The cloud monitoring feature of Server Load Balancer (SLB) is scheduled to be optimized in different regions. The optimization improves user experience and allows you to monitor more specific resources.
You can create alert rules for the default listener of an SLB instance and for the URL of a forwarding rule.
If you have created alert rules to monitor the number of healthy Elastic Compute Service (ECS) instances or the number of unhealthy ECS instances, the health check data of the default listener no longer contains the health check data of forwarding rules after the optimization. If you want to monitor health checks of forwarding rules, you can create different alert rules based on forwarding rules. For more information, see Set alert rules in the Cloud Monitor console.
The optimization only modifies the reporting logic of health checks and does not affect the forwarding of your business traffic. If false positives are generated due to the optimization, you can modify the alert configurations based on the actual scenario. For more information, see Set alert rules in the Cloud Monitor console.