To invoke a Lambda integration, API Gateway must have the required permissions. You can use a resource-based policy or an IAM role to grant API Gateway permissions to invoke a Lambda function. To learn more, see AWS Lambda Permissions in the * AWS Lambda Developer Guide*.
API Gateway might not generate logs and metrics in the following cases:
413 Request Entity Too Large errors Excessive 429 Too Many Requests errors 400 series errors from requests sent to a custom domain that has no API mapping 500 series errors caused by internal failures