The first step is to check if the rabbitmq-server process is still running on the affected node, to do this run the following monit [3] command:
monit summary
This will report if the Erlang process is still running as far as monit is concerned.
To test if the RabbitMQ process is running, you can run one of the following commands to see if it reports back the current status of the cluster.
rabbitmqctl report rabbitmqctl status
See "RabbitMQ CLI" section [1]
If you cannot connect to RabbitMQ via the CLI then you should first try and restart the rabbitmq-server process using monit.
1. monit stop rabbitmq-server
2. Ensure the process has stopped using monit summary
3. monit start rabbitmq-server
For RabbitMQ for PCF, it is recommended that you do not start/stop RabbitMQ using rabbitmqctl , along with running others commands as outlined in the clustering plugin [2] as this is used by the service to control the cluster.