# Best practices

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This page was generated from content adapted from the [AWS Developer Guide](https://github.com/awsdocs/aws-step-functions-developer-guide.git)
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## Use timeouts to avoid stuck executions

* **Note**\
  You can set a timeout for your state machine using the `TimeoutSeconds` field in your Amazon States Language definition. For more information, see [State Machine Structure](https://github.com/kevinslin/aws-reference-notes/blob/main/services/aws_step_functions/amazon-states-language-state-machine-structure.md).

## Use Amazon S3 ARNs instead of passing large payloads

* **Note**\
  After you create this Lambda function, make sure you provide its IAM role the appropriate permission to read from an Amazon S3 bucket. For example, attach the **AmazonS3ReadOnlyAccess** permission to the Lambda function's role.

## Handle Lambda service exceptions

* **Note**\
  Unhandled errors in Lambda are reported as `Lambda.Unknown` in the error output. These include out-of-memory errors and function timeouts. You can match on `Lambda.Unknown`, `States.ALL`, or `States.TaskFailed` to handle these errors. When Lambda hits the maximum number of invocations, the error is `Lambda.TooManyRequestsException`. For more information about Lambda function errors, see [Error handling and automatic retries](https://docs.aws.amazon.com/lambda/latest/dg/invocation-retries.html) in the *AWS Lambda Developer Guide*.