When using Alibaba Cloud SLB, users can enable the health check function If a backend ECS instance A is running abnormally, SLB will isolate it and forward the requests to other ECS instances, and when the backend ECS instance A is back to normal, SLB will again forward requests to it.
Answer : A
When creating an ECS instance in your Alibaba Cloud VPC, you must specify a VSwitch for that instance at the same time. Otherwise, you will not be able to create this ECS instance.
Answer : A
RDS provides whitelist access policies. You can set permitted IP addresses and IP network segments to effectively prevent hackers from attacking the server by port scanning.
Answer : A
When using Alibaba Cloud SLB to forward layer 7 (HTTP) service requests. SLB will replace the IP address in the HTTP header file to forward requests.
Therefore the source IP address that can be seen on the backend ECS instance is the IP address of SLB instead of the clients real IP address.
Answer : A
Alibaba Cloud SLB can distribute user requests to backend ECS instances. These ECS instances must have the same specification (CPU, Memory)
Answer : A
Alibaba Cloud Elastic Compute Service (ECS) instances in different Security Groups will definitely have no way to communicate with each other.
Answer : A
When a customer uses Alibaba Cloud Object Storage Service (OSS) service and finds there exist an amount of Internet downstream traffic, he/she can use Alibaba Cloud Content Delivery Network (CDN) service to reduce the traffic cost.
Because the Internet traffic cost of CDN is lower than that of OSS, moreover, the back-to-source traffic cost from CDN to OSS is also lower than a user access to OSS directly.
Answer : A
