Amazon Web Services Updated CLF-C02 Exam Questions and Answers by yasin

The company should use AWS WAF to safeguard the website from SQL injection or cross-site scripting. AWS WAF is a web application firewall that helps protect web applications from common web exploits that could affect availability, compromise security, or consume excessive resources. The company can use AWS WAF to create custom rules that block malicious requests that match certain patterns, such as SQL injection or cross-site scripting. AWS WAF can be applied to web applications that are behind an Application Load Balancer, Amazon CloudFront, or Amazon API Gateway. Amazon GuardDuty, AWS Trusted Advisor, and Amazon Inspector are not the best services to use for this purpose. Amazon GuardDuty is a threat detection service that monitors for malicious activity and unauthorized behavior across the AWS accounts and resources. AWS Trusted Advisor is a service that provides best practice recommendations for cost optimization, performance, security, and fault tolerance. Amazon Inspector is a service that assesses the security and compliance of applications running on Amazon EC2 instances12

 Using EC2 instances across multiple Availability Zones in the same AWS Region is a solution that meets the requirements of sharing the same geographic area but using redundant underlying power sources. Availability Zones are isolated locations within an AWS Region that have independent power, cooling, and physical security. They are connected through low-latency, high-throughput, and highly redundant networking. By launching EC2 instances in different Availability Zones, users can increase the fault tolerance and availability of their applications. Amazon CloudFront is a content delivery network (CDN) service that speeds up the delivery of web content and media to end users by caching it at the edge locations closer to them. It is not a database service and cannot be used to store operational data for EC2 instances. Edge locations are sites that are part of the Amazon CloudFront network and are located in many cities around the world. They are not the same as Availability Zones and do not provide redundancy for EC2 instances. AWS OpsWorks is a configuration management service that allows users to automate the deployment and management of applications using Chef or Puppet. It can be used to create stacks that span multiple AWS Regions, but this would not meet the requirement of sharing the same geographic area.

The solution that meets the requirement of the company that runs a database on Amazon Aurora in the us-east-1 Region and has a disaster recovery requirement that the database be available in another Region with minimal disruption to the database operations is to deploy Aurora cross-Region read replicas. Aurora cross-Region read replicas are secondary Aurora clusters that are created in a different AWS Region from the primary Aurora cluster, and are kept in sync with the primary cluster using physical replication. The company can use Aurora cross-Region read replicas to improve the availability and durability of the database, as well as to reduce the recovery time objective (RTO) and recovery point objective (RPO) in case of a regional disaster. Performing an Aurora Multi-AZ deployment, creating Amazon EBS volume snapshots for Aurora and copying them to another Region, and deploying Aurora Replicas are not the best solutions for this requirement. An Aurora Multi-AZ deployment is a configuration that creates one or more Aurora Replicas within the same AWS Region as the primary Aurora cluster, and provides automatic failover in case of an Availability Zone outage. However, this does not provide cross-Region disaster recovery. Creating Amazon EBS volume snapshots for Aurora and copying them to another Region is a manual process that requires stopping the database, creating the snapshots, copying them to the target Region, and restoring them to a new Aurora cluster. This process can cause significant downtime and data loss. Deploying Aurora Replicas is a configuration that creates one or more secondary Aurora clusters within the same AWS Region as the primary Aurora cluster, and provides read scaling and high availability. However, this does not provide cross-Region disaster recovery.

Deploying the application by using multiple Availability Zones is the best way to increase resilience for the application. According to the Amazon RDS User Guide, "Amazon RDS provides high availability and failover support for DB instances using Multi-AZ deployments. In a Multi-AZ deployment, Amazon RDS automatically provisions and maintains a synchronous standby replica in a different Availability Zone. The primary DB instance is synchronously replicated across Availability Zones to a standby replica to provide data redundancy, eliminate I/O freezes, and minimize latency spikes during system backups."4 Deploying a copy of the application in another AWS account, using multiple VPCs, or using multiple subnets do not provide the same level of resilience as using multiple Availability Zones.