I used MacPorts to install RabbitMq 2.2.0 on my Mc OS X (Snow Leopard) laptop. After installing I tried running the command sudo rabbitmq-server and I get an error saying there's already a rabbitmq process running. The startupitem.log from /opt/local/var/log/rabbitmq indicated the broker started successfully, using the domain localhost. I was expecting it to use the domain mycomputername since that is what i have configured in my /etc/hosts file. I cannot connect to the node rabbit@mycomputername when I try to run the command rabbitmqctl. Somehow rabbitmq-server is using localhost domain while rabbitmqctl is using mycomputername domain.
Did more digging and found out that the daemon generated by MacPorts after it installed RabbitMQ was getting spawned when my computer starts up. But the problem is it's using localhost as the domain instead of mycomputername. When I try to kill that spawned process, rabbitmq automatically re-starts and now using the node rabbit@mycomputername. So I can now use rabbitmqctl command and query the rabbitmq server. To permanently fix the issue, I have to remove the plist file org.macports.rabbitmq-server.plit which defines the start/stop behavior of rabbitmq-server which is registered as a global daemon process that will automatically kick-off when my computer boots up.
After removing the plist file, and manually starts rabbitmq by typing sudo rabbitmq-server, I no longer see any errors. I wasn't sure why MacPorts generated that plist file that always uses localhost as it's domain instead of mycomputername when it starts rabbitmq-server initially.
If your erl_crash.dump file contains the string below you might have the same problem. Either check to see if you have configured your /etc/hosts file properly or that you are having the exact same problem I just came across with.
'Warning: No HOSTSFILE specified!'
'Warning: No NAMESERVER or RESOLVFILE specified!'
Glad I can start playing around with RabbitMQ!