ACP-Cloud1 Exam Dumps : ACP Cloud Computing Certification

According to the Alibaba Cloud Academy, Auto Scaling supports three scaling modes: manual mode, scheduled task, and cloud monitor and event-triggered task. Manual mode requires manual intervention to adjust the number of ECS instances, which is not feasible and with minimum operation efforts. Scheduled task allows you to set the time and number of ECS instances to be added or removed in advance, which is suitable for predictable traffic changes. Cloud monitor and event-triggered task allows you to set the monitoring metrics and thresholds for scaling actions, which is suitable for dynamic traffic changes. Healthy check mode is not a scaling mode, but a feature of SLB to ensure the availability of ECS instances behind the load balancer. References: : ACP Cloud Computing Certification Preparation Course - Auto Scaling, : ACP Cloud Computing Certification Preparation Course - Server Load Balancer

 According to the Alibaba Cloud SLB documentation1, SLB provides a health check feature that monitors the availability and performance of the backend servers. If a backend server fails the health check, SLB stops routing requests to it and redirects the traffic to other healthy servers. This way, SLB can improve the system’s availability by eliminating single points of failure (SPOFs). Therefore, option A is a correct statement about SLB.

According to the same documentation1, SLB instances are assigned with public IP addresses or private IP addresses based on the network type. If you delete an SLB instance and create a new one, a new IP address will be allocated to the new instance. You cannot specify or reserve an IP address for an SLB instance. Therefore, option B is also a correct statement about SLB.

Option C is incorrect, because SLB does not require you to install or configure any SLB agent on the backend servers. You only need to add the backend servers to the SLB instance and configure the listener and the server group. SLB will automatically distribute the traffic to the backend servers based on the load balancing algorithm and the health check status2.

Option D is also incorrect, because SLB does not provide a function to automatically synchronize data among backend servers. SLB only handles the network traffic distribution and does not interfere with the data on the backend servers. You need to use other methods or tools to synchronize data among backend servers, such as rsync, lsyncd, or Alibaba Cloud Data Transmission Service (DTS)3.

References: Server Load Balancer:SLB overview, Add backend servers, and Data Transmission Service.

Alibaba Cloud CDN requires a domain name to function, as it uses DNS resolution to direct requests to the nearest edge nodes. CDN cannot directly accelerate an IP address without a domain name, so the statement is false.