先决条件 - Amazon SageMaker

本文属于机器翻译版本。若本译文内容与英语原文存在差异,则一律以英文原文为准。

先决条件

注意

如果您使用 AWS SDK for Python (Boto3)、或 SageMaker 控制台编译模型 AWS CLI,请按照本节中的说明进行操作。

要创建 SageMaker NEO 编译模型,您需要以下内容:

  1. 一张 Docker 镜像 Amazon ECR URI。您可以从此列表中选择一个满足您需求的产品。

  2. 入口点脚本文件:

    1. 适用于 PyTorch 和MXNet型号:

      如果您使用训练模型 SageMaker,则训练脚本必须实现下述函数。训练脚本在推理过程中用作入口点脚本。在使用 M MXNetodule 和 SageMaker Neo 进行MNIST训练、编译和部署中详述的示例中,训练脚本 (mnist.py) 实现了所需的函数。

      如果您没有使用训练模型 SageMaker,则需要提供可在推理时使用的入口点脚本 (inference.py) 文件。基于框架 PyTorch —— MXNet 或——推理脚本的位置必须符合的 SageMaker Python SDK 模型目录结构 MxNet模型目录结构。 PyTorch

      使用 Neo Inference 优化的容器镜像CPU和开GPU启以及实例类型时,推理脚本必须实现以下功能:PyTorchMXNet

      • model_fn:加载模型。(可选)

      • input_fn:将传入的请求负载转换为 numpy 数组。

      • predict_fn:执行预测。

      • output_fn:将预测输出转换为响应负载。

      • 或者,您可以将 transform_fn 定义为组合 input_fnpredict_fnoutput_fn

      以下是名为 code (code/inference.py) PyTorch 和MXNet(Gluon and Mod ule)的目录中的inference.py脚本示例。这些示例首先加载模型,然后将其提供给以下图像数据GPU:

      MXNet Module
      import numpy as np import json import mxnet as mx import neomx # noqa: F401 from collections import namedtuple Batch = namedtuple('Batch', ['data']) # Change the context to mx.cpu() if deploying to a CPU endpoint ctx = mx.gpu() def model_fn(model_dir): # The compiled model artifacts are saved with the prefix 'compiled' sym, arg_params, aux_params = mx.model.load_checkpoint('compiled', 0) mod = mx.mod.Module(symbol=sym, context=ctx, label_names=None) exe = mod.bind(for_training=False, data_shapes=[('data', (1,3,224,224))], label_shapes=mod._label_shapes) mod.set_params(arg_params, aux_params, allow_missing=True) # Run warm-up inference on empty data during model load (required for GPU) data = mx.nd.empty((1,3,224,224), ctx=ctx) mod.forward(Batch([data])) return mod def transform_fn(mod, image, input_content_type, output_content_type): # pre-processing decoded = mx.image.imdecode(image) resized = mx.image.resize_short(decoded, 224) cropped, crop_info = mx.image.center_crop(resized, (224, 224)) normalized = mx.image.color_normalize(cropped.astype(np.float32) / 255, mean=mx.nd.array([0.485, 0.456, 0.406]), std=mx.nd.array([0.229, 0.224, 0.225])) transposed = normalized.transpose((2, 0, 1)) batchified = transposed.expand_dims(axis=0) casted = batchified.astype(dtype='float32') processed_input = casted.as_in_context(ctx) # prediction/inference mod.forward(Batch([processed_input])) # post-processing prob = mod.get_outputs()[0].asnumpy().tolist() prob_json = json.dumps(prob) return prob_json, output_content_type
      MXNet Gluon
      import numpy as np import json import mxnet as mx import neomx # noqa: F401 # Change the context to mx.cpu() if deploying to a CPU endpoint ctx = mx.gpu() def model_fn(model_dir): # The compiled model artifacts are saved with the prefix 'compiled' block = mx.gluon.nn.SymbolBlock.imports('compiled-symbol.json',['data'],'compiled-0000.params', ctx=ctx) # Hybridize the model & pass required options for Neo: static_alloc=True & static_shape=True block.hybridize(static_alloc=True, static_shape=True) # Run warm-up inference on empty data during model load (required for GPU) data = mx.nd.empty((1,3,224,224), ctx=ctx) warm_up = block(data) return block def input_fn(image, input_content_type): # pre-processing decoded = mx.image.imdecode(image) resized = mx.image.resize_short(decoded, 224) cropped, crop_info = mx.image.center_crop(resized, (224, 224)) normalized = mx.image.color_normalize(cropped.astype(np.float32) / 255, mean=mx.nd.array([0.485, 0.456, 0.406]), std=mx.nd.array([0.229, 0.224, 0.225])) transposed = normalized.transpose((2, 0, 1)) batchified = transposed.expand_dims(axis=0) casted = batchified.astype(dtype='float32') processed_input = casted.as_in_context(ctx) return processed_input def predict_fn(processed_input_data, block): # prediction/inference prediction = block(processed_input_data) return prediction def output_fn(prediction, output_content_type): # post-processing prob = prediction.asnumpy().tolist() prob_json = json.dumps(prob) return prob_json, output_content_type
      PyTorch 1.4 and Older
      import os import torch import torch.nn.parallel import torch.optim import torch.utils.data import torch.utils.data.distributed import torchvision.transforms as transforms from PIL import Image import io import json import pickle def model_fn(model_dir): """Load the model and return it. Providing this function is optional. There is a default model_fn available which will load the model compiled using SageMaker Neo. You can override it here. Keyword arguments: model_dir -- the directory path where the model artifacts are present """ # The compiled model is saved as "compiled.pt" model_path = os.path.join(model_dir, 'compiled.pt') with torch.neo.config(model_dir=model_dir, neo_runtime=True): model = torch.jit.load(model_path) device = torch.device("cuda" if torch.cuda.is_available() else "cpu") model = model.to(device) # We recommend that you run warm-up inference during model load sample_input_path = os.path.join(model_dir, 'sample_input.pkl') with open(sample_input_path, 'rb') as input_file: model_input = pickle.load(input_file) if torch.is_tensor(model_input): model_input = model_input.to(device) model(model_input) elif isinstance(model_input, tuple): model_input = (inp.to(device) for inp in model_input if torch.is_tensor(inp)) model(*model_input) else: print("Only supports a torch tensor or a tuple of torch tensors") return model def transform_fn(model, request_body, request_content_type, response_content_type): """Run prediction and return the output. The function 1. Pre-processes the input request 2. Runs prediction 3. Post-processes the prediction output. """ # preprocess decoded = Image.open(io.BytesIO(request_body)) preprocess = transforms.Compose([ transforms.Resize(256), transforms.CenterCrop(224), transforms.ToTensor(), transforms.Normalize( mean=[ 0.485, 0.456, 0.406], std=[ 0.229, 0.224, 0.225]), ]) normalized = preprocess(decoded) batchified = normalized.unsqueeze(0) # predict device = torch.device("cuda" if torch.cuda.is_available() else "cpu") batchified = batchified.to(device) output = model.forward(batchified) return json.dumps(output.cpu().numpy().tolist()), response_content_type
      PyTorch 1.5 and Newer
      import os import torch import torch.nn.parallel import torch.optim import torch.utils.data import torch.utils.data.distributed import torchvision.transforms as transforms from PIL import Image import io import json import pickle def model_fn(model_dir): """Load the model and return it. Providing this function is optional. There is a default_model_fn available, which will load the model compiled using SageMaker Neo. You can override the default here. The model_fn only needs to be defined if your model needs extra steps to load, and can otherwise be left undefined. Keyword arguments: model_dir -- the directory path where the model artifacts are present """ # The compiled model is saved as "model.pt" model_path = os.path.join(model_dir, 'model.pt') device = torch.device("cuda" if torch.cuda.is_available() else "cpu") model = torch.jit.load(model_path, map_location=device) model = model.to(device) return model def transform_fn(model, request_body, request_content_type, response_content_type): """Run prediction and return the output. The function 1. Pre-processes the input request 2. Runs prediction 3. Post-processes the prediction output. """ # preprocess decoded = Image.open(io.BytesIO(request_body)) preprocess = transforms.Compose([ transforms.Resize(256), transforms.CenterCrop(224), transforms.ToTensor(), transforms.Normalize( mean=[ 0.485, 0.456, 0.406], std=[ 0.229, 0.224, 0.225]), ]) normalized = preprocess(decoded) batchified = normalized.unsqueeze(0) # predict device = torch.device("cuda" if torch.cuda.is_available() else "cpu") batchified = batchified.to(device) output = model.forward(batchified) return json.dumps(output.cpu().numpy().tolist()), response_content_type
    2. 对于 inf1 实例或 onnx、xgboost、keras 容器映像

