How to Disable and Re-enable an AWS Lambda Function (Step-by-Step Guide)

Managing the availability of your AWS Lambda functions is essential for maintaining performance, cost control, and operational reliability. While AWS Lambda does not provide a built-in “disable” feature like EC2 or RDS, you can still prevent a function from being triggered and re-enable it later using smart configuration techniques.

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 Step-by-Step: Disabling a Lambda Function

Since AWS Lambda doesn't have a direct "Disable" button, here are effective methods to prevent it from running:

1. Remove or Comment Out Event Source Mappings

For functions triggered by event sources like SQS, DynamoDB, or Kinesis:

• Navigate to Lambda Console > Your Function > Configuration > Triggers.
  
  

• Select the trigger and click “Remove”.
  
  

• Alternatively, if using the AWS CLI:
  
  

aws lambda delete-event-source-mapping --uuid <UUID>

To find the UUID:

aws lambda list-event-source-mappings --function-name <function_name>

2. Disable Scheduled Triggers (Amazon EventBridge / CloudWatch)

For cron-based or rate-based triggers:

• Go to the Amazon EventBridge Console.
  
  

• Find the rule associated with the Lambda.
  
  

• Choose “Disable”.
  
  

Via AWS CLI:

aws events disable-rule --name <rule_name>

3. Detach API Gateway or Other Integrations

If your Lambda is triggered via API Gateway, remove or turn off the integration:

• Open the API Gateway Console.
  
  

• Edit the method, remove the Lambda integration, or set the integration to a mock.
  
  

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 Step-by-Step: Re-enabling a Lambda Function

To resume the function's behavior:

1. Recreate or Reattach Event Source Mapping

Using the AWS CLI:

aws lambda create-event-source-mapping \

  --function-name <function_name> \

  --event-source-arn <source_arn> \

  --starting-position LATEST

Or add the trigger back via the Lambda console under the Triggers section.

2. Enable Scheduled Triggers Again

Using AWS CLI:

aws events enable-rule --name <rule_name>

Or via the console:

• Go to EventBridge > Rules.
  
  

• Choose the rule and click “Enable”.
  
  

3. Re-integrate API Gateway or Other Services

Reconfigure the integration to point to your Lambda function again via:

• API Gateway Console, or
  
  

• Using AWS CLI with put-integration.
  
  

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 Best Practices

• Tag Lambda functions with "Status":"Disabled" when temporarily disabling them.
  
  

• Use IAM condition keys if needed to restrict access programmatically.
  

• Document the reason for disabling in CloudWatch Logs or tagging metadata.