Debugs AWS Lambda function timeout failures by systematically analyzing function configuration, CloudWatch logs and metrics, VPC/networking, cold starts, memory constraints, and downstream dependencies to identify root causes with actionable fixes. Use when a Lambda function is timing out or approaching its timeout limit.
Install
npx skills add https://github.com/aws/agent-toolkit-for-aws --skill debugging-lambda-timeoutsDebugging Lambda Timeouts
Overview
Domain expertise for systematically investigating AWS Lambda function timeout failures by analyzing function configuration, CloudWatch logs, metrics, dependencies, cold start patterns, and code. Identifies common causes such as insufficient timeout settings, external service delays, database connection issues, memory constraints, and inefficient code patterns, then provides prioritized recommendations.
Debug a Lambda timeout
To investigate and resolve Lambda timeout issues, follow the procedure exactly. See Lambda timeout debugging procedure.
The procedure collects function configuration, CloudWatch metrics and logs, dependency analysis, and cold start patterns. If Lambda code is provided, it also reviews the code for timeout-prone patterns. Results are compiled into a structured debugging report with prioritized recommendations.
Troubleshooting
Function not found
Verify the function name and region. Use aws lambda list-functions --region <region>
to list available functions.
No logs available
The function may not have been invoked recently or logging may be disabled. Check the function's log group configuration and invocation metrics.
Access denied errors
Verify AWS credentials have permissions for Lambda, CloudWatch Logs, and CloudWatch Metrics. See the full procedure for details.
Log query time range issues
If CloudWatch Logs Insights queries fail with time range errors, reduce the analysis window or check log group retention settings. See the full procedure for details.