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

Content-MD5 Header:

The Content-MD5 header provides an MD5 checksum of the object being uploaded. Amazon S3 uses this checksum to verify the integrity of the object.

Steps:

When uploading an object to S3, calculate the MD5 checksum of the object.

Include the Content-MD5 header with the base64-encoded MD5 checksum value in the upload request.

This ensures that S3 can detect if the object is corrupted during the upload process.

Step-by-Step Explanation:

Understand the Problem:

The application on a general-purpose EC2 instance experiences performance issues during I/O intensive tasks.

High VolumeQueueLength indicates a bottleneck in I/O operations.

Analyze the Requirements:

Improve disk I/O performance to handle intensive read/write operations.

Evaluate the Options:

Option A: Modify the instance type to be storage optimized.

This could help but may not be necessary if increasing IOPS on the EBS volume resolves the issue.

Option B: Deselect Auto-Enable Volume I/O.

This option is not relevant to addressing high VolumeQueueLength.

Option C: Modify the volume properties to increase the IOPS.

Increasing IOPS directly addresses the I/O performance bottleneck.

Option D: Enable enhanced networking.

Enhanced networking improves network performance but not disk I/O performance.

Select the Best Solution:

Option C: Increasing the IOPS of the EBS volume directly addresses the high VolumeQueueLength and improves I/O performance.

References:

Amazon EBS Volume Types

Optimizing EBS Performance

Modifying the volume properties to increase the IOPS ensures that the application can handle intensive read/write operations more effectively.

To count application errors grouped by type across all CloudWatch Logs log groups, use CloudWatch Logs Insights.

Steps:

Access CloudWatch Logs Insights:

Open the CloudWatch console and navigate to Logs Insights.

The most likely reason for being unable to authenticate an AWS CLI call to an AWS service is the absence of an access key. AWS CLI requires an access key and secret key to authenticate requests.

Access Key and Secret Key:

AWS uses access keys to identify and authenticate the identity of the requester.

Ensure that the AWS CLI is configured with a valid access key and secret key.

Check AWS CLI Configuration:

Use the aws configure command to set up the AWS CLI with the necessary credentials.

Verify that the ~/.aws/credentials file contains the correct access key and secret key.

References:

AWS CLI Configuration

Managing Access Keys