Implementing the Model Fault Injection and Evaluation

Overview

In the past decade, artificial intelligence has become ubiquitous in many applications. It is also being increasingly deployed in safety critical or security critical applications such as automatic driving, intelligent security, intelligent medical treatment and so on. In these domains, it is critical to ensure the reliability of the AI models and its implementation as faults can lead to loss of life and property.

In order to ensure the reliability and availability of AI model under various fault scenarios, it is important to strictly test and verify its components. This module can simulate various fault scenarios and evaluation of model reliability.

The following is a simple example showing the overall process of model fault injection and evaluation:

1. Download a public dataset.

2. Prepare both datasets and pre-train models.

3. Call the fault injection module.

4. View the execution result.

You can obtain the complete executable code at https://gitee.com/mindspore/mindarmour/blob/master/examples/reliability/model_fault_injection.py

Preparations

Ensure that the MindSpore is correctly installed. If not, install MindSpore by following the Installation Guide.

Downloading the Dataset

The MNIST database of handwritten digits has a training set of 60,000 examples, and a test set of 10,000 examples.

Download the dataset at http://yann.lecun.com/exdb/mnist/

Decompress the downloaded dataset to a local path. The directory structure is as follows:

- data_path
    - train
        - train-images-idx3-ubyte
        - train-labels-idx1-ubyte
    - test
        - t10k-images-idx3-ubyte
        - t10k-labels-idx1-ubyte

Downloading the Checkpoint File

Download checkpoint file or just trained your own checkpoint.

Download the checkpoint file at https://www.mindspore.cn/resources/hub/

Importing the Python Library and Modules

Before start, you need to import the Python library.

import numpy as np
import mindspore as ms

from mindspore.train import Model
from mindarmour.reliability import FaultInjector
from examples.common.networks.lenet5.lenet5_net import LeNet5
from examples.common.dataset.data_processing import generate_mnist_dataset

Constructing the Dataset and Model

Take MNIST dataset and LeNet5 as an example.

Construct MNIST dataset:

DATA_FILE = 'PATH_TO_MNIST/'
ds_eval = generate_mnist_dataset(DATA_FILE, batch_size=64)
test_images = []
test_labels = []
for data in ds_eval.create_tuple_iterator(output_numpy=True):
    images = data[0].astype(np.float32)
    labels = data[1]
    test_images.append(images)
    test_labels.append(labels)
ds_data = np.concatenate(test_images, axis=0)
ds_label = np.concatenate(test_labels, axis=0)

Construct LeNet5:

ckpt_path = 'PATH_TO_CHECKPOINT/'
net = LeNet5()
param_dict = ms.load_checkpoint(ckpt_path)
ms.load_param_into_net(net, param_dict)
model = Model(net)

Setup Parameters and Initialize Fault Injection Module

Setup parameters, the code is as follows:

fi_type = ['bitflips_designated', 'precision_loss']
fi_mode = ['single_layer', 'all_layer']
fi_size = [1, 2]

Initialize fault injection module:

fi = FaultInjector(model=model, fi_type=fi_type, fi_mode=fi_mode, fi_size=fi_size)

The initialization parameters are described as follows:

• model(Model): The model needs to be evaluated.

• fi_type(list): The type of the fault injection which includes bitflips_random(flip randomly), bitflips_designated(flip the key bit), random, zeros, NaN, INF, anti_activation precision_loss etc.

  • bitflips_random: Bits are flipped randomly in the chosen value.

  • bitflips_designated: Specified bit is flipped in the chosen value.

  • random: The chosen value are replaced with random value in the range [-1, 1].

  • zeros: The chosen value are replaced with zero.

  • NaN: The chosen value are replaced with NaN.

  • INF: The chosen value are replaced with INF.

  • anti_activation: Changing the sign of the chosen value.

  • precision_loss: Round the chosen value to 1 decimal place.

• fi_mode(list): There are twe kinds of injection modes can be specified, single_layer or all_layer.

• fi_size(list): The exact number of values to be injected with the specified fault. For zeros, anti_activation and precision_loss fault, fi_size is the percentage of total tensor values and varies from 0% to 100%.

Evaluation

After the module is initialized, call the fault injection function kick_off.

results = fi.kick_off(ds_data, ds_label, iter_times=100)

• ds_data(numpy.ndarray): The data for testing. The fault tolerance of the model will be evaluated on this data.

• ds_label(numpy.ndarray): The label of data, corresponding to the data.

• iter_times(numpy.ndarray): The number of evaluations, which will determine the batch size.

call function metrics, and get summary result:

result_summary = fi.metrics()

Return:

• results(list): The Evaluation results of each parameter.

• result_summary(list): Summary results are counted according to the fi_mode.

Viewing the Result

for result in results:
    print(result)
for result in result_summary:
    print(result)

The result is as follows:

{'original_acc': 0.9797676282051282}
{'type': 'bitflips_designated', 'mode': 'single_layer', 'size': 1, 'acc': 0.7028245192307693, 'SDC': 0.2769431089743589}
{'type': 'bitflips_designated', 'mode': 'single_layer', 'size': 2, 'acc': 0.5052083333333334, 'SDC': 0.4745592948717948}
{'type': 'bitflips_designated', 'mode': 'all_layer', 'size': 1, 'acc': 0.2077323717948718, 'SDC': 0.7720352564102564}
{'type': 'bitflips_designated', 'mode': 'all_layer', 'size': 2, 'acc': 0.15745192307692307, 'SDC': 0.8223157051282051}
{'type': 'precision_loss', 'mode': 'single_layer', 'size': 1, 'acc': 0.9795673076923077, 'SDC': 0.00020032051282048435}
{'type': 'precision_loss', 'mode': 'single_layer', 'size': 2, 'acc': 0.9797676282051282, 'SDC': 0.0}
{'type': 'precision_loss', 'mode': 'all_layer', 'size': 1, 'acc': 0.9794671474358975, 'SDC': 0.00030048076923072653}
{'type': 'precision_loss', 'mode': 'all_layer', 'size': 2, 'acc': 0.9795673076923077, 'SDC': 0.00020032051282048435}
single_layer_acc_mean:0.791842 single_layer_acc_max:0.979768 single_layer_acc_min:0.505208
single_layer_SDC_mean:0.187926 single_layer_SDC_max:0.474559 single_layer_SDC_min:0.000000
all_layer_acc_mean:0.581055 all_layer_acc_max:0.979567 all_layer_acc_min:0.157452
all_layer_SDC_mean:0.398713 all_layer_SDC_max:0.822316 all_layer_SDC_min:0.000200

• original_acc: The original accuracy of model.

• SDC(Silent Data Corruption): The difference between the original accuracy and the current fault accuracy.

• single_layer_acc_mean/max/min: The average/maximum/minimum accuracy in single_layer mode.

• single_layer_SDC_mean/max/min: The average/maximum/minimum SDC in single_layer mode.

• all_layer_acc_mean/max/min: The average/maximum/minimum accuracy in all_layer mode.

• all_layer_SDC_mean/max/min: The average/maximum/minimum SDC in all_layer mode.