Cloud disks are reliable because they use_________ to provide block-level data storage for ECS instances, ensuring 99.9999999% data reliability.
Answer : A
Cloud disks are reliable because they use adistributed file management system with 3 redundant copiesto provide block-level data storage for ECS instances, ensuring99.9999999% data reliability. This means that the data stored on cloud disks is automatically replicated across three different physical servers in the same zone. If one server fails, the data can still be accessed from the other two servers. Cloud disks also support snapshot backup and recovery, which can help users restore data to a previous point in time in case of accidental deletion or corruption.Reference:Elastic Compute Service (ECS) - Alibaba Cloud Academy, Cloud Disk - Alibaba Cloud Documentation Center
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.
Using a cloud computing service is simple and straightforward. One can choose the instance with desired specification, finish payment and then use it right away. Moreover, the underlying physical machines are managed by cloud service providers and transparent to users.
Answer : A
Using a cloud computing service is simple and straightforward. One can choose the instance with desired specification, finish payment and then use it right away. Moreover, the underlying physical machines are managed by cloud service providers and transparent to users.This is the basic concept of cloud computing, which provides on-demand, scalable, and reliable computing resources and services over the internet12.Reference:1: ACA Cloud Computing Exam Preparation Course - Alibaba Cloud32: What Is Alibaba Cloud Academy Certification?4
When we talk about the 'Elastic' feature for ECS product, we are not talking about .
Answer : D
Elastic Computing Service (ECS) is a cloud computing service that provides scalable, on-demand computing resources for cloud applications. ECS offers elastic computing, elastic storage, and elastic network features to meet different business needs. However, ECS does not provide elastic administration, which means that the management and configuration of ECS resources are not automatically adjusted according to the workload or demand. Users need to manually create, modify, or delete ECS instances, disks, snapshots, security groups, and other resources. Users can also use other Alibaba Cloud services, such as Auto Scaling, Server Load Balancer, and Cloud Monitor, to enhance the elasticity and availability of ECS.
[Alibaba Cloud Elastic Compute Service]
ACA Cloud Computing Certification Exam Preparation Course
Alibaba Cloud ACA-Cloud1 ACA Cloud Computing Certification Exam
www.company.com is a newly launched social portal for exchanging automotive information. The portal is based on PHP, including 10GB of images, and some JavaScripts files. Currently one single ECS instance is used to host all the application content as well as a MySQL database. With the growing number of users, the portal is getting slower to load images or respond to user requests. Moreover, there will be additional 50GB image content uploaded to the portal every week. Which combination of Alibaba Cloud services below can help resolve the storage and performance issue at the same time?
Answer : A
Object Storage Service (OSS) is a cloud storage service that provides secure, cost-effective, and scalable storage for various data types, such as images, videos, and documents. OSS can store large amounts of data and support concurrent access from multiple users. OSS can also integrate with other Alibaba Cloud services, such as Media Transcoding Service (MTS), Server Load Balancer (SLB), and Elastic Compute Service (ECS). By using OSS, the portal can offload the storage and delivery of the image content from the ECS instance, which can improve the performance and availability of the application.
Content Delivery Network (CDN) is a distributed network that delivers content to users based on their geographic locations, the origin servers, and the content delivery policies. CDN can accelerate the delivery of static and dynamic content, such as images, videos, and web pages, by caching the content at edge nodes that are closer to the users. CDN can also reduce the network latency and bandwidth consumption, as well as enhance the security and reliability of the content delivery. By using CDN, the portal can speed up the loading of images and improve the user experience.
Therefore, the combination of OSS and CDN can help resolve the storage and performance issue of the portal at the same time. The other combinations are not as effective or suitable for the portal's scenario. OSS + MTS combination can help with the storage and transcoding of media files, but not with the delivery of images. OSS + RDS combination can help with the storage and management of relational databases, but not with the loading of images. OSS + ECS combination can help with the storage and computing of data, but not with the acceleration of content delivery.
Alibaba Cloud Object Storage Service
Alibaba Cloud Content Delivery Network
ACA Cloud Computing Certification Exam Preparation Course
Which of the following is not the database type supported by RDS?
