Free Alibaba ACP Cloud Computing Certification Exam ACP-Cloud1 Exam Questions

Latency on an RDS read-only instance can be caused by high loads on the instance itself, inadequate instance specifications, or excessive write operations on the master instance, as these factors directly impact replication delay and resource contention. However, a high load on the ECS instance connected to the RDS read-only instance would not inherently cause latency on the RDS instance, as the ECS and RDS operate independently in terms of processing.

RDS for MySQL supports connections through tools that are compatible with MySQL, such as MySQL-Front, Navicat MySQL, and command-line MySQL commands. SQL Server Management Studio (SSMS) is designed for Microsoft SQL Server and is not compatible with MySQL, so option D is incorrect.

In Alibaba Cloud, resizing the system disk of an ECS instance requires stopping the instance temporarily. This ensures data integrity and successful resizing. Once the system disk is resized, the instance can be restarted to reflect the new disk size.

Alibaba Cloud VPC uses tunneling technology with unique tunnel IDs to create isolated virtual networks that offer similar isolation capabilities as VLANs in traditional networks. This allows each VPC to function as an independent, secure network environment within the cloud, ensuring traffic separation and resource isolation.

By default, ECS instances in different zones within the same region are not interconnected via the Intranet. To enable communication between instances across zones, you would need to configure a VPC or use other network configurations. This setup provides isolation and flexibility in managing network traffic within different zones.

Before data communication is set up, the security groups match the security group rules one by one to query whether to allow access requests. If the protocol type, port range, authorization type, and authorization object of two security group rules are the same, the following rules apply:

If the two rules have the same priority, the rule of the denial policy takes effect first, and the rule of the allowed policy does not take effect. This is because the security group rules follow the principle of minimum permission, which means that the most restrictive rule is applied when there is a conflict.

If the two rules have different priorities, the rule with a smaller priority number takes effect. This is because the security group rules follow the principle of priority, which means that the rule with a higher priority (lower number) is applied when there is a conflict. Reference: ECS Security Groups - Alibaba Fundamentals - Cloud Academy, Security group rules - Elastic Compute Service - Alibaba Cloud Documentation Center

Object Storage Service (OSS) supports sub accounts, which are the accounts that belong to a parent account and share the resources of the parent account. You can allocate access permissions to different buckets for each sub account by using bucket policies or RAM policies. Bucket policies are the access control policies that are attached to buckets and specify the permissions that other users have on the resources in the buckets. RAM policies are the access control policies that are attached to RAM users or RAM user groups and specify the permissions that the RAM users or RAM user groups have on the OSS resources. Reference:

Object Storage Service:Overview - Alibaba Cloud

Object Storage Service:FAQ - Alibaba Cloud

Authentication - Object Storage Service - Alibaba Cloud

The safest response to a seldom-used IP alert connecting to ApsaraDB for RDS is to adjust the IP whitelist to allow only trusted IP addresses. By limiting the IP addresses in the whitelist, unauthorized or unfamiliar IP addresses cannot access the database. This approach provides direct control over access to RDS and minimizes potential security risks. Checking SQL audit logs (as suggested in option D) is useful but not sufficient on its own for a comprehensive security response.

To prevent frequent alerts when User A logs in from Shanghai, the best solution is to configure the Security Center to recognize Shanghai as a frequent login location. This will prevent unnecessary security alerts each time User A accesses the server from this location.

The X-Forwarded-For field in HTTP header is used to identify the originating IP address of a client connecting to a web server through an HTTP proxy or a load balancer. When the ''Obtain the Visitor's Real IP Address'' function is enabled in Alibaba Cloud SLB, the SLB instance adds the X-Forwarded-For field to the HTTP header of each request and forwards the request to the backend server. The backend server can then obtain the real IP address of the visitor from the X-Forwarded-For field1. The format of the X-Forwarded-For field is as follows:

X-Forwarded-For: client, proxy1, proxy2

where the value is a comma+space separated list of IP addresses, the left-most being the original client, and each successive proxy that passed the request adding the IP address where it received the request from. In this example, the request passed through proxy1, proxy2, and then the SLB instance (proxy3).2

Data Transmission Service (DTS) is a real-time data streaming service that supports data transmission between data sources such as relational databases, NoSQL, and Big Data (OLAP). DTS supports data migration, data synchronization, and change data subscription scenarios. DTS can migrate your data to and from most of the widely used commercial and open source databases. It supports homogeneous migrations such as MySQL to MySQL, as well as heterogeneous migrations between different database platforms, such as Oracle to MySQL. Migrations can be from on-premises databases to RDS or ECS, databases running on ECS to RDS, or vice versa, as well as from one RDS database to another RDS database. DTS also supports migrating data between RDS instances of different Alibaba Cloud accounts, as long as they are in the same region1. Therefore, the statement B. The data cannot be migrated is NOT correct for migrating self-built MySQL databases (running on ECS) to RDS. The other statements are correct, as the data can be imported via the Intranet, the public network, or by running mysqldump234. Reference:

1: Migrate Self-built Database to RDS - Alibaba Cloud

2: Migrating a Self-built MySQL Database to Alibaba Cloud RDS for MySQL with Minimal Downtime - Alibaba Cloud Community

3: Migrating Data from a Self-Managed SQL Server Database on an ECS to an ApsaraDB RDS for SQL Server Database

4: Migrate data between RDS instances of different Alibaba Cloud accounts,Data Transmission Service

Not all upload methods in Alibaba Cloud OSS support resuming from a breakpoint. Only specific methods, such as multipart upload, support this feature. Small files can be uploaded using a single PUT request, while APPEND is useful for continuously updated log files. For large files, multipart uploading is recommended to handle potential interruptions.

Weighted Round Robin (WRR) is a load balancing mode that assigns requests to backend ECS instances based on their weights. The higher the weight of the backend ECS instance, the higher the chance that the instance will receive requests. This mode can exploit the different service capacities of backend ECS instances by setting higher weights to ECS instances with higher capacities. For example, if there are two ECS instances in the backend server pool, one with a weight of 10 and the other with a weight of 20, the ECS instance with a weight of 20 will receive twice as many requests as the ECS instance with a weight of 10.

1: SLB overview - Server Load Balancer - Alibaba Cloud Documentation Center

4: Server Load Balancer - Alibaba Cloud

5: Alibaba Server Load Balancer (SLB) Course - Cloud Academy

CloudMonitor allows users to create custom monitoring metrics and report data, which can then be analyzed and used for alerts. Customized monitoring is flexible, with no set limits on the number of metrics, and users can report data from Alibaba Cloud servers or other devices.

Default and non-default VSwitches do not have the same constraints and operations. Default VSwitches have specific configurations and limitations set by Alibaba Cloud, designed to simplify initial setups. In contrast, non-default VSwitches, created by users, allow for more customized configurations and are typically used in more complex or specialized networking environments. Thus, option C is incorrect as the constraints and operations differ between default and non-default VSwitches.