Migrating from Qpid to Rabbitmq

Option 1: All at once

Shut down all your OpenStack services. On all hosts in your OpenStack deployment, run:
```
  openstack-service stop
```

Shut down and disable qpidd:

  service qpidd stop
  chkconfig rabbitmq-server off

On your controller, install rabbitmq:
```
  yum install rabbitmq-server
```

Start rabbitmq and enable:

  service rabbitmq-server start
  chkconfig rabbitmq-server on

For each service, update the relevant configuration file to use rabbitmq instead of qpid. You can follow the procedures in this document.
When you have finished configuring all the services on all your OpenStack hosts, restart your OpenStack services. On each host in your deployment, run:
```
  openstack-service start
```

Option 2: Service by service

It is possible to run the rabbitmq server in parallel with (and on a different port from) qpid. This permits you to make changes to one service at a time without disrupting your entire environment.

On your controller, install the rabbitmq-server package:
```
  yum install rabbitmq-server
```
Edit /etc/rabbitmq/rabbitmq-env.conf and change:
```
  RABBITMQ_NODE_PORT=5672       
```
To:
```
  RABBITMQ_NODE_PORT=5672       
```
This will configure rabbitmq-server to bind to port 5673 instead of the normal AMQP port, 5672.

Start and enable rabbitmq:

  service rabbitmq-server start
  chkconfig rabbitmq-server on

For each service, modify the appropriate configuration files as per this document, and then restart the service.

Note that you will need to configure each service to use port 5673 for rabbitmq rather than the default port. This may also require appropriate firewall changes to permit access to port 5673 on your controller.

For example, to migrate your Nova services from qpid to rabbitmq:
1. Edit /etc/nova/nova.conf on both the controller and compute hosts.
2. Restart Nova services on the controller and compute hosts:
```
  controller# openstack-service restart nova
```
  And:
```
  compute# openstack-service restart nova
```
After completing the configuration changes for all of your services, stop and disable the qpid service on your controller:
```
     service qpidd stop
     chkconfig qpidd off
```

At this point, all of your services are now talking to rabbitmq on port 5673.

You can verify that you have completed the migration by using the netstat or ss command to look for ESTABLISHED connections to port 5672. E.g:

# netstat -tan | grep 5672 | grep ESTABLISHED

After completing the above steps, there should be no output from this command. All of your services should now be using port 5673:

# netstat -tan | grep 5673 | grep ESTABLISHED

Which will generate output like:

tcp        0      0 127.0.0.1:37110         127.0.0.1:5673          ESTABLISHED
tcp        0      0 127.0.0.1:37108         127.0.0.1:5673          ESTABLISHED
tcp        0      0 192.168.122.162:54024   192.168.122.162:5673    ESTABLISHED
tcp        0      0 127.0.0.1:37100         127.0.0.1:5673          ESTABLISHED
tcp        0      0 192.168.122.162:54595   192.168.122.162:5673    ESTABLISHED
tcp        0      0 127.0.0.1:37109         127.0.0.1:5673          ESTABLISHED