Testing and Troubleshooting (1/3)
How do you debug a failing Lambda function?
    Debugging AWS Lambda Function Failures

    Debugging a failing AWS Lambda function involves identifying the root cause using logs, error messages, and tracing tools. AWS provides integrated services like CloudWatch and X-Ray to assist with monitoring, logging, and tracing, making it easier to locate and fix issues.

    Steps to Debug Lambda Failures
    • Check CloudWatch Logs for error stack traces, console output, and custom logs.
    • Look for metrics like Invocation, Error, Throttles, and Duration in CloudWatch Metrics.
    • Use AWS X-Ray to trace requests and identify latencies or downstream errors.
    • Review environment variables and function configuration (timeout, memory, IAM permissions).
    • Manually invoke the function using test events in the AWS Console to reproduce the error.
    • Enable active tracing and log retention policies for better observability.
    • Examine Dead Letter Queues (DLQs) for failed asynchronous events.
    Common Debugging Tools
    • Amazon CloudWatch Logs
    • Amazon CloudWatch Metrics
    • AWS X-Ray
    • Lambda Destinations (for async failures)
    • AWS CLI and AWS SDKs (for testing and troubleshooting)
    Example: View CloudWatch Logs Using AWS CLI