The rabbitmq-diagnostics check_virtual_hosts command can be used to perform a simple health check of the virtual hosts.
Usually, something like this will be returned.
Checking if all vhosts are running on node rabbit@server001 ... Node rabbit@server001 reported all vhosts as running
However, if one or more virtual hosts are not running, something like this should be returned. In this example, the default / (forward slash) virtual host and the foo and bar virtual hosts are not running. In this scenario, you can try to start the virtual hosts using the rabbitmqctl restart_vhost command.
Some virtual hosts on node rabbit@server001 are down: / foo bar