Free Alibaba Cloud ACP-Cloud1 Practice Exam with Questions & Answers | Set: 2

Intelligent DNS resolution is a feature of Alibaba Cloud DNS that allows users to configure different IP addresses for the same domain name based on the geographic locations or ISPs of the visitors. This way, visitors can access the nearest or optimal server for better performance and availability. Intelligent DNS resolution does not support web page content caching, which is a function of Alibaba Cloud CDN. Alibaba Cloud CDN is a distributed network that delivers content from the origin server to the edge nodes closest to the end users, reducing the network latency and bandwidth consumption. Alibaba Cloud CDN caches the static content of the web pages, such as images, CSS, and JavaScript files, on the edge nodes, so that the users can access them faster and reduce the load on the origin server. A user will receive data from the cache in the first-time access, and then will be updated from the origin site in subsequent requests based on the cache expiration time.

References:

1: Intelligent DNS resolution - Alibaba Cloud DNS - Alibaba Cloud Documentation Center

4: Alibaba Cloud Content Delivery Network (CDN) performs content acceleration with the support of intelligent DNS resolution The following function_________is NOT included in intelligent DNS resolution.

5: Alibaba Cloud DNS:Alibaba Cloud line for intelligent DNS resolution (September 16, 2020) - Alibaba Cloud Documentation Center

Using a single PUT upload through the console, the maximum file size is 5GB. For larger files, multipart uploading should be used, which allows uploads up to 5TB by splitting files into smaller parts.

To enable Internet access for ECS instances in a VPC, Alibaba Cloud users can use a public SLB with an Internet IP address (Option B) or an SLB with an Elastic IP (EIP) attached (Option C). Both methods allow the SLB instance to receive external requests and forward them to ECS instances within the VPC. Option A is incorrect because it would require a more complex setup without direct Internet access. Option D is incorrect as SLB does not support directly mounting servers from an on-premises data center.

When using Alibaba Cloud SLB, you can set different weights for backend ECS instances. The higher the weight of a backend ECS instance, the more load will be assigned to it. However, the load distribution is not based on the absolute value of the weight, but on the proportion of the weight in the total weight of all healthy backend ECS instances. For example, if there are two healthy backend ECS instances with weights of 100 and 200 respectively, the first instance will receive 33.3% of the load, and the second instance will receive 66.7% of the load. Therefore, to determine the load distribution of the 5 ECS instances in the question, we need to know the weight settings of the remaining 4 ECS instances. Without this information, we cannot tell what would happen. The other options are incorrect because they are based on wrong assumptions or misunderstandings of the SLB weight setting mechanism. 

The port 3306 is the default port on which MySQL is usually configured. This port is used by MySQL clients and applications to connect to the MySQL server. If you are using any other port, you should allow traffic to that specific port instead. Alibaba Cloud RDS for MySQL also uses this port by default, unless you specify a different port when creating the RDS instance. You can view and modify the port number of your RDS instance in the RDS console. References: How to configure an Amazon RDS environment for MySQL, Connecting to a DB instance running the MySQL database engine, [Create an ApsaraDB RDS for MySQL instance]

Pay-As-You-Go is a billing method that allows you to pay for resources after you use them. You are billed based on the actual usage of resources, such as the number of hours that an ECS instance runs or the amount of data that is transferred. Pay-As-You-Go is suitable for scenarios where the demand for resources is unpredictable, flexible, or short-term1. Pay-As-You-Go has the following advantages for the startup video streaming company:

No upfront payment: The company does not need to pay any fees in advance when they purchase ECS instances. They only pay for the resources that they actually use, which can help them save costs and optimize their cash flow1.

Flexible scaling: The company can easily scale up or down their ECS instances based on the actual demand for their service. They can add more ECS instances during peak hours or events, such as Christmas, and release them when the demand drops. They can also change the configurations of their ECS instances at any time, such as upgrading the CPU, memory, or bandwidth1.

