ACP-Cloud1 Exam Dumps - Alibaba Cloud Computing Questions and Answers

Enabling SELinux on an ECS instance does not interfere with Alibaba Cloud’s ECS monitoring features. SELinux is a security module that enforces mandatory access controls on Linux systems. It operates independently from the monitoring capabilities provided by the ECS console, so ECS metrics and monitoring functions remain unaffected when SELinux is enabled.

 You can change the private IP address of an ECS instance after it is created, but you need to stop the instance first. The private IP address must be within the CIDR block of the VPC and the VSwitch that the instance belongs to. You can modify the private IP address of an instance by using the console or the API. References: 3, ACP Cloud Computing Certification - Alibaba Cloud Academy

After stopping an Alibaba Cloud Elastic Compute Service (ECS) instance, you will still be charged for some resources related to that ECS instance, such as disks, snapshots, and public IP addresses, until you release them. The charging policy depends on the billing method and network type of the ECS instance. For pay-as-you-go instances, you can choose whether to enable the No fees for stopped instances feature, which allows you to stop paying for vCPUs and memory when the instance is stopped. However, this feature is only available for VPC-connected instances in some regions1. For subscription instances, you will be charged for the entire subscription period regardless of whether the instance is running or stopped2. References:

1: Billing FAQ - Elastic Compute Service - Alibaba Cloud Documentation Center1

2: Billing overview - Elastic Compute Service - Alibaba Cloud Documentation Center2

OSS does not use a hierarchical structure for objects, but instead uses a flat structure. All elements are stored as objects in buckets. To use OSS in the same manner in which local file systems are used, you can configure Cloud Storage Gateway (CSG).

https://www.alibabacloud.c om/help/doc-detail/31817.htm

 The statement C is correct, because in an OSS bucket, all elements are stored as objects. An object is the basic unit of OSS storage. Each object consists of a unique key, data, and metadata. The key is the name of the object, which is used to identify the object in a bucket. The data is the content of the object, which can be any type of file, such as text, image, video, or audio. The metadata is the information about the object, such as its size, type, creation time, and custom attributes. References: = Object Storage Service:Overview - Alibaba Cloud

Alibaba Cloud OSS provides three primary access permissions for buckets: Private, Public-read, and Public-read-write.

Private: Only the owner has access to read or write data.

Public-read: The owner can read and write, but others can only read.

Public-read-write: The bucket is fully open for reading and writing by all users.There is no Private-read permission in OSS access control options, so option A is incorrect.

In Alibaba Cloud RDS, both the master and read-only instances must reside within the same region. Cross-region replication for RDS read-only instances is not supported, as RDS read replicas are designed for high availability and load balancing within a single region.

Alibaba Cloud OSS offers Server Side Encryption to protect data at rest, enhancing security. It also supports multi-region replication with Primary/Secondary region configurations for additional data reliability and disaster recovery. Anti-DDoS is not an inherent feature of OSS, and multi-user isolation is achieved via Alibaba Cloud’s Resource Access Management (RAM).

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Different Alibaba Cloud VPCs are completely isolated from each other by default, but they can communicate with each other over the intranet by using different methods, such as Cloud Enterprise Network (CEN), VPN gateways, VPC peering connections, and PrivateLink. These methods allow you to establish secure and reliable connections between VPCs without exposing your network traffic to the internet. References:

Overview of VPC connections - Alibaba Cloud

Cross-VPC peering - Alibaba Cloud

ALIYUN::VPC::VpcPeerConnection - Alibaba Cloud

Alibaba Cloud ECS Open API supports both HTTP GET and POST requests. While GET requests are common, POST requests are often used for secure data transfer and handling complex request parameters. Therefore, you are not limited to using only GET requests when interacting with the ECS API.

Auto Scaling in Alibaba Cloud is designed to automatically adjust resources, such as ECS instances, based on the demand and scaling policies. This works best with applications that are stateless and horizontally scalable, as these applications do not rely on data stored locally on an instance, allowing them to scale in and out without affecting performance or user experience. Statelessness and horizontal scalability allow Auto Scaling to manage ECS instances efficiently without manual intervention.

Alibaba Cloud SLB can distribute user requests to backend ECS instances, but these ECS instances do not have to have the same specification (CPU, Memory). SLB virtualizes the added group of ECS instances in the same region into an application pool, and you can manage backend servers through either the default server group, a primary server group, or VServer groups. You can add ECS instances of different specifications to the same server group or VServer group according to your needs. SLB supports weighted round-robin (WRR) and weighted least connections (WLC) algorithms to balance the load among backend servers with different weights. References:

SLB overview - Alibaba Cloud

Backend server overview - Alibaba Cloud

What is Server Load Balancer and How It Works - Alibaba Cloud

Server Load Balancer - Alibaba Cloud

Alibaba Server Load Balancer (SLB) Course - Cloud Academy