背景介绍
这篇文章是tensorflow serving java api使用的参考案例，基本上把TFS的核心API的用法都介绍清楚。案例主要分为三部分：
- 动态更新模型：用于在TFS处于runtime时候动态加载模型。
- 获取模型状态：用于获取加载的模型的基本信息。
- 在线模型预测：进行在线预测，分类等操作，着重介绍在线预测。
因为模型的预测需要参考模型内部变量，所以可以先行通过TFS的REST接口获取TF模型的元数据然后才能构建TFS的RPC请求对象。
TFS 使用入门
模型源数据获取
curl http://host:port/v1/models/${MODEL_NAME}[/versions/${MODEL_VERSION}]/metadata说明：
- 参考TFS REST API
- 返回结果参考TF模型结构。
public static void getModelStatus() {
// 1、设置访问的RPC协议的host和port
ManagedChannel channel = ManagedChannelBuilder.forAddress(host, port).usePlaintext().build();
// 2、构建PredictionServiceBlockingStub对象
PredictionServiceGrpc.PredictionServiceBlockingStub predictionServiceBlockingStub =
PredictionServiceGrpc.newBlockingStub(channel);
// 3、设置待获取的模型
Model.ModelSpec modelSpec = Model.ModelSpec.newBuilder()
.setName("wdl_model").build();
// 4、构建获取元数据的请求
GetModelMetadata.GetModelMetadataRequest modelMetadataRequest =
GetModelMetadata.GetModelMetadataRequest.newBuilder()
.setModelSpec(modelSpec)
.addAllMetadataField(Arrays.asList("signature_def"))
.build();
// 5、获取元数据
GetModelMetadata.GetModelMetadataResponse getModelMetadataResponse =
predictionServiceBlockingStub.getModelMetadata(modelMetadataRequest);
channel.shutdownNow();
}说明：
- Model.ModelSpec.newBuilder绑定需要访问的模型的名字。
- GetModelMetadataRequest中addAllMetadataField绑定curl命令返回的metadata当中的
signature_def字段。
动态更新模型
public static void addNewModel() {
// 1、构建动态更新模型1
ModelServerConfigOuterClass.ModelConfig modelConfig1 =
ModelServerConfigOuterClass.ModelConfig.newBuilder()
.setBasePath("/models/new_model")
.setName("new_model")
.setModelType(ModelServerConfigOuterClass.ModelType.TENSORFLOW)
.build();
// 2、构建动态更新模型2
ModelServerConfigOuterClass.ModelConfig modelConfig2 =
ModelServerConfigOuterClass.ModelConfig.newBuilder()
.setBasePath("/models/wdl_model")
.setName("wdl_model")
.setModelType(ModelServerConfigOuterClass.ModelType.TENSORFLOW)
.build();
// 3、合并动态更新模型到ModelConfigList对象中
ModelServerConfigOuterClass.ModelConfigList modelConfigList =
ModelServerConfigOuterClass.ModelConfigList.newBuilder()
.addConfig(modelConfig1)
.addConfig(modelConfig2)
.build();
// 4、添加到ModelConfigList到ModelServerConfig对象当中
ModelServerConfigOuterClass.ModelServerConfig modelServerConfig =
ModelServerConfigOuterClass.ModelServerConfig.newBuilder()
.setModelConfigList(modelConfigList)
.build();
// 5、构建ReloadConfigRequest并绑定ModelServerConfig对象。
ModelManagement.ReloadConfigRequest reloadConfigRequest =
ModelManagement.ReloadConfigRequest.newBuilder()
.setConfig(modelServerConfig)
.build();
// 6、构建modelServiceBlockingStub访问句柄
ManagedChannel channel = ManagedChannelBuilder.forAddress(host, port).usePlaintext().build();
ModelServiceGrpc.ModelServiceBlockingStub modelServiceBlockingStub =
ModelServiceGrpc.newBlockingStub(channel);
ModelManagement.ReloadConfigResponse reloadConfigResponse =
modelServiceBlockingStub.handleReloadConfigRequest(reloadConfigRequest);
System.out.println(reloadConfigResponse.getStatus().getErrorMessage());
channel.shutdownNow();
}说明：
- 动态更新模型是一个全量的模型加载，在发布A模型后想动态发布B模型需要同时传递模型A和B的信息。
- 再次强调，需要全量更新，全量更新，全量更新！！！
在线模型预测
public static void doPredict() throws Exception {
// 1、构建feature
Map<String, Feature> featureMap = new HashMap<>();
featureMap.put("match_type", feature(""));
featureMap.put("position", feature(0.0f));
featureMap.put("brand_prefer_1d", feature(0.0f));
featureMap.put("brand_prefer_1m", feature(0.0f));
featureMap.put("brand_prefer_1w", feature(0.0f));
featureMap.put("brand_prefer_2w", feature(0.0f));
featureMap.put("browse_norm_score_1d", feature(0.0f));
featureMap.put("browse_norm_score_1w", feature(0.0f));
featureMap.put("browse_norm_score_2w", feature(0.0f));
featureMap.put("buy_norm_score_1d", feature(0.0f));
featureMap.put("buy_norm_score_1w", feature(0.0f));
featureMap.put("buy_norm_score_2w", feature(0.0f));
featureMap.put("cate1_prefer_1d", feature(0.0f));
featureMap.put("cate1_prefer_2d", feature(0.0f));
featureMap.put("cate1_prefer_1m", feature(0.0f));
featureMap.put("cate1_prefer_1w", feature(0.0f));
featureMap.put("cate1_prefer_2w", feature(0.0f));
featureMap.put("cate2_prefer_1d", feature(0.0f));
featureMap.put("cate2_prefer_1m", feature(0.0f));
featureMap.put("cate2_prefer_1w", feature(0.0f));
featureMap.put("cate2_prefer_2w", feature(0.0f));
featureMap.put("cid_prefer_1d", feature(0.0f));
featureMap.put("cid_prefer_1m", feature(0.0f));
featureMap.put("cid_prefer_1w", feature(0.0f));
featureMap.put("cid_prefer_2w", feature(0.0f));
featureMap.put("user_buy_rate_1d", feature(0.0f));
featureMap.put("user_buy_rate_2w", feature(0.0f));
featureMap.put("user_click_rate_1d", feature(0.0f));
