Overview #
This article guides you through updating and upgrading the RELIANOID Load Balancer Cluster with zero downtime. Depending on the configured services, you may experience minimal or no downtime. User sessions might be affected based on the type of connections or sessions within the services.
Without a configured cluster, downtime could increase to a maximum of one minute in the worst-case scenario.
Environment #
The environment described in this scenario is applicable to both standalone and clustered RELIANOID load balancers. For standalone configurations, the load balancer operates independently, managing traffic and ensuring reliable performance for connected clients. However, the true strength of the RELIANOID load balancers is demonstrated in a clustered setup, where multiple nodes work in unison to balance the load, optimize resource utilization, and enhance fault tolerance.
In a clustered configuration, both load balancer nodes collaborate to deliver full high availability, ensuring that client connectivity remains seamless and uninterrupted. This redundancy means that even if one node encounters an issue, the other can seamlessly take over, maintaining continuous service. This setup is crucial for businesses that require consistent uptime and reliability, as it prevents disruptions and maintains a smooth user experience.
Requirements #
To upgrade your RELIANOID load balancer, you must meet one of two requirements. First, ensure that your system has internet connectivity to access the official RELIANOID repository directly. This allows for seamless downloading and installation of updates, ensuring your load balancer remains current with the latest features and security patches.
Alternatively, if internet connectivity is not available or preferred, you can download the offline update ISO from the RELIANOID Support Portal in the Knowledge section > Enterprise Edition > Binaries > RELIANOID 6 Offline update packages . Once downloaded, you need to upload the ISO file to your load balancer, specifically to the directory path /usr/local/relianoid/updates. This method provides flexibility for environments with strict network policies or limited internet access, allowing you to manually manage and apply updates as needed.
Minor and Patched versions update Procedure #
Starting with RELIANOID 6.0.0, updates to minor and patched versions are managed using the checkupgrades tool. Please follow the following simple steps to proceed with an update of your load balancers:
1. Begin by creating a backup or snapshot of both nodes in the cluster. This precaution allows you to revert any changes if necessary, ensuring the stability and integrity of your system.
2. Connect to the backup node and put it into maintenance mode. Run the “checkupgrades” command to download new packages, followed by “checkupgrades -i” to install the updates.
[maintenance] root@noid-ee-02:~# checkupgrades [maintenance] root@noid-ee-02:~# checkupgrades -i
3. Connect to the master node and put it into maintenance mode. Then, switch back to the backup node and take it out of maintenance mode, making it available. This is the only step that requires a minimum downtime in the worst case.
4. On the master node, run “checkupgrades” to download new packages and “checkupgrades -i” to install the updates. Finally, take the master node out of maintenance mode to enable it.
[maintenance] root@noid-ee-01:~# checkupgrades [maintenance] root@noid-ee-01:~# checkupgrades -i
Major versions upgrade Procedure #
Starting with RELIANOID 6.2.34, upgrades to major versions (ex. from Enterprise Edition 6.2 to 8.0) are managed using the checkupgrades tool. Please follow the following simple steps to proceed with an upgrade of your load balancers:
1. Begin by creating a snapshot of both nodes in the cluster. This precaution allows you to revert any changes if necessary, ensuring the stability and integrity of your system.
2. Connect to the backup node and put it into maintenance mode. Run the “checkupgrades -U” command to configure the new major repository version and proceed with the upgrade of the system.
[maintenance] root@noid-ee-02:~# checkupgrades -U
Then, reboot the node.
3. Connect to the master node and put it into maintenance mode. Then, switch back to the backup node and take it out of maintenance mode, making it available. This is the only step that requires a minimum downtime in the worst case.
4. On the master node, run “checkupgrades -U” to configure the new major repository version and proceed with the upgrade of the system. Finally, take the master node out of maintenance mode to enable it.
[maintenance] root@noid-ee-01:~# checkupgrades -U
Then, reboot the node.
Final considerations #
After completing the minor update or major upgrade process, disable maintenance mode on both nodes. Verify which node is designated as MASTER and which as BACKUP to ensure you manage the system through the MASTER node, this could take some seconds or few minutes while the nodes negotiate the clustering roles and setting up all the services. Finally, check the cluster service status by navigating to System > Cluster.
Enjoy your just updated RELIANOID without downtime!
