After creating an RDS for MySQL read-only instance, which of the following CAN NOT be performed by the read-only instance in RDS management console?

To meet business requirements, a user requires that the backend server of an SLB instance include a primary ECS instance and a secondary ECS instance. When the primary instance is working properly, the traffic is only forwarded to the primary ECS, when the primary instance is down, traffic is switched to the standby instance. In this case, you can create an active/standby server group on the backend of the SLB instance Which kind of listener supports this feature? (Number of correct answers: 2)

Compared with traditional physical servers, upgrading an ECS instance is much easier. Which of the following statements about upgrading an ECS instance is false?

Auto Scaling can automatically adjust the number of ECS instances based on user-defined scaling rules to meet service needs. If a user cannot predict service changes or does not have enough history data, he/she can still use dynamic scaling mode to automatically add/remove ECS instances based on certain CloudMonitor performance metrics (such as the CPU utilization rate)

You need to create a new ECS instance for a 10-data test. Which of the following billing methods is most cost-effective?