Question 1

Alibaba Cloud's object storage (Object Storage Service, OSS for short) can be used to store massive amount of files, but there is still a maximum number of files in a single bucket.

Accepted Answer

While Alibaba Cloud's object storage can store massive amounts of files, there is still a maximum number of files that can be stored in a single bucket. The maximum number varies depending on the region and storage capacity chosen.

Question 2

A company uses Alibaba Cloud SLB and Auto Scaling at the same time, hoping this combination can help save O&M cost and provide a stable and reliable system. However, because they do not have relevant experience, the company's engineers listed some precautions based on their understanding, and turned the list to you for advice. As an expert of Alibaba Cloud, you tell them only _______________ is correct.
A) SLB instances must have Health Check enabled, or they cannot be used together with Auto Scaling
B) All ECS instances under the same SLB instance must be running on the same operating system
C) All backend servers under the same SLB instance must be in the same Scaling Group
D) All backend servers under the same SLB instance must have the same configuration

Accepted Answer

Option A is correct as Health Check is a prerequisite for using SLB and Auto Scaling together, as it helps to ensure that only healthy ECS instances are added to the backend pool. 
The other options are incorrect as they are either not necessary or not relevant to using SLB and Auto Scaling together.

Question 3

Alibaba Cloud CDN can directly accelerate the access to the files stored in OSS and reduce OSS traffic costs.

Accepted Answer

Alibaba Cloud CDN integrates with Alibaba Cloud OSS to provide low-latency, high-throughput, and low-cost data access services. It can directly accelerate the delivery of static content stored in OSS by caching the content on edge servers located in different regions, thereby reducing the origin server load and response time. This leads to improved user experience and reduced OSS traffic costs.

Question 4

Some applications may encounter large traffic fluctuations within a short period. When ECS is used with _______, the number of ECS instances is automatically adjusted based on traffic.
A) Server Load Balancer
B) RDS
C) Auto Scaling
D) OSS

Accepted Answer

Auto Scaling automatically adjusts the number of ECS instances based on traffic fluctuations, allowing the application to scale up or down as needed to meet demand. Server Load Balancer can also help distribute traffic across multiple ECS instances, but it does not automatically adjust the number of instances. RDS and OSS are not relevant to this question as they are database and object storage services, respectively.

Question 5

Company В builds a music download website based on OSS and ECS, and users can download mp3 files after registering for the website. Recently, the public network traffic to the OSS has doubled but the increase of registered users is less than 10%. After in-depth analysis, engineers find that many user download requests are raised from search engine but not the website itself. In this case, which of the following measures is thought to be able to address this issue.
A) Migrates music files from the OSS to the data disks for ECS instances.
B) Changes the website access mode to HTTPS.
C) Limits access sources by configuring "Anti-leech settings" of OSS bucket attributes.
D) Introduce SLB for extra protection.

Accepted Answer

Limiting access sources by configuring "Anti-leech settings" of OSS bucket attributes can prevent unauthorized access to resources and ensure that the website is only accessed through the website itself. This measure can effectively reduce the excessive traffic to the OSS brought by requests from search engines. On the other hand, option A is not recommended as it may increase the load on the ECS instances and reduce the website's performance. Option B is not relevant to this issue as it only provides security for data transmission. Option D may improve the website's availability, but it does not address the specific issue of excessive traffic to OSS.

Question 6

Cloud disks are reliable because they use __________ to provide block-level data storage for ECS instances, ensuring 99.9999999% data reliability.
A) a distributed file management system with 3 redundant copies
B) a file system
C) a double copy distributed system
D) a Linux file system

Accepted Answer

An ECS disk can be used jointly or separately to meet the requirements of different application scenarios. ECS disks are categorized into ephemeral SSD disks and cloud disks. Compared with ephemeral SSD disks, cloud disks are more reliable as they use a triplicate distributed system to provide block-level data storage for ECS instances, ensuring 99.9999999% data reliability.

Question 7

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.

Accepted Answer

Auto Scaling can remove unhealthy ECS instances and this feature is called Elastic Self-Health. However, the user has to manually add new instances back to the scaling group.

