ONNX Runtime ONNXRuntimeError: [ONNXRuntimeError] : 21 : FAIL : Session initialization failed

What is ONNX Runtime ONNXRuntimeError: [ONNXRuntimeError] : 21 : FAIL : Session initialization failed

Understanding ONNX Runtime

ONNX Runtime is a high-performance inference engine for machine learning models in the Open Neural Network Exchange (ONNX) format. It is designed to accelerate the deployment of machine learning models across various platforms and devices. ONNX Runtime supports a wide range of hardware accelerators, making it a versatile choice for developers looking to optimize their model inference.

Identifying the Symptom

When working with ONNX Runtime, you might encounter the following error message: ONNXRuntimeError: [ONNXRuntimeError] : 21 : FAIL : Session initialization failed. This error indicates that the session, which is responsible for managing the execution of the model, could not be initialized.

Common Observations

The error occurs during the model loading phase.The application may crash or fail to proceed with inference tasks.Logs may not provide detailed information about the underlying issue.

Exploring the Issue

The error code 21 in ONNX Runtime signifies a failure in session initialization. This can be attributed to several factors, including incorrect session options, insufficient system resources, or compatibility issues with the model or runtime environment.

Potential Causes

Incorrect configuration of session options such as execution providers or optimization levels.Insufficient memory or CPU resources on the host machine.Incompatibility between the ONNX model version and the ONNX Runtime version.

Steps to Resolve the Issue

To address the session initialization failure, follow these steps:

Step 1: Review Session Options

Ensure that the session options are correctly configured. Check the execution providers and optimization levels. For example:

import onnxruntime as ortsession_options = ort.SessionOptions()session_options.execution_mode = ort.ExecutionMode.ORT_SEQUENTIALsession_options.graph_optimization_level = ort.GraphOptimizationLevel.ORT_ENABLE_EXTENDED

Refer to the ONNX Runtime documentation for more details on configuring session options.

Step 2: Check System Resources

Verify that your system has adequate resources to run the model. Monitor CPU and memory usage using tools like top or htop on Linux, or Task Manager on Windows. Consider closing other applications to free up resources.

Step 3: Validate Model and Runtime Compatibility

Ensure that the ONNX model is compatible with the version of ONNX Runtime you are using. You can check the model's opset version and compare it with the supported opset versions in the ONNX Runtime documentation.

Step 4: Reinitialize the Session

After making the necessary adjustments, attempt to reinitialize the session:

session = ort.InferenceSession("your_model.onnx", session_options)

If the issue persists, consider updating ONNX Runtime to the latest version or checking for any known issues in the ONNX Runtime GitHub repository.

Conclusion

By carefully reviewing session options, ensuring sufficient system resources, and validating model compatibility, you can effectively resolve the session initialization failure in ONNX Runtime. For further assistance, consult the official ONNX Runtime documentation or seek help from the community forums.