Amazon Web Services SOA-C02 Exam With Confidence Using Practice Dumps

Using ALB health checks in the Auto Scaling group will provide more accurate health monitoring and replace instances if they are unhealthy.

ALB Health Checks: Configure health checks based on HTTP response codes, which will detect application-level issues causing the HTTP 500 errors and replace instances as needed.

EC2 vs. ALB Health Checks: EC2 status checks only verify instance hardware and OS, not the application’s responsiveness. By using ALB health checks, Auto Scaling can remove instances that are failing at the application level, thus preventing users from receiving 500 errors.

Replacing the ALB with a Network Load Balancer does not address HTTP 500 errors, and enabling session affinity does not resolve application health issues. The CloudWatch agent would not provide the required health check functionality for automated instance replacement.

To troubleshoot connectivity issues for an EC2 instance that's not accessible via RDP after moving to a private subnet, VPC flow logs are the most direct and useful tool. VPC flow logs capture information about the IP traffic going to and from network interfaces in your VPC, enabling you to identify whether the traffic to the EC2 instance is being allowed or rejected. Setting up flow logs for the EC2 instance’s network interface will help pinpoint any blocks or drops in traffic that could be causing the timeout error. Option C is the correct action as it directly investigates the traffic flow, which is crucial for resolving connectivity issues. AWS documentation on VPC flow logs provides further details VPC Flow Logs.

To reduce latency in data transfer among EC2 instances, especially in high-performance computing (HPC) applications or applications requiring low network latency, using a placement group is the best approach:

Understanding Placement Groups:

A placement group in Amazon EC2 is a logical grouping of instances within a single Availability Zone. Using placement groups, you can achieve low-latency network performance necessary for tightly coupled node-to-node communication.

Types of Placement Groups:

Cluster Placement Group: Instances are physically located close together in the same Availability Zone to provide low-latency network performance.

Partition Placement Group: Instances are divided into logical segments called partitions, reducing the likelihood of simultaneous failures.

Spread Placement Group: Instances are placed on distinct underlying hardware to reduce correlated failures.

Creating and Using a Placement Group:

You can create a placement group using the AWS Management Console, AWS CLI, or AWS SDKs.

When launching instances, specify the placement group to ensure they are launched within the same group.

aws ec2 create-placement-group --group-name my-placement-group --strategy cluster

aws ec2 run-instances --image-id ami-12345678 --count 4 --instance-type c5.large --placement GroupName=my-placement-group

Relocating Existing Instances:

Stop the instances, modify the placement group settings, and then restart them. Note that not all instance types are supported within placement groups, so check the documentation for compatibility.

Placement Groups

Cluster Instances for Low-Latency