What should be done to prevent traffic from reaching a backend server during maintenance on OCI?

To prevent traffic from reaching a backend server during maintenance on Oracle Cloud Infrastructure (OCI), the best approach is to drain connections to the server and mark it as offline. This method allows for a graceful removal of the server from active traffic without abruptly cutting off connections that are currently in progress. By draining connections, existing users can complete their activities, ensuring a smoother user experience.

Marking the server as offline in the load balancer configuration informs the load balancer to stop sending new requests to the server, while still allowing any ongoing requests to complete. This practice aligns with standard operational procedures, which prioritize service continuity and user satisfaction during maintenance windows.

On the other hand, completely stopping the load balancer would affect all backend servers under the load balancer’s management, potentially disrupting service to users who might otherwise be directed to functional servers. Removing the server from the backend set could cause service disruptions as well, especially if done without prior notice, as this might impact any ongoing sessions. Editing the security list to block all traffic to the server would be a more drastic step and could lead to unwanted service interruptions, as it would prevent any traffic from ever reaching the server, not just during maintenance.

Thus, draining connections and marking the server offline ensure maintenance can