General Neuron FAQs

Getting started with Neuron FAQs

Q: How can I get started?

You can start your workflow by training your model in one of the popular ML frameworks using EC2 GPU instances, or alternatively download a pre-trained model. Once the model is trained to your required accuracy, you can use the ML frameworks’ API to invoke Neuron, to re-target(i.e. compile) the model for execution on Inferentia. The compilation is done once and its artifacts can then be deployed at scale. Once compiled, the binary can be loaded into one or more chips to start service inference calls.

In order to get started quickly, you can use AWS Deep Learning AMIs that come pre-installed with ML frameworks and the Neuron SDK. For a fully managed experience, you can use Amazon SageMaker to seamlessly deploy and accelerate your production models on ml.inf1 instances.

For customers who use popular frameworks like TensorFlow, MXNet and PyTorch, a guide to help you get started with frameworks is available at:

You can also visit QuickStart.

Q: How do I select which Inf1 instance size to use?

The decision as to which Inf1 instance size to use is based upon the application and its performance/cost targets. To assist, TensorBoard profiling will show actual results when executed on a given instance. A guide to this process is available here: Getting Started: TensorBoard-Neuron.

As a rule of thumb, we encourage you to start with inf1.xlarge and test your model. For example, many computer vision models require pre/post processing that consume CPU resources and such models will get higher throughput on the inf1.2xlarge that provides higher ratio of vCPU/Chip.

We encourages you try out all the Inf1 instance sizes with your specific models, until you find the best size for your application needs.

General

Q: What ML models types and operators are supported by AWS Neuron?

AWS Neuron includes a compiler that converts your trained machine learning models to a binary object for execution (aka Neuron Executable File Format or a NEFF file in short). The Neuron compiler supports many commonly used machine learning operators used in computer vision, natural language processing, recommender engines and more. A list of supported ML operators and supported inputs are in Neuron Supported operators .

It’s important to mention that to get good performance doens’t require all of the model operators to run on the chip. In many cases, some of the operators will continue to run on the instance CPUs, like the case of embeddings or image pre-processing, and will still provide a compelling end to end performance. We call this approach auto-partitioning, where the Neuron compiler optimizes the model execution based on operators that are most suitable to run on the CPU or the chip.

We constantly add more operators based on customers’ feedback.

Q: Why is a compiler needed, and how do I use it?

The Neuron compiler converts from a framework level Neural Network graph, with operators like convolution and pooling, into a hardware-specific instruction set, builds the schedule for execution of these instructions, and converts the model parameters into format that the chip can consume. The supported input formats include TensorFlow, PyTorch, and MXNet. The output from the compiler is a Neuron Executable File Format (NEFF) artifact. The NEFF contains a combination of binary code, the model parameters, and additional meta-data needed by the Neuron runtime and profiler.

Q: I am using a ML framework today – what will change for me to use this?

To use Inferentia within the Inf1 instances, the developer need to perform one-time compilation of the pre-trained model to generate a NEFF, and use this as the inference model in fleet of Inf1 instances.

Q: What is a NeuronCore Pipeline ? and How do I take advantage of it?

A NeuronCore Pipeline is a unique technique to shard a specific Neural Network across multiple NeuronCores, to take advantage of the large on-chip cache instead of moving data in and out of external memory. The result is an increased throughput and reduce latency typically important for real-time inference applications. All Inf1 instances support it, and the Inf1 instances with multiple Inferentia accelerators, such as inf1.6xlarge or inf1.24xlarge support it thanks to the fast chip-to-chip interconnect.

Developers can choose to use NeuronCore Pipeline mode during compile stage, with an opt-in flag. Neuron Compiler provides further details.

Q: NeuronCores, NeuronCore Groups and NeuronCore Pipelines: What do they do?

Each Inferentia chip has four compute engines called NeuronCores. A NeuronCore Group is a way to aggregate NeuronCores to increase hardware utilization and assign models with the right compute sizing for a specific application. If you want to run mutliple models in parallel, you can assign different models to separate NeuronCore Groups. A model compiled to use multiple NeuronCores in a NeuronCore Pipeline can be assigned to a NeuronCore Group with enough NeuronCores to load into. Finally- it is also possible for sets of Inferentia devices to be mapped to separate Neuron Runtimes. Neuron Features section has more information and examples.

Q: Can I use TensorFlow networks from tfhub.dev as-is ? if not, what should I do?

Yes. Models format can be imported into TensorFlow, either as a standard model-server, in which case it appears as a simple command line utility, or via the Python based TensorFlow environment. The primary additional step needed is to compile the model into Inferentia NEFF format.

Troubleshooting FAQs

Q: Performance is not what I expect it to be, what’s the next step?

Please check our Performance Optimization section on performance tuning and other notes on how to use pipelining and batching to improve performance!

Q: Do I need to worry about size of model and size of inferentia memory? what problems can I expect to have?

Errors like this will be logged and can be found as shown Using Neuron GatherInfo Tool to collect debug and support information.

Q: How can I debug / profile my inference request?

See Getting Started: TensorBoard-Neuron

Contributing Guidelines FAQs

Whether it’s a bug report, new feature, correction, or additional documentation, we greatly value feedback and contributions from our community.

Please read through this document before submitting any issues or pull requests to ensure we have all the necessary information to effectively respond to your bug report or contribution.

Q: How to reporting Bugs/Feature Requests

We welcome you to use the GitHub issue tracker to report bugs or suggest features.

When filing an issue, please check existing open, or recently closed, issues to make sure somebody else hasn’t already reported the issue. Please try to include as much information as you can. Details like these are incredibly useful:

  • A reproducible test case or series of steps

  • The version of our code being used

  • Any modifications you’ve made relevant to the bug

  • Anything unusual about your environment or deployment

Q: Contributing via Pull Requests

Contributions via pull requests are much appreciated. Before sending us a pull request, please ensure that:

  1. You are working against the latest source on the master branch.

  2. You check existing open, and recently merged, pull requests to make sure someone else hasn’t addressed the problem already.

  3. You open an issue to discuss any significant work - we would hate for your time to be wasted.

To send us a pull request, please:

  1. Fork the repository.

  2. Modify the source; please focus on the specific change you are contributing. If you also reformat all the code, it will be hard for us to focus on your change.

  3. Ensure local tests pass.

  4. Commit to your fork using clear commit messages.

  5. Send us a pull request, answering any default questions in the pull request interface.

  6. Pay attention to any automated CI failures reported in the pull request, and stay involved in the conversation.

GitHub provides additional document on forking a repository and creating a pull request.

Q: How to find contributions to work on

Looking at the existing issues is a great way to find something to contribute on. As our projects, by default, use the default GitHub issue labels (enhancement/bug/duplicate/help wanted/invalid/question/wontfix), looking at any ‘help wanted’ issues is a great place to start.

Q: What is the code of conduct

This project has adopted the Amazon Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opensource-codeofconduct@amazon.com with any additional questions or comments.

Q: How to notify for a security issue

If you discover a potential security issue in this project we ask that you notify AWS/Amazon Security via our vulnerability reporting page. Please do not create a public github issue.

Q: What is the licensing

See the license-dicumentation and license-summary-docs-samples files for our project’s licensing. We will ask you to confirm the licensing of your contribution.

We may ask you to sign a Contributor License Agreement (CLA) for larger changes.