Auto Scaling is a management service that can automatically adjust elastic computing resources based on your business needs and policies. Which of the following application scenarios are suitable for Auto Scaling? (Choose three.)
Correct Answer: A,B,C
Explanation Alibaba Cloud Server Load Balancer (SLB) is a service that distributes network traffic across multiple ECS instances to improve the service capabilities of applications. SLB supports the following protocols for the listener configuration: HTTP: Hypertext Transfer Protocol, a stateless application-layer protocol that is used to transfer web pages and other resources over the internet. HTTPS: Hypertext Transfer Protocol Secure, an extension of HTTP that uses SSL/TLS encryption to provide secure communication between the client and the server. TCP: Transmission Control Protocol, a reliable, connection-oriented transport-layer protocol that provides reliable data delivery and error recovery. UDP: User Datagram Protocol, a connectionless transport-layer protocol that provides fast and efficient data transmission without guaranteeing reliability or order. SLB does not support the following protocols: MPLS: Multiprotocol Label Switching, a data-carrying technique that uses labels to forward packets across a network. MQTT: Message Queuing Telemetry Transport, a lightweight publish/subscribe messaging protocol that is designed for constrained devices and low-bandwidth networks. References: Alibaba Cloud Server Load Balancer ACA Cloud Computing Certification Exam Preparation Course Alibaba Cloud Computing Exam Question 2022
Question 27
You built an online shop using Alibaba Cloud services (ECS, RDS, ...etc.) and very soon you'll have a campaign that every customer that invites 3 friends will get a 50% off coupon. To avoid HTTP flood attacks and ensure only genuine customers (not bots) joining the event, which security product should you choose?
Correct Answer: C
Explanation After adding your website to the WAF protection list, you can enable HTTP Flood protection and select an appropriate protection mode for the website
Question 28
Auto Scaling can automatically remove unhealthy ECS instances from the scaling group (this feature is called Elastic Self-Health). Yet, after removal, the user has to manually add equivalent amount of new ECS instances back to the scaling group.
Correct Answer: A
Question 29
Alibaba Cloud provides anti-DDoS products of different levels. If the service availability needs to be kept at 99.9% or higher under DDoS attacks, which of the following is the MOST suitable product?
Correct Answer: D
Explanation Alibaba Cloud provides anti-DDoS products of different levels to protect your applications and data from DDoS attacks. Among them, Anti-DDoS Service Pro is the most suitable product for ensuring high service availability under DDoS attacks. Anti-DDoS Service Pro is a proxy-based mitigation service that diverts network traffic to the Alibaba Cloud global anti-DDoS network through DNS resolution, mitigates volumetric DDoS attacks and resource exhaustion DDoS attacks, and ensures the stability and availability of your origin servers1. Anti-DDoS Service Pro provides the following features and benefits2: Over 10 Tbit/s mitigation capacity: Anti-DDoS Service Pro can defend against large-scale DDoS attacks at the Tbit/s level and ensure high service availability. AI-enabled for mitigating sophisticated attacks: Anti-DDoS Service Pro can automatically detect and mitigate sophisticated DDoS attacks, such as HTTP flood, HTTPS flood, and DNS flood, and quickly adjust protection policies based on the attack characteristics. Hiding origin server IPs: Anti-DDoS Service Pro can hide the IP addresses of your origin servers and prevent attackers from bypassing the proxy and directly attacking your origin servers. Multiple protection modes: Anti-DDoS Service Pro supports normal protection mode, emergency protection mode, and always-on protection mode, which can be switched based on your business needs and risk levels. Comprehensive security reports: Anti-DDoS Service Pro provides comprehensive security reports that display the attack details, protection status, and traffic statistics of your protected domains. References: 1: Anti-DDoS: Intelligent DDoS Protection Service - Alibaba Cloud2: Anti-DDoS Pro and Anti-DDoS Premium features - Anti-DDoS Pro and Anti-DDoS Premium - Alibaba Cloud Documentation Center.
Question 30
Company A builds a sales management platform based on Alibaba Cloud services, using 3 ECS instances. One of the ECS instance has MySQL installed as the database server of the platform, the other two are used as WEB servers. After some time, due to the rapid increase of employees and sales analysis requests, the performance of the platform is challenged in terms of response time. Through CloudMonitor, it is found that the average CPU usage reaches 70% for the two WEB server ECS instances and the database load reaches 75% for the database server ECS instance. In this situation, company A may choose which Alibaba Cloud services to improve the performance. (Choose two.)
Correct Answer: A,C
Explanation A and C are the correct answers because they can improve the performance of the platform by reducing the load on the ECS instances and the database server. A is correct because using CDN can accelerate the delivery of static content such as CSS and JavaScript files, which can reduce the bandwidth consumption and latency of the ECS instances. CDN can also cache the content in edge nodes closer to the end users, which can improve the user experience and response time of the platform1 C is correct because using RDS can replace the existing self-built database, which can provide better database performance, reliability, security, and scalability. RDS can also handle the backup, recovery, monitoring, and maintenance of the database, which can reduce the management overhead and cost of the platform. Moreover, creating RDS read-only instances can handle read-only requests, which can reduce the workload on the master RDS instance and improve the database availability and performance23 References: 1: CDN Overview 2: RDS Overview 3: RDS Read-only Instances
