At the time of the 4XX errors, how can an Administrator obtain information about who originated these requests?
If ELB access logs have been enabled, the information can be retrieved from the S3 bucket
Contact AWS Support to obtain application logs from the deleted instances
Amazon S3 always keeps a backup of application logs from EC2 instances. Retrieve these logs for analysis
Use AWS Trusted Advisor to obtain ELB access logs
Explanations:
If ELB access logs are enabled, they contain detailed information about incoming requests to the load balancer, including the originating IP addresses and request details. These logs are stored in an S3 bucket.
AWS Support cannot retrieve application logs from deleted EC2 instances. Once the instances are terminated, their local logs are lost unless they were stored externally (e.g., in Amazon S3 or CloudWatch).
Amazon S3 does not automatically back up application logs from EC2 instances. If logs were not explicitly stored in S3 or another logging service, they are not recoverable after the instances are deleted.
AWS Trusted Advisor does not provide ELB access logs. Trusted Advisor offers recommendations on AWS best practices but does not store or provide detailed request logs.
I compute that the answer is:
If ELB access logs have been enabled, the information can be retrieved from the S3 bucket