Alibaba Cloud ACP-Cloud1 - ACP Cloud Computing Certification

In Alibaba Cloud VPCs, only custom route tables can be created and deleted by users. The default route table associated with each VPC cannot be deleted, although custom routing entries within it can be modified. This limitation ensures the integrity of essential VPC networking components.

=================

 According to the Alibaba Cloud SLB documentation1, SLB provides a health check feature that monitors the availability and performance of the backend servers. If a backend server fails the health check, SLB stops routing requests to it and redirects the traffic to other healthy servers. This way, SLB can improve the system’s availability by eliminating single points of failure (SPOFs). Therefore, option A is a correct statement about SLB.

According to the same documentation1, SLB instances are assigned with public IP addresses or private IP addresses based on the network type. If you delete an SLB instance and create a new one, a new IP address will be allocated to the new instance. You cannot specify or reserve an IP address for an SLB instance. Therefore, option B is also a correct statement about SLB.

Option C is incorrect, because SLB does not require you to install or configure any SLB agent on the backend servers. You only need to add the backend servers to the SLB instance and configure the listener and the server group. SLB will automatically distribute the traffic to the backend servers based on the load balancing algorithm and the health check status2.

Option D is also incorrect, because SLB does not provide a function to automatically synchronize data among backend servers. SLB only handles the network traffic distribution and does not interfere with the data on the backend servers. You need to use other methods or tools to synchronize data among backend servers, such as rsync, lsyncd, or Alibaba Cloud Data Transmission Service (DTS)3.

References: Server Load Balancer:SLB overview, Add backend servers, and Data Transmission Service.

In this scenario, a combination of Server Load Balancer (SLB), ECS, ApsaraDB for RDS, and Auto Scaling is ideal. SLB distributes incoming traffic across multiple ECS instances, ensuring high availability and reliability. Auto Scaling automatically adjusts the number of ECS instances based on demand, managing costs efficiently by scaling out during peak times and scaling in when demand decreases. ApsaraDB for RDS provides a managed database service that handles increasing database demands without requiring complex manual scaling. This portfolio is optimal for fluctuating gaming traffic as it ensures load balancing, scalability, and cost control.

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

When using Auto Scaling with Server Load Balancer (SLB), both the scaling group and the SLB instance must reside in the same region. This is because region-specific configurations enable low-latency connections and proper integration between the resources, ensuring the scaling group can register with the SLB instance effectively.

Certificates are mandatory when using the HTTPS protocol with Alibaba Cloud SLB to secure data transmission between clients and the SLB instance. HTTPS (HTTP Secure) requires an SSL/TLS certificate to encrypt the data, ensuring secure communication over the network. For protocols like HTTP or TCP, a certificate is not required, as they do not natively support encryption.

There is no limit on the number of objects that can be stored in a single OSS bucket in Alibaba Cloud. OSS is designed to support massive data storage, allowing users to store an unlimited number of files within a bucket. The only limitations are the bucket storage capacity and account-level quotas.

=================

When creating an ECS instance in your Alibaba Cloud VPC, you must specify a VSwitch for that instance at the same time. Otherwise, you will not be able to create this ECS instance. This is true according to the Alibaba Cloud documentation on ECS1. A VSwitch is a basic network device of a VPC and is used to connect different cloud product instances deployed in a VPC2. A VSwitch defines a network segment within a VPC and allows you to specify the IP address range, network mask, and gateway for the network segment2. When you create an ECS instance, you must select a VSwitch that belongs to the same zone as the ECS instance3. If you do not specify a VSwitch, the ECS instance will not be able to communicate with other cloud product instances in the VPC or access the Internet. References: 1: Create an instance by using the provided wizard - Elastic Compute Service - Alibaba Cloud Documentation Center 2: What is a VSwitch? - Virtual Private Cloud - Alibaba Cloud Documentation Center 3: Create an instance by using the advanced wizard - Elastic Compute Service - Alibaba Cloud Documentation Center : [VPC FAQ - Virtual Private Cloud - Alibaba Cloud Documentation Center]

Alibaba Cloud CDN (Content Delivery Network) can be used with OSS to accelerate the delivery of static content by caching data at edge nodes closer to end-users. This combination is ideal for static websites, as CDN reduces latency and enhances the loading speed of web pages hosted on OSS. By serving content from multiple distributed nodes, CDN provides users with faster, more efficient access to static resources.

According to the Alibaba Cloud Auto Scaling documentation1, the Lifecycle Hook feature allows you to perform custom operations on instances that are added to or removed from a scaling group. You can define a lifecycle hook to specify a timeout period and a web hook URL. When an instance is about to be removed, Auto Scaling sends a notification to the web hook URL and waits for a response. During the timeout period, you can perform the necessary operations on the instance, such as gracefully shutting down the service, backing up the data, or sending a custom notification. After the operations are completed, you can send a response to the web hook URL to confirm the removal of the instance. This way, you can ensure that the instance is removed without affecting the user experience or causing data loss. Therefore, option D is the best solution to eliminate the customer’s concern. References: Lifecycle hooks and Alibaba Cloud Auto Scaling.