If you deploy an e-commerce website on Huawei Cloud, in order to benefit the old customers and prepare for a one-day big sale, what preparations should the operation and maintenance personnel prepare on Huawei Cloud in advance? (Multiple Choice)
A . Use pressure measurement service Cloud Eys of Huawei Cloud to exercise the high-traffic service capability of the website in advance.
B . Add the metrics that need to be viewed in the routine operation and maintenance to the dashboard, to grasp the global situation in real time.
C . Set threshold alarms for key application performance indicators of the website, and automatically notify the operation and maintenance personnel of the alarms.
D . Prepare resources in advance. Set the elastic expansion group to increase capacity as the resource usage increases during the promotion process.
Answer: BCD