Table of Contents
In OpenStack, RabbitMQ is one of the most important core component. It is used as the message broker to facilitate communication by allowing services to send and receive messages. This is crucial for coordinating activities and passing information between different components of the OpenStack environment.
Introduction
OpenStack consists of various services such as Nova (compute), Neutron (networking), Cinder (block storage), and others. RabbitMQ allows these services to be loosely coupled by decoupling the sender and receiver. Services can produce messages without knowing who or what will consume them, providing flexibility and modularity in the OpenStack architecture
Therefore, RabbitMQ plays a crucial role in OpenStack by providing a reliable and scalable messaging platform. It enhances the overall efficiency, reliability, and performance of the cloud infrastructure by enabling seamless communication and coordination among the various services that make up OpenStack.
In the complex OpenStack deployements RabbitMQ is deployed in a cluster which ensure messages can be distributed among nodes to balance the load. This ensures that no single node becomes a bottleneck, especially in scenarios where there is a high volume of messages being exchanged between OpenStack services.
In our previous articles we have created the whole OpenStack infrastructure the kolla-ansible. Please have a look to the following articles to check out how OpenStack is deployed through Kolla-Ansible.
- Openstack multinode deployment through Kolla-ansible [part 1]
- Kolla Ansible Files & Configurations for Openstack Multinode installation [Part -2]
- Openstack Multinode environment setup and image building through Kolla-ansible [Part 3]
- Openstack Multinode Deployment through Kolla-ansible [part-4]
Problem Statement
As we are proceeding toward more complex environments: Configuration Changes, Scalling requirements, fault recovery, Troubleshooting and Recovery from data corruption are inevitable problems which can occur in the OpenStack Cluster. Therefore redeploying the RabbitMQ OpenStack cluster can help us solving the mentioned problems. In this article we will talk about how to redeploy the RabbitMQ cluster
Quick Solution
Use the following commands to recreate the cluster
Stop rabbitmq service on all the container nodes and make backup.
docker stop rabbitmq
cp -Ra /var/lib/docker/volumes/rabbitmq/_data/mnesia{,.backup$(date +%F)}
rm -rf /var/lib/docker/volumes/rabbitmq/_data/mnesia/
Redeploying RabbitMQ cluster from the management node.
(yoga-venv) [root@kolla-controller1 ~]# kolla-ansible -i /etc/kolla/multinode reconfigure -t rabbitmq
Explaination
Backup
Taking backups is a crucial before moving forward to redeployment because, we will be removing the RabbitMQ files, and backup serve as a safeguard against data loss, backups provide a means to restore data and the service later if nothing works.
Stop RabbitMQ service in all the controller nodes and copy important files
In our setup created in above mentioned articles we have following two controller nodes.
kolla-controller1 kolla-controller2
Use the following commands to stop the RabbitMQ container and copy the files following command copy command will create Backup file in the same directory with mnesia.backup with the current date appended and it will Preserve the original file attributes and timestamps.
docker stop rabbitmq
cp -Ra /var/lib/docker/volumes/rabbitmq/_data/mnesia{,.backup$(date +%F)}
Removing mnesia folder
Removing the Mnesia folder before redeploying the RabbitMQ cluster is often done to ensure a clean and consistent state for the cluster. Mnesia is the built-in distributed database used by RabbitMQ to store metadata, configuration, and other internal data.
rm -rf /var/lib/docker/volumes/rabbitmq/_data/mnesia/
Redeploying RabbitMQ cluster
As we are using the Kolla-ansible to deploy our OpenStack, following command is telling Kolla to reconfigure the RabbitMQ service in the OpenStack deployment based on the configuration specified in /etc/kolla/multinode. This recreate the RabbitMQ containers with clean and consistent state.
kolla-ansible -i /etc/kolla/multinode reconfigure -t rabbitmq
Further steps:
- Monitor Deployment Progress: Monitor the deployment progress and check for any errors or warnings during the redeployment process.
- Verify RabbitMQ Cluster Status: After the redeployment, verify the status of the RabbitMQ cluster to ensure that it is operational and healthy.
- Testing: Conduct thorough testing to ensure that RabbitMQ is functioning correctly within the OpenStack environment.
