Alibaba ACP-Cloud1 Exam Practice Test Instant Access

Question 1

Which of the following database engines are compatible with RDS? (Choose three.)

AMySQL

BPostgreSQL

CSQL Server

DPPAS

ESybase

Answer : A, B, C

Alibaba Cloud RDS supports several popular database engines, including MySQL, PostgreSQL, and SQL Server. PPAS (PostgreSQL Plus Advanced Server) is also supported but not Sybase, which is not available as an RDS option on Alibaba Cloud.

Question 2

A user builds an ECS + SLB + RDS architecture on Alibaba Cloud, with Auto Scaling to dynamically manage ECS instances. For business needs, they use ApsaraDB for Redis as a cache for hot data, requiring ECS instances to be added or removed from the Redis whitelist as they scale. As an Alibaba Cloud architect, which three Auto Scaling and OOS features would you recommend to automate adding and removing instances from the Redis whitelist? (Choose three.)

AAuto-Scaling lifecycle hooks

BOOS Template

CMNS

DInstance launch template

Answer : A, B, C

Using lifecycle hooks in Auto Scaling allows for custom operations, such as updating the Redis whitelist when instances are added or removed. An OOS (Operation Orchestration Service) template can automate this process, and MNS (Message Notification Service) can trigger events to inform Redis when changes occur.

Question 3

In Auto Scaling, the cool-down time of a scaling group refers to the lockout period after a scaling activity has been executed successfully. Which of the following statements about cool-down time are true? (Choose two.)

ADuring the cool-down time, only the scaling activities in the same scaling group are locked.

BYou can't skip a scaling group's cool-down time period right after a scaling activity is just finished.

CWhen multiple ECS instances are added or removed from a scaling group, the cool-down time begins only when the last instance has been added or removed from the scaling group.

DDuring the cool-down time of a scaling group, only the alarms from CloudMonitor can bypass the cool-down time and trigger scaling activities, whereas other scaling activities, such as manually triggered ones, will still be subject to the cool-down time.

Answer : A, C

During cool-down time, scaling activities in the same scaling group are temporarily locked to avoid unnecessary scaling activities. The cool-down time begins once all ECS instances in a multi-instance scaling action are added or removed.

Question 4

Alibaba Cloud Content Delivery Network (CDN) is a distributed network built on top of a base network with edge node server clusters distributed across various regions. If a user finds that the CDN cache hit rate is low, the possible reasons are ____________. (Choose three.)

AWhen websites have low access traffic and the files are not popular enough, the CDN will receive fewer requests and result in a lower cache hit rate.

BIf the cache configuration is inappropriate (e.g., overly short Cache Expiry Time for popular files), this may result in frequent back-to-source operations.

CInsufficient bandwidth was selected when enabling the CDN service, making the service capacity reach its limit.

DIf the origin site has a large number of dynamic resources or mostly non-cacheable content, this can also lead to frequent back-to-source operations.

EThe HTTP Header setting may cause the cache to fail. In this case, users must check the origin site's ''Cache-Control'' and ''Expires'' settings.

Answer : A, B, D

A low CDN cache hit rate can be due to low website traffic, poor cache configurations (such as a short Cache Expiry Time), or the presence of dynamic resources that require frequent retrieval from the origin. Proper configuration of 'Cache-Control' and 'Expires' headers is necessary to ensure caching.

Question 5

Availability Zones refer to data centers in the same region with independent power grids and networks. Which of the following statements are true for Zones? (Choose three.)

AIf the disaster recovery requirements of your applications are demanding, it is recommended that you deploy ECS instances in the same Region and Zone.

BThe network latency between inter-Zone ECS instances is lower.

CIntranet communication is available between different Zones in the same region, and data center-level fault isolation can be achieved between Zones.

DWhether you place ECS instances in the same Zone depends on the requirements for disaster recovery and network latency.

EIf your applications require low network latency between ECS instances, it is recommended that you create ECS instances in different Zones.

Answer : B, C, D

Zones in the same region support low-latency intranet communication, ideal for high-availability deployments with inter-Zone fault isolation. Placement of ECS instances in the same or different Zones depends on the disaster recovery and latency needs of the application.

Question 6

When using Alibaba Cloud SLB, users can enable the Health Check function. Layer-4 SLBs (TCP protocol) determine the availability of ECS instances through _________________.

AWhether the 3-way handshake can be established between the backend ECS instance and the SLB.

BSpecial characters contained in the message returned from backend ECS instances.

CStatus codes returned from backend ECS instances.

DLength of the message returned from backend ECS instances.

Answer : A

For Layer-4 SLB using TCP, the health check determines ECS instance availability based on the successful completion of a TCP 3-way handshake. This ensures that the backend server is reachable and can accept connections, which is critical for reliable TCP-based load balancing.

Question 7

A company uses Alibaba Cloud SLB with a Layer-7 Listener and Auto Scaling to reduce O&M costs and maintain a stable, reliable system. However, lacking experience with Alibaba Cloud, the company's engineers have outlined precautions they think are necessary. As an Alibaba Cloud expert, you tell them that only ____________ is a valid concern.

ASLB instances must have Health Check enabled, or they cannot be used together with Auto Scaling.

BAll ECS instances under the same SLB instance must be running the same operating system.

CAll backend servers under the same SLB instance must be in the same Scaling Group.

DAll backend servers under the same SLB instance must have the same configuration.

Answer : A

For optimal use of SLB with Auto Scaling, enabling Health Check is essential to determine which instances are healthy and ready to handle traffic. SLB doesn't require all backend servers to have the same OS, be in the same scaling group, or have identical configurations, as it can manage heterogeneous server setups within the same load-balancing group.

Alibaba ACP-Cloud1 ACP Cloud Computing Certification Exam Practice Test