CloudLinux’s Gradual Rollout System (GRS) is a feature designed to enable smooth updates and gradual rollouts of software versions, patches, or new configurations across a server environment. It ensures that new changes are tested on a subset of users first, allowing for better control over deployment and minimizing risks associated with issues arising from a mass rollout.

The system is used to manage the rollout of new updates and configurations on servers using CloudLinux OS and is typically applied to major updates, system patches, security patches, and kernel upgrades.

Key Features

1. Incremental Rollout: The CloudLinux Gradual Rollout System allows administrators to gradually deploy changes across servers in stages rather than pushing an update to all systems at once. This minimizes the impact of potential issues.

2. Controlled Testing Environment: The feature can be used to test updates on a small percentage of the production servers before expanding to the entire environment. This allows for a controlled testing phase, which can help catch any issues early in the process.

3. Configurable Rollout Pace: You can configure the rate at which the updates are rolled out, including the percentage of servers being affected at each stage. The rollout pace can be adjusted according to the criticality of the update and the performance of the systems involved.

4. Rollback Capabilities: If an update or configuration change causes issues, the system allows administrators to roll back to the previous version seamlessly. This helps minimize downtime and ensures system stability.

5. Monitoring and Alerts: The system allows administrators to monitor the progress of the rollout in real-time and receive alerts if something goes wrong during the process. Logs and system information are provided to help diagnose issues quickly.

6. Granular Control Over Which Systems Are Affected: It allows for grouping systems based on parameters such as geographical location, hardware specifications, or client preference. This gives users granular control over which servers get the updates first.

7. Automated or Manual Rollout: The system can either automatically deploy updates at a set pace or be manually controlled by system administrators, depending on the preferences of the team.

Benefits

• Reduced Risk: Gradual rollouts reduce the risk of widespread failures and allow for better control over potential issues. By testing updates on a smaller set of servers, administrators can avoid or address problems before they affect the entire infrastructure.

• Enhanced Stability: With the ability to test in stages, the stability of the overall system is maintained, and any adverse effects from an update can be minimized. This is especially important in mission-critical environments.

• Customization: Different environments may need different rollout strategies. The CloudLinux Gradual Rollout System is flexible and allows for tailored rollout plans based on unique server configurations and requirements.

• Cost-Effective: By reducing the risk of system failure, the costs associated with downtime, performance degradation, or the need for emergency patches are minimized.

How It Works

1. Preparation:

   • The system administrator selects the update or configuration to be rolled out.
   • Define the percentage of servers or the specific servers that should first receive the changes.
   • Set parameters such as the pace of the rollout, monitoring tools, and rollback procedures.

2. Gradual Rollout:

   • The update is deployed in increments, beginning with a small subset of the servers.
   • CloudLinux tracks the performance and behavior of the affected servers. If any issues arise, the system automatically triggers alerts or stops the rollout for that group.
   • As the update proceeds smoothly, the percentage of servers receiving the change is gradually increased.

3. Monitoring:

   • Throughout the rollout process, system administrators have access to logs and performance reports that help them assess the success of the update.
   • Alerts are triggered if any issues are detected, allowing immediate action, such as stopping the rollout or rolling back to the previous version.

4. Finalization:

   • Once the update has been successfully rolled out to all intended systems without any issues, the process is complete.
   • The system maintains detailed logs for auditing and compliance purposes.

Use Cases

1. CloudLinux Kernel Updates: Kernel updates are crucial for system security and performance. Using the Gradual Rollout System, administrators can ensure that kernel updates do not disrupt the environment.

2. Security Patches: For critical security patches, rolling out the update gradually ensures that no system is left vulnerable for too long and that any issues are caught early.

3. Configuration Changes: Changes in system configurations (e.g., PHP versions, web server settings) can be deployed gradually to test their impact on server performance and user traffic.

4. New Features: When new CloudLinux features are introduced (e.g., LVE Manager updates), they can be rolled out incrementally to avoid destabilizing the entire hosting environment.