RabbitMQ is an open source message-broker software that originally implements the AMQP (Advanced Message Queuing Protocol) protocol, and while it has been developed and extended in order to support other protocols such as STOMP (Streaming Text Oriented Messaging Protocol) and MQTT (Message Queuing Telemetry Transport).
RabbitMQ is the message-queueing software that offers support for sending and receiving messages between distributed systems, applications, and services. It’s written with the Erlang programming language and supports client interfaces and libraries for all major programming languages including Python, NodeJS, Java, PHP etc.
In this tutorial, I will show you step-by-step how to set up the RabbitMQ Cluster on a CentOS 7 Server. We will set up the RabbitMQ Cluster using Three CentOS servers, enable the RabbitMQ Management, and Setup the HA policy for all nodes.
Prerequisites
- 3 or more CentOS 7 Server
- 10.0.15.21 node01
- 10.0.15.22 node02
- 10.0.15.23 node03
- Root privileges
What we will do?
- Setup Hosts File
- Install RabbitMQ Server
- Enable RabbitMQ Management Plugins
- Configure Firewalld
- Setup RabbitMQ Cluster
- Configure a New Admin User
- Setup RabbitMQ Queue Mirroring
- Testing
Step 1 – Setup Hosts File
In this step, we will edit the ‘/etc/hosts’ file on all servers and mapping each server IP address as a hostname.
Edit the ‘/etc/hosts’ file using vim editor.
sudo vim /etc/hosts
Now paste the following configuration there.
10.0.15.21 node01 10.0.15.22 node02 10.0.15.23 node03
Save and exit.
Step 2 – Install RabbitMQ Server
In this step, we will install the RabbitMQ Server packages from the EPEL (Extra Packages for Enterprise Linux) repository.
Add the EPEL repository to the CentOS 7 system.
sudo yum -y install epel-release
Now install RabbitMQ Server to all nodes ‘node01’, ‘node02’, and ‘node03’ using the yum command below.
sudo yum -y install rabbitmq-server
And after the installation is complete, start the RabbitMQ service and enable it to launch everytime at system boot.
sudo systemctl start rabbitmq-server
sudo systemctl enable rabbitmq-server
The RabbitMQ Server has been installed on all node cluster CentOS 7.
Step 3 – Enable RabbitMQ Management Plugins
In this step, we will enable RabbitMQ management plugins. It’s an interface that allows you to monitor and handle RabbitMQ server from the web browser, running on the default TCP port ‘15672’.
Enable the RabbitMQ management plugins by running the command below.
sudo rabbitmq-plugins enable rabbitmq_management
Make sure there is no error, then restart the RabbitMQ service.
sudo systemctl restart rabbitmq-server
And the RabbitMQ Management has been enabled.
Step 4 – Configure CentOS Firewalld
In this tutorial, we will enable the CentOS firewalld service, so we need to open the port that’s used by the RabbitMQ server.
We will open the port that uses the RabbitMQ server ‘5672’, the port for RabbitMQ management ‘15672’, and ports for the RabbitMQ cluster ‘4369, 25672’.
Run the following firewalld commands.
sudo firewall-cmd –add-port=15672/tcp –permanent
sudo firewall-cmd –add-port=5672/tcp –permanent
sudo firewall-cmd –add-port={4369/tcp,25672/tcp} –permanent
Now reload firewalld and check all opened ports on the list.
sudo firewall-cmd –reload
sudo firewall-cmd –list-all
The CentOS firewalld configuration has been completed, and we’re ready to set up the RabbitMQ Cluster.
Step 5 – Set up RabbitMQ Cluster
In order to setup the RabbitMQ cluster, we need to make sure the ‘.erlang.cookie’ file is same on all nodes. We will copy the ‘.erlang.cookie’ file in the ‘/var/lib/rabbitmq’ directory from ‘node01’ to other node ‘node02’ and ‘node03’.
Copy the ‘.erlang.cookie’ file using scp commands from the ‘node01’.
scp /var/lib/rabbitmq/.erlang.cookie [email protected]:/var/lib/rabbitmq/
scp /var/lib/rabbitmq/.erlang.cookie [email protected]:/var/lib/rabbitmq/
Make sure there is no error on both servers.
