You are in charge of deploying an application hosted on an EC2 Instance and sitting behind an Elastic Load Balancer. You have been requested to monitor the incoming client connections to the Elastic Load Balancer. Which of the below options can suffice this requirement?

Answer options:

A.Use AWS CloudTrail with your load balancer.
B.Enable access logs on the load balancer.
C.Use a CloudWatch Logs Agent by installing on EC2.
D.Create a custom metric CloudWatch filter on your load balancer.

Answer – B
The AWS Documentation mentions the following.
Elastic Load Balancing provides access logs that capture detailed information about requests sent to your load balancer. Each log contains information such as the time the request was received, the client`s IP address, latencies, request paths, and server responses. You can use these access logs to analyze traffic patterns and troubleshoot issues.
Option A is INCORRECT because CloudTrail captures all API calls for Elastic Load Balancing as events. This is not the recommended approach to monitoring incoming connections to the ELB.Option B is CORRECT. Each log contains information such as the time the request was received, the client`s IP address, latencies, request paths, and server responses. You can use these access logs to analyze traffic patterns and to troubleshoot issues.
Option C is invalid since the Logs agents are installed on EC2 Instances and not on the ELB.Option D is invalid since the metrics will not provide detailed information on the incoming connections.
For more information on Application Load balancer Logs, please refer to the below link-
https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-access-logs.html
Please refer to page 99 on the below link-
https://docs.aws.amazon.com/elasticloadbalancing/latest/application/elb-ag.pdf