Question 8

Server Load Balancer supports health checks for ECS instances and allows user to specify the frequency. If an ECS instance does not qualify the health check, traffic will not be forwarded to that instance, thereby ensuring application availability.

Accepted Answer

The answer of Server Load Balancer supports health checks for...

Question 9

Server Load Balancer can manage sudden spikes in traffic, minimize response time and maintain 99.99% availability of your web application.

Accepted Answer

Manage sudden spikes in traffic, minimize response time and maintain 99.99% availability of your web application with Server Load Balancer.

Question 10

Which of the following statements is true for RDS?
A) Multiple databases can be created in one RDS instance.
B) Databases with the same name are allowed in the same instance.
C) Resources are not shared among the databases in the same RDS instance.
D) None of the above is true.

Accepted Answer

RDS allows you to create multiple databases within a single instance.

Question 11

RDS for MySQL is a PaaS, which means after creating the RDS instance, the user does not need to take care of the underlying OS, runtime environment of software packages. These would be taken care of by Alibaba Cloud.

Accepted Answer

RDS for MySQL is a PaaS offering by Amazon Web Services (AWS), not Alibaba Cloud. AWS manages the underlying infrastructure, including the OS and runtime environment.

Question 12

___________ feature in Server Load Balancer means that it can forward the access requests from a single user to the same ECS instance within a certain period to ensure session continuity.
A) session persistence
B) health check
C) Weighted Round Robin
D) least connections scheduling

Accepted Answer

Session persistence, also known as sticky session or session affinity, allows the Server Load Balancer to route requests from the same user to the same backend server for the duration of the user's session. This ensures session continuity and prevents the loss of session data or progress. Health check, Weighted Round Robin, and least connections scheduling are other features of Server Load Balancer, but they do not specifically address session persistence.

Question 13

Which of the following ECS instance configurations can't be changed if we don't change instance type?
A) Mem size
B) System disk size
C) Data disk size
D) Number of data disk

Accepted Answer

The system disk size can't be changed without changing the instance type, while mem size, data disk size, and number of data disks can be changed independently.

Question 14

Alibaba Cloud Object Storage Service (OSS) is a massive, highly available, secured and cost effective storage service. OSS is superior than self-built storage in all these aspects. Which of the following advantage relates to the high availability of OSS?
A) Availability actually relies on the underlying hardware, which can break down easily. Once the hard disk malfunctions, it can also lead to permanent data loss.
B) Data Reliability is not less than 99.99999999%. Data is backed up automatically with multiple redundant copies.
C) Data has to be backed up by customer manually, which is time-consuming and labor-intensive.
D) The following features are available: Multiple Authentication and Authorization mechanism, Whitelist, Anti-leech URL, and Master-Sub Account

Accepted Answer

The advantage of high availability of OSS is related to data reliability, which is ensured by automatic backups with multiple redundant copies. Option A is incorrect as it describes the risk of hardware failure, which does not relate to high availability. Option C is also incorrect as it describes the manual backup process, which is not relevant to the high availability of OSS. Option D describes security and access control features, which are important but not directly related to high availability.

Question 15

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.)
A) Use content delivery network, CDN, to accelerate the caching of the platform's css, JavaScript files etc.
B) By adding a SLB instance and increase the number of ECS instances to reduce the work load on current ECS instances.
C) Use RDS to replace existing self-built database, in order to obtain better database performance; also creating RDS read-only instances to handle read-only requests, hence reduce the work load on master RDS instance.
D) Import data into OSS to share the storage load of the platform.

Accepted Answer

Option B, adding a SLB instance and increasing the number of ECS instances, can help distribute the workload and improve the platform's performance in terms of response time. 
Option C, using RDS to replace the existing self-built database, can provide better database performance along with read-only instances to handle read-only requests, thereby reducing the workload on the master RDS instance. 
Option A, using CDN to accelerate caching, can improve performance, but it may not be the best choice in this situation where CPU usage and database load are the main concerns. 
Option D, importing data into OSS to share storage load, may not help much in improving performance as storage load is not the main concern in this situation.

