Handle "ServiceException" in AWS Step Functions

Correct Answer - C.

Any state under step functions can encounter runtime errors.

Errors can happen for various reasons:

Task failures (for example, an exception in a Lambda function)

AWS Lambda can occasionally experience transient service errors.

In this case, invoking Lambda results in a 500 error, such as

ServiceException.

,

AWSLambdaException.

, or

SdkClientException.

.

By default, when a state reports an error, AWS Step Functions causes the execution to fail entirely.

For errors such as “ServiceException”, the best practice is to Retry invoking the Lambda function.

Within a Retry Code, the “ErrorEquals” field is the required string that matches error names & all other fields are optional.

Option A is incorrect as the Lambda Catch code is only used after the function performs several retries and ErrorEquals & Next are required strings.

Option B is incorrect as the BackoffRate field is optional in Lambda Retry code & if not specified, the default value of 2.0 is considered.

Option D is incorrect as the Lambda Catch code is only used after the function performs several retries.

ResultPath is an optional field in a Catch Code, ErrorEquals & Next are required strings.

For more information on troubleshooting Lambda Function errors, refer to the following URL-

https://docs.aws.amazon.com/step-functions/latest/dg/concepts-error-handling.html https://docs.aws.amazon.com/step-functions/latest/dg/bp-lambda-serviceexception.html

When a Lambda function generates an error, you can use AWS Step Functions to handle it by specifying the appropriate response to the error. In this case, the error is a "ServiceException," and the best practice for handling it under AWS Step Functions is to use a Lambda Catch code block with only "ErrorEquals" string.

Here's an explanation of each answer choice:

A. Use Lambda Catch code with only “ErrorEquals” string. This is the correct answer. With this approach, you can catch any error that matches the specified "ErrorEquals" string. In this case, the string would be "ServiceException," which would allow you to handle this specific error.

B. Use Lambda Retry code with only “BackoffRate” string This answer choice is incorrect because it doesn't address the specific error that the Lambda function is generating. Additionally, "BackoffRate" is a parameter used to specify the amount of time between retries, not the type of error to retry on.

C. Use Lambda Retry code with only “ErrorEquals” string. This answer choice is incorrect because it doesn't provide a fallback mechanism in case the retries fail. It's better to use a Lambda Catch code block to handle the error and provide a fallback response.

D. Use Lambda Catch code with only “ResultPath” string. This answer choice is incorrect because "ResultPath" is used to specify the location where the output of the Lambda function is stored, not the type of error to handle.

In summary, the best practice for handling a "ServiceException" error generated by a Lambda function under AWS Step Functions is to use a Lambda Catch code block with only "ErrorEquals" string.