SAP-C02 第 8 题
题目
A company has a multi-tier web application that runs on a fleet of Amazon EC2 instances behind an Application Load Balancer (ALB). The instances are in an Auto Scaling group. The ALB and the Auto Scaling group are replicated in a backup AWS Region. The minimum value and the maximum value for the Auto Scaling group are set to zero. An Amazon RDS Multi-AZ DB instance stores the application’s data. The DB instance has a read replica in the backup Region. The application presents an endpoint to end users by using an Amazon Route 53 record. The company needs to reduce its RTO to less than 15 minutes by giving the application the ability to automatically fail over to the backup Region. The company does not have a large enough budget for an active-active strategy. What should a solutions architect recommend to meet these requirements?
中文翻译：
一家公司有一个多层 Web 应用程序，该应用程序在应用程序负载均衡器 (ALB) 后面的一组 Amazon EC2 实例上运行。这些实例位于 Auto Scaling 组中。 ALB 和 Auto Scaling 组将复制到备份 AWS 区域中。 Auto Scaling 组的最小值和最大值设置为零。 Amazon RDS 多可用区数据库实例存储应用程序的数据。数据库实例在备份区域中有一个只读副本。该应用程序使用 Amazon Route 53 记录向最终用户提供终端节点。该公司需要通过赋予应用程序自动故障转移到备份区域的能力，将 RTO 减少到 15 分钟以下。该公司没有足够大的预算来实施主动-主动策略。解决方案架构师应该建议什么来满足这些要求？
选项
A. Reconfigure the application’s Route 53 record with a latency-based routing policy that load balances traffic between the two ALBs. Create an AWS Lambda function in the backup Region to promote the read replica and modify the Auto Scaling group values. Create an Amazon CloudWatch alarm that is based on the HTTPCode_Target_5XX_Count metric for the ALB in the primary Region. Configure the CloudWatch alarm to invoke the Lambda function.
中文翻译：
使用基于延迟的路由策略重新配置应用程序的 Route 53 记录，以平衡两个 ALB 之间的流量负载。在备份区域中创建 AWS Lambda 函数以提升只读副本并修改 Auto Scaling 组值。创建基于主要区域中 ALB 的 HTTPCode_Target_5XX_Count 指标的 Amazon CloudWatch 警报。配置 CloudWatch 警报以调用 Lambda 函数。
B. Create an AWS Lambda function in the backup Region to promote the read replica and modify the Auto Scaling group values. Configure Route 53 with a health check that monitors the web application and sends an Amazon Simple Notification Service (Amazon SNS) notification to the Lambda function when the health check status is unhealthy. Update the application’s Route 53 record with a failover policy that routes traffic to the ALB in the backup Region when a health check failure occurs.
中文翻译：
在备份区域中创建 AWS Lambda 函数以提升只读副本并修改 Auto Scaling 组值。使用运行状况检查配置 Route 53，该运行状况检查可监控 Web 应用程序，并在运行状况检查状态不正常时向 Lambda 函数发送 Amazon Simple Notification Service (Amazon SNS) 通知。使用故障转移策略更新应用程序的 Route 53 记录，该策略在发生运行状况检查失败时将流量路由到备份区域中的 ALB。
C. Configure the Auto Scaling group in the backup Region to have the same values as the Auto Scaling group in the primary Region. Reconfigure the application’s Route 53 record with a latency-based routing policy that load balances traffic between the two ALBs. Remove the read replica. Replace the read replica with a standalone RDS DB instance. Configure Cross-Region Replication between the RDS DB instances by using snapshots and Amazon S3.
中文翻译：
将备份区域中的 Auto Scaling 组配置为与主区域中的 Auto Scaling 组具有相同的值。使用基于延迟的路由策略重新配置应用程序的 Route 53 记录，以平衡两个 ALB 之间的流量负载。删除只读副本。将只读副本替换为独立的 RDS 数据库实例。使用快照和 Amazon S3 在 RDS 数据库实例之间配置跨区域复制。
D. Configure an endpoint in AWS Global Accelerator with the two ALBs as equal weighted targets. Create an AWS Lambda function in the backup Region to promote the read replica and modify the Auto Scaling group values. Create an Amazon CloudWatch alarm that is based on the HTTPCode_Target_5XX_Count metric for the ALB in the primary Region. Configure the CloudWatch alarm to invoke the Lambda function.
中文翻译：
在 AWS Global Accelerator 中配置终端节点，将两个 ALB 作为相等权重目标。在备份区域中创建 AWS Lambda 函数以提升只读副本并修改 Auto Scaling 组值。创建基于主要区域中 ALB 的 HTTPCode_Target_5XX_Count 指标的 Amazon CloudWatch 警报。配置 CloudWatch 警报以调用 Lambda 函数。
答案
B
解析
正确答案：B 解析： 本题应选择 B。 正确选项： B. 在备份区域中创建 AWS Lambda 函数以提升只读副本并修改 Auto Scaling 组值。使用运行状况检查配置 Route 53，该运行状况检查可监控 Web 应用程序，并在运行状况检查状态不正常时向 Lambda 函数发送 Amazon Simple Notification Service (Amazon SNS) 通知。使用故障转移策略更新应用程序的 Route 5...