Category: Elastic Load Balancer

How to access Load Balancer logs

AWS provides access logs for Elastic Load Balancers (ELB), allowing you to monitor and analyze traffic patterns. Below are general steps to access and view ELB access logs:

Amazon ELB Access Logs:

  1. Navigate to the EC2 Console:
    • Open the AWS EC2 Console.
  2. Select Load Balancers:
    • In the left navigation pane, choose “Load Balancers” under the “Load Balancing” section.
  3. Choose Your Load Balancer:
    • Click on the name of the load balancer for which you want to access logs.
  4. View Access Logs:
    • In the “Description” tab, look for the “Attributes” section.
    • Check if the “Access logs” attribute is set to “Enabled.”
  5. Access Logs Location:
    • If access logs are enabled, you can find them in an S3 bucket specified in the “S3 bucket” field.
  6. Navigate to S3 Bucket:
    • Open the AWS S3 Management Console.
    • Access the S3 bucket mentioned in the “S3 bucket” field.
  7. Access Log Files:
    • Inside the S3 bucket, you should find log files with a naming convention like <load-balancer-name>/<YYYY>/<MM>/<DD>/....
    • Download or view the log files to analyze the access logs.

AWS CLI:

You can also use the AWS Command-Line Interface (CLI) to access ELB access logs:

# Replace <your-load-balancer-name> and <your-s3-bucket-name> with your actual values

aws s3 cp s3://<your-s3-bucket-name>/<your-load-balancer-name>/<path-to-log-file> .

This command downloads the specified log file to the current directory.

Analyzing Access Logs:

Access logs typically include information such as client IP addresses, request timestamps, response status codes, and more. You can use tools like AWS Athena, Amazon CloudWatch Logs Insights, or other log analysis tools to query and visualize the logs.

Remember to adjust the steps based on the specific type of load balancer you are using (Application Load Balancer, Network Load Balancer, or Classic Load Balancer). Always refer to the official AWS documentation for the most accurate and up-to-date information.

These logs are much helpful if you are looking from which instance the request is coming.