# `AWSSupport-TroubleshootLambdaS3Event`
<a name="automation-aws-troubleshootlambdas3event"></a>

 **Description** 

 The `AWSSupport-TroubleshootLambdaS3Event` runbook provides an automated solution for the procedures outlined in the AWS Knowledge Center articles [Why doesn't my Amazon S3 event notification trigger my Lambda function? ](https://aws.amazon.com/premiumsupport/knowledge-center/lambda-configure-s3-event-notification/) and [ Why do I get the error "Unable to validate the following destination configurations" when creating an Amazon S3 event notification to trigger my Lambda function? ](https://aws.amazon.com/premiumsupport/knowledge-center/lambda-invoke-error-s3-bucket-permission/) This runbook helps you identify why an Amazon Simple Storage Service (Amazon S3) event notification failed to trigger the AWS Lambda function you specified. If the runbook output suggests validating and configuring your Lambda function concurrency, see [Asynchronous invocation](https://docs.aws.amazon.com/lambda/latest/dg/invocation-async.html) and [AWS Lambda Function scaling](https://docs.aws.amazon.com/lambda/latest/dg/scaling.html) . 

 [Run this Automation (console)](https://console.aws.amazon.com/systems-manager/automation/execute/AWSSupport-TroubleshootLambdaS3Event) 

**Document type**

Automation

**Owner**

Amazon

**Platforms**

Linux, macOS, Windows

**Parameters**
+ AutomationAssumeRole

  Type: String

  Description: (Optional) The Amazon Resource Name (ARN) of the AWS Identity and Access Management (IAM) role that allows Systems Manager Automation to perform the actions on your behalf. If no role is specified, Systems Manager Automation uses the permissions of the user that starts this runbook.
+ LambdaFunctionArn

  Type: String

  Description: (Required) The ARN of the Lambda function that the Amazon S3 event notification triggers.
+ S3BucketName

  Type: String

  Description: (Required) The name of the Amazon S3 bucket whose event notifications triggers the Lambda function. 

**Required IAM permissions**

The `AutomationAssumeRole` parameter requires the following actions to use the runbook successfully.
+  `lambda:GetPolicy` 
+  `s3:GetBucketNotification` 

 **Document Steps** 
+  `aws:executeScript` - Runs the script to validate configuration settings for the Amazon S3 event notification. Validates the resource-based IAM policy for your Lambda function, and generates an AWS Command Line Interface (AWS CLI) command to add the needed permissions if the required permissions are missing from the policy. Validates other Lambda functions resource policies which are part of event notifications for the same S3 bucket and generates an AWS CLI command as output if the required permissions are missing. 

 **Outputs** 

lambdaS3Event.output