      对于所有其他 Neo Inference 优化的容器映像或 inferentia 实例类型,入口点脚本必须为 Neo 深度学习运行时系统实施以下功能:

      • neo_preprocess:将传入的请求负载转换为 numpy 数组。

      • neo_postprocess:将 Neo 深度学习运行时系统的预测输出转换为响应正文。

        注意

        前两个函数不使用MXNet PyTorch、或 TensorFlow的任何功能。

      有关如何使用这些功能的示例,请参阅 Neo 模型编译示例笔记本

    3. 对于 TensorFlow 模特

      如果您的模型在将数据发送到模型之前需要自定义的预处理和后处理逻辑,则必须指定推理时可以使用的入口点脚本 inference.py 文件。该脚本应实施一对 input_handleroutput_handler 功能或单个处理程序功能。

      注意

      请注意,如果处理程序功能已实施,则 input_handleroutput_handler 被忽略。

      以下是 inference.py 脚本的代码示例,您可以将该脚本与编译模型组合在一起,对图像分类模型执行自定义的预处理和后处理。 SageMaker 客户端将图像文件作为application/x-image内容类型发送给input_handler函数,然后将其转换为该函数JSON。然后,使用将转换后的图像文件发送到 Tensorflow 模型服务器 (TFX)。REST API

      import json import numpy as np import json import io from PIL import Image def input_handler(data, context): """ Pre-process request input before it is sent to TensorFlow Serving REST API Args: data (obj): the request data, in format of dict or string context (Context): an object containing request and configuration details Returns: (dict): a JSON-serializable dict that contains request body and headers """ f = data.read() f = io.BytesIO(f) image = Image.open(f).convert('RGB') batch_size = 1 image = np.asarray(image.resize((512, 512))) image = np.concatenate([image[np.newaxis, :, :]] * batch_size) body = json.dumps({"signature_name": "serving_default", "instances": image.tolist()}) return body def output_handler(data, context): """Post-process TensorFlow Serving output before it is returned to the client. Args: data (obj): the TensorFlow serving response context (Context): an object containing request and configuration details Returns: (bytes, string): data to return to client, response content type """ if data.status_code != 200: raise ValueError(data.content.decode('utf-8')) response_content_type = context.accept_header prediction = data.content return prediction, response_content_type

      如果没有自定义的预处理或后处理,则 SageMaker 客户端会以JSON类似的方式将文件图像转换为,然后再将其发送到 SageMaker 端点。

      有关更多信息,请参阅 SageMaker Python 中的部署到 TensorFlow 服务端点SDK

  3. 包含已编译模型工件URI的 Amazon S3 存储桶。