Storm High Availability and Failover - Real-time Analytics with Storm and Cassandra - page 96

The cluster can be accessed at http:/ /<hostip>:15672 (username: guest , pass-
word: guest ), if the UI is enabled.
Enabling the RabbitMQ UI
Perform the following steps to enable the RabbitMQ UI:
1. Execute the following command:
sudo /usr/lib/rabbitmq/bin/rabbitmq-plugins enable
rabbitmq_management
2. The preceding command will result in the following output:
The following plugins have been enabled:
mochiweb
webmachine
rabbitmq_mochiweb
amqp_client
rabbitmq_management_agent
rabbitmq_management
Plugin configuration has changed. Restart RabbitMQ
for changes to take effect.
3. Repeat the preceding steps on all nodes of the cluster.
4. Restart each node using the following command:
sudo service rabbitmq-server restart
5. Access the UI using the http://<hostip>:15672 link. The default user-
name and password is guest .
Creating mirror queues for high availability
In this section, we talk about a special kind of queues that guarantee high availability over
the RabbitMQ default queues. By default, the queues that we create are located on a single
node based on the order in which they are declared, and this can become the single point
of failure. Let's look at an example. I have a cluster of two RabbitMQ nodes, rabbit1
and rabbit2 , and I declare one exchange over my cluster, say, myrabbitxchange .
Let's say by the order of execution, the queue is created in rabbit1 . Now if rabbit1
goes down, then the queue is gone and the clients will not be able to publish to it.