ACP-Cloud1 Exam Dumps : ACP Cloud Computing Certification

For Layer-4 SLB using TCP, the health check determines ECS instance availability based on the successful completion of a TCP 3-way handshake. This ensures that the backend server is reachable and can accept connections, which is critical for reliable TCP-based load balancing.

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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 ECS documentation1, the recommended instance type for Tomcat is ecs.c5.xlarge, which has 4 vCPUs and 4 GiB of memory. This instance type is suitable for web applications that require high performance and low latency. The recommended instance type for Memcache is ecs.r5.large, which has 2 vCPUs and 16 GiB of memory. This instance type is optimized for memory-intensive applications that require high memory bandwidth and low latency. Therefore, option D is the most recommended configuration for deploying Tomcat and Memcache on two ECS instances. References: Instance type families and Alibaba Cloud Elastic Compute Service Product Introduction