How to Deploy a High‑Availability RabbitMQ Cluster on CentOS 7

RabbitMQ Cluster Deployment

Preparation

Step 1: Three Linux systems (CentOS 7.3)

Hostname

IP Address

node1

192.168.137.138

node2

192.168.137.139

node3

192.168.137.140

## All node operations: host name resolution
# vim /etc/hosts
...
192.168.137.139  node2
192.168.137.140  node3
192.168.137.138  node1
...

# node1 operations: password‑less login to other hosts
ssh-keygen
ssh-copy-id node2
ssh-copy-id node3

Deploy RabbitMQ Cluster

Step 1: Install packages

# Install Erlang and RabbitMQ on all nodes
yum install -y erlang rabbitmq-server.noarch
systemctl start rabbitmq-server.service
systemctl status rabbitmq-server.service
systemctl enable rabbitmq-server.service

Step 2: Optional checks

# Check port 5672 (RabbitMQ default)
ss -ntl | grep 5672
# Main configuration file directory
/etc/rabbitmq/rabbitmq.config

Step 3: Add an OpenStack user with password RABBIT_PASS and grant administrator rights

rabbitmqctl add_user openstack RABBIT_PASS
rabbitmqctl set_permissions openstack ".*" ".*" ".*"
rabbitmqctl set_user_tags openstack administrator

Step 4: Edit the RabbitMQ environment file

vim /etc/rabbitmq/rabbitmq-env.conf
...
RABBITMQ_NODE_PORT=5672
ulimit -S -n 4096
RABBITMQ_SERVER_ERL_ARGS="+K true +A30 +P 1048576 -kernel inet_default_connect_options [{nodelay,true},{raw,6,18,<<5000:64/native>>}] -kernel inet_default_listen_options [{raw,6,18,<<5000:64/native>>}]"
RABBITMQ_NODE_IP_ADDRESS=172.16.254.60
...

Step 5: Copy the environment file to the other two nodes and adjust the IP address accordingly

scp /etc/rabbitmq/rabbitmq-env.conf node2:/etc/rabbitmq/
scp /etc/rabbitmq/rabbitmq-env.conf node3:/etc/rabbitmq/
# Edit the file on each node to set the correct IP

Step 6: Enable the RabbitMQ management web UI

# List available plugins
/usr/lib/rabbitmq/bin/rabbitmq-plugins list
# Enable management plugin
/usr/lib/rabbitmq/bin/rabbitmq-plugins enable rabbitmq_management mochiweb webmachine rabbitmq_web_dispatch amqp_client rabbitmq_management_agent
# or simply
rabbitmq-plugins enable rabbitmq_management
systemctl restart rabbitmq-server.service
systemctl status rabbitmq-server.service

Step 7: Distribute the .erlang.cookie file from node1 to the other nodes

rabbitmqctl status
scp /var/lib/rabbitmq/.erlang.cookie node2:/var/lib/rabbitmq/.erlang.cookie
scp /var/lib/rabbitmq/.erlang.cookie node3:/var/lib/rabbitmq/.erlang.cookie

Step 8: On node2 and node3, stop the application and join the cluster as RAM nodes, then restart

systemctl restart rabbitmq-server.service
rabbitmqctl stop_app
rabbitmqctl join_cluster --ram rabbit@node1
rabbitmqctl start_app

Step 9: Verify cluster status rabbitmqctl cluster_status Step 10: Access the management UI at

http://192.168.137.138:15672

Other Command Operations

Change default guest password to admin

rabbitmqctl change_password guest admin

Add an administrator user

rabbitmqctl add_user mqadmin mqadmin
rabbitmqctl set_user_tags mqadmin administrator
rabbitmqctl set_permissions -p / mqadmin ".*" ".*" ".*"

Change node type (disc or ram)

rabbitmqctl stop_app
rabbitmqctl change_cluster_node_type disc   # or ram
rabbitmqctl start_app

Remove a node from the cluster or reset a node

rabbitmqctl stop_app
rabbitmqctl reset
rabbitmqctl start_app
rabbitmqctl cluster_status

Forget a specific node from the cluster

rabbitmqctl forget_cluster_node rabbit@node3
rabbitmqctl reset
rabbitmqctl start_app
rabbitmqctl cluster_status

Official rabbitmqctl documentation

https://www.rabbitmq.com/rabbitmqctl.8.html