SOA-C02 Question 280
Select 2Your organization has deployed an application behind an Application Load Balancer (ALB) in AWS. Users are reporting intermittent connectivity issues when accessing the application. As an AWS SysOps Administrator, you need to identify the source of the problem. Which log sources can you use to troubleshoot the issue effectively?
- A
VPC Flow Logs
- B
ALB Access Logs
- C
CloudTrail Logs
- D
AWS WAF Web ACL Logs
- E
CloudFront Logs
Show answer and explanation
Correct answers: A, B
Explanation
To troubleshoot intermittent connectivity issues with an application behind an ALB, VPC Flow Logs and ALB Access Logs are the most relevant sources of information. VPC Flow Logs provide insights into network-level traffic flows, while ALB Access Logs offer details about each request that reaches the load balancer. Together, these logs can help identify whether the issue is network-related or application-specific. Other log sources, such as CloudTrail Logs, AWS WAF Web ACL Logs, and CloudFront Logs, are either unrelated to the ALB or only applicable in specific scenarios.
- A. Correct.
VPC Flow Logs capture network traffic information at the subnet or network interface level, which can help you identify if traffic is reaching the ALB. This is critical for diagnosing potential connectivity issues.
- B. Correct.
ALB Access Logs record detailed information about the requests that reach the ALB, including client IP, request path, and response codes. This is directly useful for understanding intermittent connectivity issues.
- C. Incorrect.
CloudTrail Logs track API activity and configuration changes within your AWS account, but they do not provide detailed request or network-level information necessary for identifying connectivity issues.
- D. Incorrect.
AWS WAF Web ACL Logs capture details about HTTP requests inspected by the WAF. While useful for identifying blocked requests based on security rules, they do not provide insights into general connectivity issues.
- E. Incorrect.
CloudFront Logs are specific to CloudFront distributions and would only be relevant if your application were distributed through CloudFront. They are not applicable to an ALB without CloudFront in the architecture.