Amazon Web Services Updated SOA-C02 Exam Questions and Answers by ivy-rae

To troubleshoot high CPU utilization during load testing without scaling out, the SysOps administrator should suspend the Launch and Terminate process types in the Auto Scaling group.

Suspending Processes:

Suspending the Launch and Terminate processes will temporarily stop the Auto Scaling group from adding or removing instances, allowing for troubleshooting without automatic scaling interruptions.

This ensures that the root cause of the high CPU utilization can be investigated without the Auto Scaling group launching additional instances.

Steps to Suspend Processes:

Go to the Auto Scaling group in the AWS Management Console.

Select the group and choose the "Suspend Processes" option.

Suspend the Launch and Terminate processes.

After troubleshooting, resume the processes to re-enable scaling.

To address the issue of slow startup times during unexpected traffic surges, a warm pool for the Auto Scaling group is an effective solution:

Warm Pool Concept: A warm pool allows you to maintain a set of pre-initialized or partially initialized EC2 instances that are not actively serving traffic but can be quickly brought online when needed.

Management of Instances: Instances in the warm pool can be kept in a stopped state and then started much more quickly than launching new instances, as the machine-specific data caches are already created.

Scalability and Responsiveness: During a surge in traffic, especially unpredictable ones like those triggered by advertisements, instances from the warm pool can be rapidly activated to handle the increased load, ensuring that the application remains responsive without the typical delays associated with boot processes.

This method significantly reduces the time to scale out by utilizing pre-warmed instances, enhancing the application's ability to cope with sudden and substantial increases in traffic.

The rejected traffic in the flow logs is due to the network ACL associated with the subnet not allowing outbound traffic for the ephemeral port range.

Network ACLs:

Network ACLs act as a firewall for controlling traffic in and out of one or more subnets.

By default, NACLs allow all inbound and outbound traffic, but custom NACLs require specific rules to allow traffic.

Ephemeral Ports:

Ephemeral ports are temporary ports used for client-side communication. The default range is 1024-65535.

Ensure that the network ACL allows outbound traffic on these ports.

Steps to Resolve:

Check the network ACL rules for the associated subnet.

Add outbound rules to allow traffic from the ephemeral port range (1024-65535).

References:

Amazon VPC Network ACLs

AWS Compute Optimizer provides recommendations for optimizing the performance and cost of your AWS resources, including Lambda functions.

Steps:

Enable AWS Compute Optimizer:

Open the AWS Compute Optimizer console.

Choose "Get started".

Enable Compute Optimizer for your account.

View Lambda Function Recommendations:

After enabling Compute Optimizer, allow some time for data collection and analysis.

Navigate to the "Lambda Function Recommendations" section in the Compute Optimizer console.

Review the recommendations for your Lambda functions, which may include adjustments to memory size or other configurations to improve performance and reduce costs.

Export Recommendations:

In the Compute Optimizer console, you can export the recommendations to a CSV file for further analysis and action.

References:

AWS Compute Optimizer

Optimizing Lambda Function Configurations