Verifying Arnold UBL Usage in AWS Deadline Cloud: A Story of How Job SUCCEEDED Status Alone Wasn't Enough to Tell

Introduction

After configuring Arnold's Usage-Based Licensing (UBL) on AWS Deadline Cloud's Customer-Managed Fleet (CMF), it is tempting to consider the setup complete once a test job reaches SUCCEEDED status and images are output.

However, Arnold renders with watermarks even when it cannot acquire a license. During verification, I encountered a situation where a job that failed to acquire a license completed with exit code 0 and showed as SUCCEEDED in Deadline Cloud. Additionally, for short-duration renders, there were cases where it was not possible to determine license usage from CloudWatch values.

This article introduces how to confirm that a license was actually used after configuring Arnold's UBL on CMF.

What is AWS Deadline Cloud

AWS Deadline Cloud is a service that manages rendering jobs and render farms in the cloud. Customer-Managed Fleet (CMF) is a configuration where jobs are processed by Workers prepared by the user.

What is Arnold

Arnold is a physically-based renderer provided by Autodesk. In 3ds Max, Arnold is used through a plugin called MAXtoA. To process Arnold jobs for 3ds Max in Deadline Cloud, you install 3ds Max and MAXtoA on the Worker and configure it to render using Arnold from the 3ds Max Adaptor.

What is Usage-Based Licensing (UBL)

Usage-Based Licensing (UBL) is a mechanism that allows you to use licenses for software supported by Deadline Cloud, charged based on usage time. When using UBL with Deadline Cloud's CMF, you create a License Endpoint in your VPC to forward license requests from Workers to the Deadline Cloud license server.

Target Audience

• Those configuring Arnold's UBL on Deadline Cloud's CMF
• Those who have had a job succeed but want to confirm whether a UBL license was acquired

References

• Using software licenses with Deadline Cloud
• Connect customer-managed fleets to a license endpoint
• CloudWatch metrics

Issue

When rendering without configuring an Arnold license in my development environment, the job output images and reached SUCCEEDED status. However, a watermark was displayed across the entire image.

Additionally, upon checking the session log, the following warning was output.

rendering with watermarks because of failed authorization

What can be determined from the job status is only whether the rendering process itself succeeded; whether Arnold successfully acquired a license must be verified through a separate method.

After this, I configured UBL in a separate environment and ran a minimal Arnold job.

This job also reached SUCCEEDED status, and there were no authorization failure warnings in the logs. However, the rendering completed in under one second, and CloudWatch's LicensesInUse remained at 0. To directly confirm UBL usage, it is necessary to observe LicensesInUse=1, but this could not be confirmed in this attempt. The output was a 160×120 pixel fully transparent image with nothing rendered. Looking at this image alone, it was not possible to determine whether the watermark had disappeared.

An image where all pixels were transparent, making it impossible to determine the presence or absence of a watermark

Solution

Therefore, I used an image where the presence or absence of a watermark could be confirmed, extended the rendering duration to approximately 7 minutes, and checked LicensesInUse during that time.

The results were verified using the following 3 items.

Checking CloudWatch

Deadline Cloud outputs the LicensesInUse metric to the AWS/DeadlineCloud namespace. In CMF, you can filter by LicenseEndpointId for the License Endpoint and Product for the metered product.

This time, I retrieved a separate series specifying only LicenseEndpointId and a series specifying only Product=arnold. The two dimensions were not specified simultaneously. Both changed from 0 before the start to 1 during rendering.

The Product=arnold series showed LicensesInUse=1, confirming that an Arnold license session was used.

Checking Logs and Images

In the session log, I confirmed that ADSKFLEX_LICENSE_FILE was pointing to the target License Endpoint, and that the authorization failure and watermark-related warnings that appeared without a license were now gone.

The output image allowed objects to be identified, and I visually confirmed the absence of the Arnold watermark.

Logs and images alone cannot independently prove which license path was used. In this verification, LicensesInUse=1 served as direct evidence, while the logs and images confirmed consistency with the target job.

Summary

Arnold may output watermarked images and complete normally even when it cannot acquire a license. Therefore, a Deadline Cloud job reaching SUCCEEDED status alone is not sufficient to confirm that UBL has started being used.

Through the following steps, I was able to confirm that UBL was used during rendering.

1. Ensure sufficient execution time to observe metrics
2. Confirm LicensesInUse=1 in CloudWatch
3. Verify consistency with the target job using session logs and output images

I hope this serves as a useful reference for items to verify before using Arnold's UBL with Deadline Cloud's CMF.