ACP-Cloud1 Exam Dumps : ACP Cloud Computing Certification

According to the Alibaba Cloud ECS documentation1, the recommended instance type for Tomcat is ecs.c5.xlarge, which has 4 vCPUs and 4 GiB of memory. This instance type is suitable for web applications that require high performance and low latency. The recommended instance type for Memcache is ecs.r5.large, which has 2 vCPUs and 16 GiB of memory. This instance type is optimized for memory-intensive applications that require high memory bandwidth and low latency. Therefore, option D is the most recommended configuration for deploying Tomcat and Memcache on two ECS instances. References: Instance type families and Alibaba Cloud Elastic Compute Service Product Introduction

ApsaraDB for RDS is a stable and reliable online database service that supports MySQL, SQL Server, PostgreSQL, MariaDB, and PPAS. ApsaraDB for RDS provides a read/write splitting feature that allows you to create read-only RDS instances, which can offload read requests from the primary RDS instance of your database system1. Read/write splitting is implemented by using a dedicated proxy endpoint, which routes read and write requests to different RDS instances based on the SQL statements and the read weights of the read-only instances2. By using ApsaraDB for RDS to implement read/write splitting, you can achieve the following benefits21:

Read requests are distributed to multiple instances. This can improve the read performance and availability of your database system, as well as balance the load among the read-only instances. You can specify the read weights of the read-only instances to control the distribution of read requests.

Read/write requests to the database are separated. This can reduce the pressure on the primary RDS instance and ensure the stability and security of the write operations. You only need to connect to the proxy endpoint, and the proxy will automatically route the read and write requests to the appropriate RDS instances.

The other statements are not correct, as write requests are not distributed to multiple instances, but only sent to the primary RDS instance2; and both read and write requests are not distributed to multiple instances, but separated by the proxy endpoint2. References: [ApsaraDB for RDS - Alibaba Cloud], Read/write splitting - - Alibaba Cloud Documentation Center, Use the read/write splitting feature to increase the processing capability of an ApsaraDB RDS instance

A route table is a set of rules that determine how network traffic is routed within a VPC or between different network instances1. A VRouter is a hub that connects all VSwitches in the same VPC and enables communication between them2. When you create a VPC, a VRouter and a default route table are automatically created for the VPC1. The default route table contains system routes that are automatically generated by the system based on the network topology1. The system routes cannot be modified or deleted1.

However, you can also create custom route tables for your VPC and add custom routes to them1. Custom routes are manually configured by users to route traffic to specific destinations, such as other VPCs, VBRs, VPN Gateways, or NAT Gateways1. Custom routes can be modified or deleted as needed1. You can also associate VSwitches with different route tables to implement fine-grained routing control1.

Therefore, the statement that the routing entries of the route table can not be modified manually is not correct, as it only applies to system routes, not custom routes. The other statements are correct, as each VRouter may have multiple route tables, one default and several custom1; when a VPC is deleted, the corresponding route table is also deleted3; and the default route table cannot be deleted1. References: Route table overview - Virtual Private Cloud - Alibaba Cloud Documentation Center, VRouter overview - Virtual Private Cloud - Alibaba Cloud Documentation Center, Delete a VPC - Virtual Private Cloud - Alibaba Cloud Documentation Center