Next, we need to setup ‘node02’ and ‘node03’ to join the cluster ‘node01’.
Run all commands below on the ‘node02’ and ‘node03’ servers.
Restart the RabbitMQ service and stop the app.
sudo systemctl restart rabbitmq-server
sudo rabbitmqctl stop_app
Now let RabbitMQ server on both nodes join the cluster on ‘node01’, then start the app.
sudo rabbitmqctl join_cluster [email protected]
sudo rabbitmqctl start_app
After it’s complete, check the RabbitMQ cluster status.
sudo rabbitmqctl cluster_status
And you will get the results as shown below.
On the ‘node02’.
On the ‘node03’.
The RabbitMQ Cluster has been created, with node01, node02, and node03 as members.
Step 6 – Create a New Administrator User
In this tutorial, we will create a new admin user for our RabbitMQ server and delete the default ‘guest’ user. We will be creating a new user from ‘node01’, and it will be automatically replicated to all nodes on the cluster.
Add a new user named ‘hakase’ with password ‘[email protected]’.
sudo rabbitmqctl add_user hakase [email protected]
Setup the ‘hakase’ user as an administrator.
sudo rabbitmqctl set_user_tags hakase administrator
And grant the ‘hakase’ user permission to modify, write, and read all vhosts.
sudo rabbitmqctl set_permissions -p / hakase “.*” “.*” “.*”
Now delete the default ‘guest’ user.
sudo rabbitmqctl delete_user guest
And check all available users.
sudo rabbitmqctl list_users
And you will get the result as shown below.
A new RabbitMQ user has been created, and the default ‘guest’ user is deleted.
Step 7 – RabbitMQ Setup Queue Mirroring
This setup is must, we need to configure the ‘ha policy’ cluster for queue mirroring and replication to all cluster nodes. If the node that hosts queue master fails, the oldest mirror will be promoted to the new master as long as it synchronized, depends on the ‘ha-mode’ and ‘ha-params’ policies.
Following are some example about the RabbitMQ ha policies.
Setup ha policy named ‘ha-all’ which all queues on the RabbitMQ cluster will be mirroring to all nodes on the cluster.
sudo rabbitmqctl set_policy ha-all “.*” ‘{“ha-mode”:”all”}’
Setup ha policy named ‘ha-two’ which all queue name start with ‘two.’ will be mirroring to the two nodes on the cluster.
sudo rabbitmqctl set_policy ha-two “^two.”
‘{“ha-mode”:”exactly”,”ha-params”:2,”ha-sync-mode”:”automatic”}’
Setup ha policy named ‘ha-nodes’ which all queue name start with ‘nodes.’ will be mirroring to two specific nodes ‘node02’ and ‘node03’ on the cluster.
sudo rabbitmqctl set_policy ha-nodes “^nodes.”
‘{“ha-mode”:”nodes”,”ha-params”:[“[email protected]”, “[email protected]”]}’
Now check all available policies using the command below.
sudo rabbitmqctl list_policies;
And if you want to remove the policy, use the following command.
sudo rabbitmqctl clear_policy ha-two
Step 8 – Testing
Open your web browser and type the IP address of the node with port ‘15672’.
http://10.0.15.21:15672/
Type the username ‘hakase’ with password ‘[email protected]’.
And you will get the RabbitMQ admin dashboard as below.
All cluster nodes status is up and running.
Now click on the ‘Admin’ tab menu, and click the ‘Users’ menu on the side.
And you will get the hakase user on the list.
Now click on the ‘Admin’ tab menu, and click the ‘Policies’ menu on the side.
And you will get all RabbitMQ ha policies we’ve created.
The installation and configuration of RabbitMQ Cluster on CentOS 7 server has been completed successfully.
Reference
About Muhammad Arul
Muhammad Arul is a freelance system administrator and technical writer. He is working with Linux Environments for more than 5 years, an Open Source enthusiast and highly motivated on Linux installation and troubleshooting. Mostly working with RedHat/CentOS Linux and Ubuntu/Debian, Nginx and Apache web server, Proxmox, Zimbra Administration, and Website Optimization. Currently learning about OpenStack and Container Technology.