featureMap.put("user_click_rate_1w", feature(0.0f));
Features features = Features.newBuilder().putAllFeature(featureMap).build();
Example example = Example.newBuilder().setFeatures(features).build();
// 2、构建Predict请求
Predict.PredictRequest.Builder predictRequestBuilder = Predict.PredictRequest.newBuilder();
// 3、构建模型请求维度ModelSpec，绑定模型名和预测的签名
Model.ModelSpec.Builder modelSpecBuilder = Model.ModelSpec.newBuilder();
modelSpecBuilder.setName("wdl_model");
modelSpecBuilder.setSignatureName("predict");
predictRequestBuilder.setModelSpec(modelSpecBuilder);
// 4、构建预测请求的维度信息DIM对象
TensorShapeProto.Dim dim = TensorShapeProto.Dim.newBuilder().setSize(300).build();
TensorShapeProto shapeProto = TensorShapeProto.newBuilder().addDim(dim).build();
TensorProto.Builder tensor = TensorProto.newBuilder();
tensor.setTensorShape(shapeProto);
tensor.setDtype(DataType.DT_STRING);
// 5、批量绑定预测请求的数据
for (int i=0; i<300; i++) {
tensor.addStringVal(example.toByteString());
}
predictRequestBuilder.putInputs("examples", tensor.build());
// 6、构建PredictionServiceBlockingStub对象准备预测
ManagedChannel channel = ManagedChannelBuilder.forAddress(host, port).usePlaintext().build();
PredictionServiceGrpc.PredictionServiceBlockingStub predictionServiceBlockingStub =
PredictionServiceGrpc.newBlockingStub(channel);
// 7、执行预测
Predict.PredictResponse predictResponse =
predictionServiceBlockingStub.predict(predictRequestBuilder.build());
// 8、解析请求结果
List<Float> floatList = predictResponse
.getOutputsOrThrow("probabilities")
.getFloatValList();
}说明：
- TFS的RPC请求过程中设置的参数需要考虑TF模型的数据结构。
- TFS的RPC请求有同步和异步两种方式，上述只展示同步方式。
TF模型结构
{
"model_spec": {
"name": "wdl_model",
"signature_name": "",
"version": "4"
},
"metadata": {
"signature_def": {
"signature_def": {
"predict": {
"inputs": {
"examples": {
"dtype": "DT_STRING",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
}],
"unknown_rank": false
},
"name": "input_example_tensor:0"
}
},
"outputs": {
"logistic": {
"dtype": "DT_FLOAT",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
},
{
"size": "1",
"name": ""
}
],
"unknown_rank": false
},
"name": "head/predictions/logistic:0"
},
"class_ids": {
"dtype": "DT_INT64",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
},
{
"size": "1",
"name": ""
}
],
"unknown_rank": false
},
"name": "head/predictions/ExpandDims:0"
},
"probabilities": {
"dtype": "DT_FLOAT",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
},
{
"size": "2",
"name": ""
}
],
"unknown_rank": false
},
"name": "head/predictions/probabilities:0"
},
"classes": {
"dtype": "DT_STRING",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
},
{
"size": "1",
"name": ""
}
],
"unknown_rank": false
},
"name": "head/predictions/str_classes:0"
},
"logits": {
"dtype": "DT_FLOAT",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
},
{
"size": "1",
"name": ""
}
],
"unknown_rank": false
},
"name": "add:0"
}
},
"method_name": "tensorflow/serving/predict"
},
"classification": {
"inputs": {
"inputs": {
"dtype": "DT_STRING",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
}],
"unknown_rank": false
},
"name": "input_example_tensor:0"
}
},
"outputs": {
"classes": {
"dtype": "DT_STRING",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
},
{
"size": "2",
"name": ""
}
],
"unknown_rank": false
},
"name": "head/Tile:0"
},
"scores": {
"dtype": "DT_FLOAT",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
},
{
"size": "2",
"name": ""
}
],
"unknown_rank": false
},
"name": "head/predictions/probabilities:0"
}
},
"method_name": "tensorflow/serving/classify"
},
"regression": {
"inputs": {
"inputs": {
"dtype": "DT_STRING",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
}],
"unknown_rank": false
},
"name": "input_example_tensor:0"
}
},
"outputs": {
"outputs": {
"dtype": "DT_FLOAT",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
},
{
"size": "1",
"name": ""
}
],
"unknown_rank": false
},
"name": "head/predictions/logistic:0"
}
},
"method_name": "tensorflow/serving/regress"
},
"serving_default": {
"inputs": {
"inputs": {
"dtype": "DT_STRING",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
}],
"unknown_rank": false
},
"name": "input_example_tensor:0"
}
},
"outputs": {
"classes": {
"dtype": "DT_STRING",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
},
{
"size": "2",
"name": ""
}
],
"unknown_rank": false
},
"name": "head/Tile:0"
},
"scores": {
"dtype": "DT_FLOAT",
"tensor_shape": {
"dim": [{
"size": "-1",
"name": ""
},
{
"size": "2",
"name": ""
}
],
"unknown_rank": false
},
"name": "head/predictions/probabilities:0"
}
},
"method_name": "tensorflow/serving/classify"
}
}
}
}
}