RequestTooLargeException vs RequestEntityTooLargeException

[erjiang]

Please fill out the sections below to help us address your issue.

Version of AWS SDK for Go?

1.27.4

Version of Go (go version)?

1.13.5

What issue did you see?

I tried to filter errors coming from Invoke for "RequestTooLargeException" but I actually got the error "RequestEntityTooLarge" exception:

2020/01/15 14:51:45 Error invoking lambda function
2020/01/15 14:51:45 RequestEntityTooLargeException: Request must be smaller than 6291456 bytes for the InvokeFunction operation
        status code: 413, request id: 4f90b35e-c583-4c6e-bccb-9956291dd896

My error handling code looked like:

log.Println("Error invoking lambda function")
log.Println(err)
awsErr, ok := err.(awserr.Error)
if ok && awsErr.Code() == lambda.ErrCodeRequestTooLargeException {
	log.Fatal("Request too large") // never gets called, because the error codes do not match
}

The SDK defines lambda.ErrCodeRequestTooLargeException, but not lambda.ErrCodeRequestEntityTooLargeException. So, am I looking in the wrong place for the error code constant? What's the difference between RequestTooLargeException and RequestEntityTooLargeException? (The descriptions seem to describe the same thing.)

Workaround was just to use a string instead of referencing a constant from the package.

[jasdel]

Thanks for reaching out @erjiang. It looks like the RequestEntityTooLargeException is an error that the AWS Lambda API does not model in their API definition. The SDKs are built from these definitions and explains why you didn't see that error code in the SDK.

The best way to workaround this issue is to define a constant in your application to compare against the RequestEntityTooLargeException error code.

With that said, Creating a post on the AWS Lambda forums letting them known about the issue would be helpful.

[jasdel]

Do you have example code that is receiving this error message? This will help investigate this issue with the Lambda service team.

The RequestEntityTooLargeException exception looks to be an exception from the IoT Dataplane service, not Lambda. Is it possible the application is mistakenly using a IoT dataplane client instead of Lambda for this location the error is printed?

[erjiang]

I did find the RequestEntityTooLargeException defined in the IoT files, but my code only touches lambda.

Here's my code:

// in init function:

client = lambda.New(sess, &aws.Config{Region: aws.String("us-east-1")})

	// aws go sdk lambda: https://docs.aws.amazon.com/sdk-for-go/api/service/lambda/
	result, err := client.Invoke(&lambda.InvokeInput{FunctionName: aws.String(lambdaName), Payload: payload, LogType: aws.String("Tail")})
	if err != nil {
		awsErr, ok := err.(awserr.Error)
		// this exception is triggered if user uploads a large file.
		// TODO: don't bother sending the request to lambda if it's too big? And
		// figure out an alternate way to do file uploads.
		if ok && (awsErr.Code() == "RequestEntityTooLargeException" || awsErr.Code() == "RequestTooLargeException") {
			w.WriteHeader(413)
			fmt.Fprintf(w, "Error 413: Upload too large")
		} else {
			w.WriteHeader(502)
			fmt.Fprintf(w, "Error 502: There was an error processing this request")
		}
		log.Println("Error invoking lambda function")
		log.Println(err)
		return
	}

as you can see I ended up just matching on strings, and also threw in a check against "RequestTooLargeException" in case the API changes.

[vudh1]

P70312107

[ashishdhingra]

Contacted service team for an update. Awaiting response.

[ashishdhingra]

Followed with service team again. RequestEntityTooLargeException is not modeled per Invoke API documentation and AWS model.

[ashishdhingra]

Contacted service team for an update. Awaiting response.

[ashishdhingra]

We have opened product feature request with the service team. As of now, we do not have ETA on when this would be implemented. It should be reviewed by service team along with other priority items. Since no action is required from our side (SDK), closing this issue.

[github-actions]

This issue is now closed.

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