This image shows an Oracle Cloud Infrastructure region that includes Oracle Cloud Infrastructure Object Storage, Oracle Cloud Infrastructure Monitoring, and Oracle Cloud Infrastructure Notifications services. The region includes a single availability domain and a virtual cloud network (VCN) with an internet gateway and four regional subnets. A user group lies outside the Oracle Cloud Infrastructure region.

This image shows the following work flow:

1. User requests come into the load balancer subnet through the internet gateway. The load balancer subnet manages traffic to two other subnets each of which contains a virtual machine (VM) functioning as a load balancer back-end server.
2. Server status information passes from the load balancer subnet to the regional monitoring service.
3. Alarm conditions pass from the regional monitoring service to the regional notification service.
4. Alarm notifications are broadcast to subscribers, including the subnet in which the functions are deployed.
5. Functions determine which rule set to add to or remove from the load balancer.
6. The load balancer uses the URL specified in the rule set to call the custom error page in object storage.
7. The load balancer retrieves the custom error page.
8. The load balancer provides the custom error page response to the user.