Prerequisites
Before starting, ensure all Debian nodes have static IP addresses and hostname resolution (via /etc/hosts or DNS). For example, add entries like 192.168.1.101 node1 and 192.168.1.102 node2 to /etc/hosts on all nodes and run sudo systemctl restart networking to apply changes.
Step 1: Install Erlang (Required Runtime)
RabbitMQ is built with Erlang, so all nodes need a compatible Erlang/OTP version. On Debian, run:
sudo apt-get update
sudo apt-get install -y erlang-base erlang-asn1 erlang-crypto erlang-eldap erlang-ftp erlang-inets erlang-mnesia erlang-os-mon erlang-parsetools erlang-public-key erlang-runtime-tools erlang-snmp erlang-ssl erlang-syntax-tools erlang-tftp erlang-tools erlang-xmerl
Verify installation with erl -version (should show OTP version ≥ 23).
Step 2: Add RabbitMQ Official Repository & Install
For the latest stable version, add RabbitMQ’s official GPG key and repository:
curl -sLf "https://keys.openpgp.org/vks/v1/by-fingerprint/0A9AF2115F4687BD29803A206B73A36E6026DFCA" | sudo gpg --dearmor | sudo tee /usr/share/keyrings/com.rabbitmq.team.gpg > /dev/null
echo "deb [signed-by=/usr/share/keyrings/com.rabbitmq.team.gpg] http://ppa.launchpad.net/rabbitmq/rabbitmq-erlang/ubuntu $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/rabbitmq.list
echo "deb [signed-by=/usr/share/keyrings/com.rabbitmq.team.gpg] http://ppa.launchpad.net/rabbitmq/rabbitmq-server/ubuntu $(lsb_release -cs) main" | sudo tee -a /etc/apt/sources.list.d/rabbitmq.list
sudo apt-get update
sudo apt-get install -y rabbitmq-server
Start the service and enable auto-start:
sudo systemctl start rabbitmq-server
sudo systemctl enable rabbitmq-server
Step 3: Configure Erlang Cookie (Critical for Node Trust)
RabbitMQ uses the .erlang.cookie file (in /var/lib/rabbitmq/) for node authentication. All nodes must have identical cookie files with 400 permissions.
On the primary node (e.g., node1), copy the cookie to other nodes (e.g., node2):
sudo scp /var/lib/rabbitmq/.erlang.cookie user@node2:/var/lib/rabbitmq/
On each secondary node, set correct permissions:
sudo chmod 400 /var/lib/rabbitmq/.erlang.cookie
sudo chown rabbitmq:rabbitmq /var/lib/rabbitmq/.erlang.cookie
Restart RabbitMQ on all nodes to apply changes:
sudo systemctl restart rabbitmq-server
Step 4: Start Cluster Formation
Choose one node as the primary (e.g., node1). On all other nodes, execute these commands to join the cluster:
sudo rabbitmqctl stop_app
sudo rabbitmqctl reset
sudo rabbitmqctl join_cluster rabbit@node1 # Replace 'node1' with primary node's hostname
sudo rabbitmqctl start_app
stop_app: Stops the RabbitMQ application.reset: Clears local node data (only needed for initial cluster setup).join_cluster: Connects to the primary node (specified by rabbit@hostname).start_app: Restarts the application to join the cluster.Step 5: Verify Cluster Status
On any node, run:
sudo rabbitmqctl cluster_status
Expected output shows all joined nodes (e.g., disc for disk-based nodes, ram for in-memory nodes) and their status (running). Example:
Cluster status of node 'rabbit@node1' ...
[{nodes,[{disc,['rabbit@node1','rabbit@node2']}]},
{running_nodes,['rabbit@node2','rabbit@node1']},
{cluster_name,<<"rabbit@node1">>},
{partitions,[]}]
Optional: Enable Management Plugin (Web UI)
For easy monitoring, enable the management plugin on all nodes:
sudo rabbitmq-plugins enable rabbitmq_management
Access the web interface at http://<node-ip>:15672 (default credentials: guest/guest; change these for production).
Optional: Configure Queue Mirroring (High Availability)
To ensure messages survive node failures, set up queue mirroring. On any node, create a policy to mirror all queues to all nodes:
sudo rabbitmqctl set_policy ha-all "^" '{"ha-mode":"all","ha-sync-mode":"automatic"}'
ha-mode":"all": Mirrors queues to all nodes.ha-sync-mode":"automatic": Automatically syncs messages across mirrors.ha-mode":"exactly","ha-params":2) for specific durability needs.Troubleshooting Tips
.erlang.cookie files (permissions: 400, owner: rabbitmq)./etc/hosts).5672 (AMQP), 15672 (management) in your firewall (e.g., sudo ufw allow 5672/tcp; sudo ufw allow 15672/tcp).
