Important Alibaba ACA-Cloud1 Exam Questions

Answer: C

Explanation:

A large shopping mall deploys a new video surveillance system. The five-floor building in which the mall is located installed 35 HD cameras to monitor the major exits. The surveillance system is deployed on an ECS instance, which has four 2 TB data disks to store video data.

However, video data grows rapidly and the engineers find that the ECS will run out of storage space within 2 weeks.

In this case, OSS is thought to be the best solution for addressing the storage challenge while ensuring quick access to historical video data when needed. OSS is a cloud-based object storage service that provides massive, secure, low-cost, and highly reliable storage for unstructured data such as images, videos, and documents. OSS can store any amount of data and scale up or down on demand. OSS also supports direct video stream storage capabilities, removing the need for a video segmentation cluster. OSS can be accessed through RESTful APIs, SDKs, or web consoles, and can be integrated with other Alibaba Cloud services such as CDN, ECS, and SLB. OSS provides various storage classes for different data storage scenarios, from hot data storage to cold data storage.For video surveillance data, the Infrequent Access (IA) or Archive storage classes can be used to reduce the storage cost while maintaining high data durability and availability123.Reference:1: Alibaba Cloud Multimedia Solutions | Video Monitoring & Surveillance12: Overview - Object Storage Service - Alibaba Cloud23: OSS Concepts - Alibaba Object Storage Service Course - Cloud Academy

Answer: C

Explanation:

The main purpose of DDoS attack is to make the target server unable to provide service normally, which is one of the network attacks that are most difficult to defend.Comprehensive and Detailed A Distributed Denial-of-Service (DDoS) attack is a malicious attempt to disrupt the normal operation of a target server, service, or network by overwhelming it with a flood of internet traffic from multiple sources1. The main purpose of a DDoS attack is to make the target server unable to provide service normally, which is one of the network attacks that are most difficult to defend.A DDoS attack can cause serious damage to the availability, performance, and reputation of the target server, service, or network, and result in significant financial losses and customer dissatisfaction2.

The other options are not accurate descriptions of a DDoS attack. The main target for a DDoS attack is not the database, but the server, service, or network that hosts the database or other applications. A DDoS attack will not try to crack the password through a large number of attempts, but rather try to exhaust the resources of the target server, service, or network.The purpose of a DDoS attack is not to steal confidential information, but rather to disrupt the normal operation of the target server, service, or network.Reference:1: What is a DDoS Attack?12: Anti-DDoS: Intelligent DDoS Protection Service - Alibaba Cloud2

Answer: C

Explanation:

Web Application Firewall (WAF) is a cloud-based security service that protects web applications from common web attacks, such as SQL injection, cross-site scripting, and HTTP flood. WAF can also filter out malicious requests and bots, and ensure that only legitimate traffic reaches the web servers. WAF can help online shops to avoid HTTP flood attacks and ensure only genuine customers joining the event.

Alibaba Cloud Web Application Firewall

ACA Cloud Computing Certification Exam Preparation Course

Alibaba Cloud Computing Exam Question 2022

After adding your website to the WAF protection list, you can enable HTTP Flood protection and select an appropriate protection mode for the website

Answer: A, D

Explanation:

You can create a custom image for ECS using data disk snapshots or system disk snapshots. A snapshot is a backup of the data on a disk at a specific point in time. You can use snapshots to create custom images, which are copies of the operating system and applications on a disk.You can use custom images to create ECS instances that have the same operating system, applications, and data as the original disk12.

You cannot create a custom image for ECS using CPU snapshots or memory snapshots. These are not valid terms in Alibaba Cloud.CPU and memory are not persistent storage devices, and they do not store the operating system and applications that are required for creating a custom image34.Reference:1: Create a custom image from a snapshot - Alibaba Cloud12: What is a custom image?- Alibaba Cloud23: What is a CPU?- Alibaba Cloud34: What is memory?- Alibaba Cloud4

Answer: B

Explanation:

Your website has oscillating traffic peaks that are difficult to predict in advance. In this scenario, it is recommended to use SLB and Auto Scaling together with ECS. SLB is a service that distributes traffic among multiple ECS instances according to the configured forwarding rules. It can be used to balance the load and improve the service availability and fault tolerance of applications. Auto Scaling is a service that automatically adjusts computing resources based on your volume of user requests. When the demand for computing resources increases, Auto Scaling automatically adds ECS instances to serve additional user requests, or alternatively removes instances in the case of decreased user requests.By using SLB and Auto Scaling together with ECS, you can achieve high scalability and elasticity for your website, and cope with the changing traffic patterns12.Reference:1: ACA Cloud Computing Exam Preparation Course - Alibaba Cloud32: Auto Scaling: Automatically Adjusts Computing Resources - Alibaba Cloud4