RabbitMQ reports Error unable to connect to node rabbit@localhost nodedown and solutions

An error occurred when using the following command

rabbitmqctl add_user openstack RABBIT_PASS 

The error is as follows:

Solution:
First check the mq process

ps -ef | grep rabbitmq

Kill the mq process queried above

ps -ef | grep rabbitmq | grep -v grep | awk '{print $2}' | xargs kill -9

Restart mq

rabbitmq-server -detached

Query the status of mq

rabbitmqctl status