Answer : D
RDS (Relational Database Service) is a fully managed online database service that supports various database engines, such as MySQL, SQL Server, PostgreSQL, MariaDB, and PPAS (PostgreSQL with Oracle compatibility)1.However, RDS does not support Oracle database, which is a proprietary database system developed by Oracle Corporation2.If you need to use Oracle database on Alibaba Cloud, you can deploy it on an ECS instance or use the Oracle Database Backup Service3.
A customer uses Alibaba Cloud Auto Scaling service and creates a scaling group. He/she sets the ''Minimum number of instances'' to 6 and ''Maximum number of instances'' to 8.
After correctly configuring scaling settings, the customer adds a scaling rule ''Remove 5 ECS instances'', and creates a scheduled task based on this rule.
And then, the customer checks the scaling group and see it already contains 8 valid ECS instances, he/she then enables this scaling group immediately.
How many ECS instances are left in the scaling group when the scheduled task is activated once?
Answer : B
Alibaba Cloud Auto Scaling service allows you to automatically adjust the number of ECS instances in a scaling group based on your business needs and scaling policies.You can set the minimum and maximum number of instances in a scaling group to limit the range of scaling actions1.When you create a scaling rule, you can specify the number of instances to be added or removed, or the expected number of instances after the scaling action2.You can also create a scheduled task to execute a scaling rule at a specified time or periodically3.
In this question, the customer sets the minimum number of instances to 6 and the maximum number of instances to 8 in the scaling group. This means that the scaling group will always have at least 6 instances and at most 8 instances. The customer also adds a scaling rule to remove 5 instances, and creates a scheduled task based on this rule. However, this scaling rule will not be executed if it violates the minimum and maximum limits of the scaling group. Therefore, when the scheduled task is activated once, the scaling group will only remove 2 instances, which is the difference between the current number of instances (8) and the minimum number of instances (6).The remaining number of instances in the scaling group will be 6, which is the correct answer.Reference:1:Create a scaling group - Auto Scaling - Alibaba Cloud Documentation Center2:Create a scaling rule - Auto Scaling - Alibaba Cloud Documentation Center3:Create a scheduled task - Auto Scaling - Alibaba Cloud Documentation Center.
Section: (none)
Explanation
A customer uses Alibaba Cloud Auto Scaling service and creates a scaling group. He/she sets the ''Minimum number of instances'' to 6 and ''Maximum number of instances'' to 8.
After correctly configuring scaling settings, the customer adds a scaling rule ''Adjust to 10 ECS instances'', and creates a scheduled task based on this rule.
And then, the customer checks the scaling group and see it already contains 6 valid ECS instances, he/she then enables this scaling group immediately.
How many ECS instances are left in the scaling group when the scheduled task is activated once?
Answer : B
Alibaba Cloud Auto Scaling service allows you to automatically adjust the number of ECS instances in a scaling group based on your business needs and scaling policies.You can set the minimum and maximum number of instances in a scaling group to limit the range of scaling actions1.When you create a scaling rule, you can specify the number of instances to be added or removed, or the expected number of instances after the scaling action2.You can also create a scheduled task to execute a scaling rule at a specified time or periodically3.
In this question, the customer sets the minimum number of instances to 6 and the maximum number of instances to 8 in the scaling group. This means that the scaling group will always have at least 6 instances and at most 8 instances. The customer also adds a scaling rule to remove 5 instances, and creates a scheduled task based on this rule. However, this scaling rule will not be executed if it violates the minimum and maximum limits of the scaling group. Therefore, when the scheduled task is activated once, the scaling group will only remove 2 instances, which is the difference between the current number of instances (8) and the minimum number of instances (6).The remaining number of instances in the scaling group will be 6, which is the correct answer.Reference:1:Create a scaling group - Auto Scaling - Alibaba Cloud Documentation Center2:Create a scaling rule - Auto Scaling - Alibaba Cloud Documentation Center3:Create a scheduled task - Auto Scaling - Alibaba Cloud Documentation Center.