No long-term commitment: The company does not need to commit to a long-term contract or subscription when they use Pay-As-You-Go. They can release their ECS instances at any time without incurring any penalties or fees. They can also switch to other billing methods, such as Subscription or Savings Plan, if their business needs change1.

The other billing methods of ECS are not as suitable as Pay-As-You-Go for the company’s scenario, for the following reasons:

Pay-As-You-Go with Reserved Instances: Reserved Instances are a type of discount coupon that can be used to deduct a portion of the fees incurred by Pay-As-You-Go instances that match the attributes of the Reserved Instances, such as region, zone, instance type, and operating system2. Reserved Instances require upfront payment and have a fixed term of one year or three years. They are suitable for scenarios where the demand for resources is stable and predictable, and where the user wants to enjoy lower prices than Pay-As-You-Go2. However, for the company’s scenario, Reserved Instances are not a good option, because they do not need to purchase a large number of ECS instances for a long period of time, and they want to have more flexibility and scalability in their resource management.

Subscription with Reserved Instances: Subscription is a billing method that allows you to pay for resources in advance for a specific period of time, such as one month, one year, or three years. You are billed based on the specifications and duration of the resources that you purchase, regardless of whether you use them or not. Subscription is suitable for scenarios where the demand for resources is stable and long-term, and where the user wants to enjoy lower prices than Pay-As-You-Go3. Subscription with Reserved Instances can further reduce the cost of Subscription instances by applying the Reserved Instances discounts to them2. However, for the company’s scenario, Subscription with Reserved Instances are not a good option, because they do not want to pay for resources in advance or commit to a long-term contract, and they want to have more flexibility and scalability in their resource management.

Pay-As-You-Go with Savings Plan: Savings Plan is a billing method that allows you to commit to a consistent amount of usage (measured in USD/hour) for a one-year or three-year term, and in exchange, receive a lower price for that usage4. Savings Plan can be applied to any Pay-As-You-Go instances that match the attributes of the Savings Plan, such as region, instance family, or operating system4. Savings Plan is suitable for scenarios where the demand for resources is stable and predictable, and where the user wants to enjoy lower prices than Pay-As-You-Go and more flexibility than Subscription4. However, for the company’s scenario, Savings Plan is not a good option, because they do not want to commit to a consistent amount of usage for a long period of time, and they want to have more flexibility and scalability in their resource management.

References: Pay-As-You-Go - Elastic Compute Service - Alibaba Cloud, Reserved Instances - Elastic Compute Service - Alibaba Cloud, Subscription - Elastic Compute Service - Alibaba Cloud, Savings Plan - Elastic Compute Service - Alibaba Cloud

Alibaba Cloud OSS (Object Storage Service) provides extremely high data reliability, typically around 99.99999999%, due to its multi-replica and distributed architecture, ensuring data durability and resilience against single points of failure (SPOF). OSS is designed to store massive amounts of data with high redundancy, making it a preferred choice for businesses that require high reliability and fault tolerance in cloud storage.

Alibaba Cloud OSS does not charge for data ingress, meaning there are no traffic charges for uploading files to OSS, whether through the management console or Open API. However, traffic charges may apply for data egress, i.e., downloading files from OSS.

 Cloud Firewall is a service that provides centralized protection for your cloud assets and prevents unauthorized access to your servers. Cloud Firewall can monitor and control the inbound and outbound traffic of your servers, and block malicious requests and attacks. Cloud Firewall can also detect and prevent brute force password cracking attempts by using intelligent algorithms and threat intelligence. Therefore, option A is the correct answer. References: What is Cloud Firewall?, Protect servers from brute force attacks

In Alibaba Cloud RDS, read-only instances are synchronized from the master instance but do not allow actions such as creating or deleting databases, configuring backup policies, or changing account authorizations. However, you can configure the read-only instance’s whitelist to control access.