install rabbitmq-server # zypper install rabbitmq-server Start the message queue service and configure it to start when the system boots: # systemctl enable rabbitmq-server.service # systemctl start rabbitmq-server.service Add the openstack user: # rabbitmqctl add_user openstack RABBIT_PASS Creating user "openstack" ... ...done. Replace RABBIT_PASS with a suitable password. Permit configuration, write, and read access for the openstack user: # rabbitmqctl set_permissions openstack ".*" ".*" ".*" Setting permissions for user "openstack" in vhost "/" ... ...done.