Question 16

Alibaba Cloud Object Storage Service (OSS) is a massive, highly available, secured and cost effective storage service. One of the special characteristics of OSS is its superior data reliability, because of its underlying backup technology and policies. Which of the following statement about OSS backup is correct?
A) OSS supports 3 internal data copies, so the data can be manually recovered should there be any problem.
B) Customer has to safeguard their own data. OSS provides various backup interfaces to facilitate offsite backups.
C) OSS leverages RAID0+1 configuration of its underlying physical hard disks. There is no impact even if 2 hard disks were to fail simultaneously.
D) OSS supports 3 internal data copies, no human intervention is required to recover the data when anything goes wrong.

Accepted Answer

Alibaba Cloud OSS provides various backup interfaces, such as data replication across different zones and disaster recovery solutions, for customers to safeguard their own data. While OSS does have underlying backup technology and policies that contribute to its superior data reliability, it is still the responsibility of the customer to ensure their data is properly backed up. Option A and D are incorrect because OSS does not support 3 internal data copies, and human intervention may be required to recover data. Option C is incorrect because OSS does not use a RAID0+1 configuration, and the simultaneous failure of multiple hard disks could impact data availability.

Question 17

Alibaba Cloud provides powerful security services (the same level of security services used to support Alibaba Group double 11 shopping festival). However, you have to pay first before using any of the security services.

Accepted Answer

Alibaba Cloud offers some basic security services for free, but advanced features and additional services may require payment.

Question 18

ECS can be used along with ______ to store static images, videos, and reducing storage fees.
A) OSS
B) Server Load Balancer
C) RDS
D) VPC

Accepted Answer

ECS can be used along with OSS (Object Storage Service) to store static images and videos, which can help reduce storage fees. Using Server Load Balancer and RDS are not relevant to storing static images and videos. VPC (Virtual Private Cloud) is used for networking and security purposes and does not relate to storing static files.

Question 19

In mainland China, the approval requirements for business record filing vary depending on provincial communication management bureaus.

Accepted Answer

Approval requirements for business record filing do vary depending on provincial communication management bureaus in mainland China.

Question 20

You can retrieve data directly from an ECS Image and use it right away.

Accepted Answer

An ECS (Elastic Container Service) Image is a container image that needs to be instantiated as a running container before you can access and use the data or services it provides.

Exam 1: ACA Cloud Computing Certification Exam

Alibaba Cloud's object storage (Object Storage Service, OSS for short) can be used to store massive amount of files, but there is still a maximum number of files in a single bucket.

Alibaba Cloud CDN can directly accelerate the access to the files stored in OSS and reduce OSS traffic costs.

Some applications may encounter large traffic fluctuations within a short period. When ECS is used with _______, the number of ECS instances is automatically adjusted based on traffic.

Cloud disks are reliable because they use __________ to provide block-level data storage for ECS instances, ensuring 99.9999999% data reliability.

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.

Server Load Balancer supports health checks for ECS instances and allows user to specify the frequency. If an ECS instance does not qualify the health check, traffic will not be forwarded to that instance, thereby ensuring application availability.

Server Load Balancer can manage sudden spikes in traffic, minimize response time and maintain 99.99% availability of your web application.

Which of the following statements is true for RDS?

RDS for MySQL is a PaaS, which means after creating the RDS instance, the user does not need to take care of the underlying OS, runtime environment of software packages. These would be taken care of by Alibaba Cloud.

___________ feature in Server Load Balancer means that it can forward the access requests from a single user to the same ECS instance within a certain period to ensure session continuity.

Which of the following ECS instance configurations can't be changed if we don't change instance type?

Alibaba Cloud Object Storage Service (OSS) is a massive, highly available, secured and cost effective storage service. OSS is superior than self-built storage in all these aspects. Which of the following advantage relates to the high availability of OSS?

Alibaba Cloud provides powerful security services (the same level of security services used to support Alibaba Group double 11 shopping festival). However, you have to pay first before using any of the security services.

ECS can be used along with ______ to store static images, videos, and reducing storage fees.

In mainland China, the approval requirements for business record filing vary depending on provincial communication management bureaus.

You can retrieve data directly from an ECS Image and use it right away.