Alibaba aca-operator practice test

ACA System Operator Certification Exam

Question 1

Which of the following features are unique to Alibaba Cloud Container Registry, as compared with
Docker Hub? (Number of correct answers: 2)

  • A. Container Registry can automatically build new Docker images when source code changes.
  • B. For source code hosted on websites outside China, Container Registry can use servers outside China to build Docker images, even when you are using a Container Registry instance in Mainland China.
  • C. You can create and delete image repositories in different regions based on your needs.
  • D. You can set your image repository access to public or private.

B, C


Question 2

When you use SQL statements to access tables in a database without an index configured, a full table
scan will be performed. If a table contains a large amount of data, this kind of scan will access a large
amount of data and consume a lot of the database's resources. Which of the following options are
best practices when creating database indexes? (Number of correct answers: 3)

  • A. Add an index to a field that is frequently queried but does not frequently perform add, delete, or modify operations.
  • B. Applies indices to fields to contain many records.
  • C. A table should not contaiiAiore than 6 indexed fields.
  • D. Apply indexing to fields of fixed length (preferably not long fields).
  • E. Adhere to the rightmost prefix principle when using composite indexes

A, C, D


Question 3

A Developer is creating a Function Compute function. This function requires around 1 GB of
temporary storage for files while executing. These files will not be needed after the function is
completed for a fixed period. How can this developer MOST efficiently handle the temporary files?

  • A. Store the files in Cloud Disk and delete the files when Function Compute function call completes.
  • B. Copy the files to NFS and delete the files when the Function Compute function call completes.
  • C. Store the files in the /tmp directory on a temporary ECS instance, and delete the files at when the Function Compute function call completes.
  • D. Copy the files to an OSS bucket with a lifecycle policy configured to delete the files automatically.



Question 4

Alibaba Cloud RocketMQ is typically used in scenarios where message publishing and consumption
performance requirements are high. Which of the following are supported message types in Alibaba
Cloud RocketMQ? (Number of correct answers: 3)

  • A. Scheduled message
  • B. Ordered message
  • C. Batched message
  • D. Transactional message
  • E. Retried message

A, B, D


Question 5

You can create an event notification rule in Message Service and push notifications to the specified
consumer in the form of messages, to receive events from specified Alibaba Cloud resources. Which
of the following options are correct statements about the Message Service (MS) service? (Number of
correct answers: 2)

  • A. Event Notifications can cross regions.
  • B. Message Service provides synchronous notification to ensure the consistency between the message acknowledgment and event processing.
  • C. The event notification message is retained within the valid time. When you fail to receive an event message, the event notification message is retained based on the specified retry policy.
  • D. The consumer type of the event notification message can be HTTP Server, Queue, or Topic.

C, D


Question 6

When using Alibaba Cloud CDN, a visitor's request will first be routed to a CDN edge node, and in the
event of a cache miss at this edge node, the node will fetch data from the origin site (back-to-source
request). Even with this redirection, it is possible for the origin site to see the visitor's real IP address.
Which of the following statements about obtaining the visitor's real IP address are correct? (Number
of correct answers: 2)
A visitor's real IP address can only be obtained by modifying the site or web application.
B. visitor's real IP address is stored in the "X-Forwarded-For" HTTP header. It can be directly obtained
via Apache or NGINX logs.
C. In Windows, if IIS is used, after installing the "F5XForwardedFor" extension module, the visitor's
real IP address can be seen via IIS logs.
D. You can activate the "record visitor's real IP" function in the Alibaba Cloud CDN console, then you
can directly view visitor's IP addresses from the Alibaba Cloud CDN access logs.


B, C


Question 7

Which of the following database connection methods does ApsaraDB for Redis support? (Number of
correct answers: 2)

  • A. DMS (Data Management Service)
  • B. Aliyun-cli
  • C. Redis-cli
  • D. Sentinel

A, C


Question 8

A developer is making the ModifyDBInstanceSpec API call to change the specifications of an RDS
instance, but the operation fails. Why could this be? (Number of correct answers: 3)

  • A. The instance is in the "running" state
  • B. No instance type (specification) was included in the request parameters
  • C. The instance has a backup task being executed
  • D. The targeted RDS instance is a disaster recovery instance

B, C, D


Question 9

Which of the following options are correct for Multipart Upload and Resumable Upload in Object
Storage Service (OSS)? (Number of correct answers: 3)

  • A. Use Multipart Upload to upload multiple parts of a file in parallel to speed up the upload process
  • B. Multipart Upload is usually used when the size of the file to be uploaded is large
  • C. If the upload fails due to an accident during the uploading of fragments, you need to upload all the fragments again
  • D. After an upload is interrupted, the portions of the file which have successfully uploaded prior to the interruption will be saved in the OSS bucket

A, B, D


Question 10

Which of the following descriptions of the principles of Alibaba Cloud SSL certificate private key
protection is correct?

  • A. Alibaba Cloud uses the built-in functionality of the SSL certificate service to encrypt and store the private key to ensure the security of your certificate's private key
  • B. The plaintext of Alibaba Cloud's private key is usually stored on disk and backed up regularly
  • C. Alibaba Cloud Certificate Service uses symmetric encryption to save the certificate private key.
  • D. Alibaba Cloud Certificate Service keys are loaded into memory in plaintext format ONLY when needed.


To page 2