Alibaba ACA-Cloud1 ACA Cloud Computing Associate Exam Practice Test

Answer : A, D

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 : D

D is the correct answer because OSS supports 3 internal data copies, no human intervention is required to recover the data when anything goes wrong. OSS provides high data reliability and durability by storing multiple replicas of data on different devices in the same region. OSS automatically detects and repairs data errors or failures, and ensures data consistency across all replicas.OSS also supports cross-region replication (CRR) to back up data to another region for disaster recovery12

A, B, and C are incorrect answers because they do not reflect the actual backup technology and policies of OSS.

A is incorrect because OSS does not require manual recovery of data, as it automatically handles data errors or failures.

B is incorrect because OSS provides data protection and backup for customers, and customers do not need to safeguard their own data or use offsite backups.

C is incorrect because OSS does not use RAID0+1 configuration of its underlying physical hard disks, but rather uses a distributed storage system that stores multiple replicas of data on different devices.

Answer : B

B is the correct answer because Auto Scaling can automatically remove unhealthy ECS instances from the scaling group, and also automatically add equivalent amount of new ECS instances back to the scaling group. This feature is called Elastic Self-Health, and it can improve the availability and reliability of the scaling group. Elastic Self-Health can be enabled or disabled in the scaling group settings. When Elastic Self-Health is enabled, Auto Scaling monitors the health status of the ECS instances in the scaling group based on the health check results of the Server Load Balancer (SLB) instances that are associated with the scaling group. If an ECS instance is detected as unhealthy by SLB for a specified period of time, Auto Scaling removes the unhealthy ECS instance from the scaling group and releases it.Then, Auto Scaling triggers a scale-out event to add a new ECS instance to the scaling group to maintain the desired capacity12Reference:1:Elastic Self-Health2:Enable or disable Elastic Self-Health

Answer : B

ECS instance filesystem directory operation is not a supported method to create a bucket in OSS. A bucket is a container for objects in OSS, and it is not related to the filesystem of an ECS instance.To create a bucket in OSS, you can use one of the following methods1:

through OSS API/SDK: You can use the OSS API or SDK to call the PutBucket operation to create a bucket.The OSS API and SDK support various programming languages, such as Java, Python, PHP, C#, and Node.js2.

through oss cmd tool: You can use the oss cmd tool, which is a command-line tool based on the OSS SDK for Python, to create a bucket by using the ossutil mb command3.

through cloud console: You can use the Alibaba Cloud console to create a bucket by following the steps in the documentation4.Reference:1:Create buckets - Object Storage Service - Alibaba Cloud Documentation Center2:PutBucket - API Reference| Alibaba Cloud Documentation Center3:Create a bucket - OSSUTIL User Guide| Alibaba Cloud Documentation Center4:Create a bucket - Object Storage Service - Alibaba Cloud Documentation Center.

Answer : D

Auto Scaling is a management service that can automatically adjust elastic computing resources based on your business needs and policies.Auto Scaling supports the following features12:

Elastic Scale-Out: Automatically adds ECS instances to handle increased workloads.

Elastic Scale-In: Automatically removes ECS instances to reduce costs when workloads decrease.

Elastic Self-Health: Automatically replaces unhealthy ECS instances to ensure high availability and reliability.

Scheduled Scaling: Automatically adds or removes ECS instances based on predefined schedules.

Predictive Scaling: Automatically predicts future workloads and adjusts ECS instances accordingly.

Elastic Self-Diagnostic is not a feature supported by Alibaba Cloud Auto Scaling.It is a fictitious term that does not exist in the Alibaba Cloud documentation or course materials.Reference:1: Auto Scaling: Automatically Adjusts Computing Resources - Alibaba Cloud2: Auto Scaling:What is Auto Scaling? - Alibaba Cloud

Answer : A

ECS can be used along with OSS to store static images, videos, and reducing storage fees. OSS is a fully managed object storage service that provides industry-leading scalability, durability, and performance. OSS can store any amount of data from anywhere, such as static images, videos, backup files, and so on. ECS is a cloud computing service that provides elastic and secure virtual cloud servers. ECS can access OSS resources by using an internal endpoint of OSS, which reduces the network latency and the traffic costs.By using ECS and OSS together, you can benefit from the following advantages1:

Improved user experience: You can use OSS to store and deliver static content, such as images and videos, to your users. OSS integrates with CDN products to provide reliable, scalable, flexible, and cost-effective content distribution solutions. You can use ECS to run dynamic applications, such as web servers and databases, that require high performance and availability. ECS provides fast memory and the latest CPUs to help you power your cloud applications and achieve faster results with low latency.

Reduced storage fees: You can use OSS to store large amounts of data at a low cost. OSS offers four tiers of storage: Standard, Infrequent Access, Archive, and Cold Archive. Each tier is cost-optimized for specific storage patterns. You can use lifecycle policies to automatically transition your data to the appropriate storage tier based on your business needs. You can also use Storage Capacity Unit to plan your storage budget and usage in one place. You can use ECS to scale your computing resources up or down based on real-time demands. ECS supports pay-as-you-go and different capacity reservation plans. You can also use spot instances to reduce your computing costs by up to 90%.

Enhanced security: You can use OSS to protect your data from unauthorized access, deletion, or modification. OSS supports encryption at rest and in transit, anti-leech protection, bucket policies, RAM roles, and more. You can also use your own key (BYOK) encryption to ensure your data is encrypted when it is stored in the cloud platform. You can use ECS to secure your cloud servers from network attacks, such as DDoS and brute force attacks. ECS supports security groups, firewalls, VPCs, SSL certificates, and more. You can also use Resource Access Management (RAM) to control the access permissions of your ECS instances and OSS buckets.Reference:Use Alibaba Cloud CDN to accelerate access to OSS

Answer : B

A snapshot is a copy of data on a disk at a certain point in time. It is used to back up and restore data, or create custom images.Snapshots can capture the data of system disks, data disks, and shared block storage devices1.