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Using Kogito to add prediction capabilities to an application

This guide demonstrates how your Quarkus application can use Kogito to add business automation to power it up with predictions.

Kogito is a next generation business automation toolkit that originates from the well known Open Source project Drools (for predictions). Kogito aims at providing another approach to business automation where the main message is to expose your business knowledge (processes, rules, decisions, predictions) in a domain specific way.

Prerequisites

要完成这个指南,你需要:

  • 大概15分钟

  • 编辑器

  • 安装JDK 11以上版本并正确配置了 JAVA_HOME

  • Apache Maven 3.8.1+

  • A working container runtime (Docker or Podman)

  • 如果你愿意的话,还可以选择使用Quarkus CLI

  • 如果你想构建原生可执行程序,可以选择安装Mandrel或者GraalVM,并正确配置(或者使用Docker在容器中进行构建)

Architecture

In this example, we build a very simple microservice which offers one REST endpoint:

  • /LogisticRegressionIrisData

This endpoint will be automatically generated based on given PMML file, that in turn will make use of generated code to make certain predictions based on the data being processed.

PMML file

The PMML file describes the prediction logic of our microservice. It should provide the actual model (Regression, Tree, Scorecard, Clustering, etc.) needed to make the prediction.

Prediction endpoints

Those are the entry points to the service that can be consumed by clients.

Solution

We recommend that you follow the instructions in the next sections and create the application step by step. However, you can go right to the complete example.

Clone the Git repository: git clone https://github.com/quarkusio/quarkus-quickstarts.git, or download an archive.

The solution is located in the kogito-pmml-quickstart directory.

Creating the Maven Project

First, we need a new project. Create a new project with the following command:

CLI
quarkus create app org.acme:kogito-pmml-quickstart \
    --extension=kogito,resteasy-reactive-jackson \
    --no-code
cd kogito-pmml-quickstart

创建Grade项目,请添加 --gradle 或者 --gradle-kotlin-dsl 参数。

关于如何安装并使用Quarkus CLI的更多信息,请参考Quarkus CLI指南

Maven
mvn io.quarkus.platform:quarkus-maven-plugin:2.11.2.Final:create \
    -DprojectGroupId=org.acme \
    -DprojectArtifactId=kogito-pmml-quickstart \
    -Dextensions="kogito,resteasy-reactive-jackson" \
    -DnoCode
cd kogito-pmml-quickstart

创建Grade项目,请添加 -DbuildTool=gradle 或者 -DbuildTool=gradle-kotlin-dsl 参数。

This command generates a Maven project, importing the kogito extension that comes with all needed dependencies and configuration to equip your application with business automation. It also imports the resteasy-reactive-jackson extension that is needed for Kogito to expose REST services.

If you already have your Quarkus project configured, you can add the kogito extension to your project by running the following command in your project base directory:

CLI
quarkus extension add 'kogito'
Maven
./mvnw quarkus:add-extension -Dextensions="kogito"
Gradle
./gradlew addExtension --extensions="kogito"

This will add the following to your build file:

pom.xml
<dependency>
    <groupId>org.kie.kogito</groupId>
    <artifactId>kogito-quarkus</artifactId>
</dependency>
build.gradle
implementation("org.kie.kogito:kogito-quarkus")

Writing the application

Predictions are evaluated based on a PMML model, whose standard and specifications may be read here. Let’s start by adding a simple PMML file: LogisticRegressionIrisData.pmml. It contains a Regression model named LogisticRegressionIrisData, and it uses a regression function to predict plant species from sepal and petal dimensions:

<PMML xmlns="http://www.dmg.org/PMML-4_2" version="4.2">
  <Header/>
  <DataDictionary numberOfFields="5">
    <DataField name="Sepal.Length" optype="continuous" dataType="double"/>
    <DataField name="Sepal.Width" optype="continuous" dataType="double"/>
    <DataField name="Petal.Length" optype="continuous" dataType="double"/>
    <DataField name="Petal.Width" optype="continuous" dataType="double"/>
    <DataField name="Species" optype="categorical" dataType="string">
      <Value value="setosa"/>
      <Value value="virginica"/>
      <Value value="versicolor"/>
    </DataField>
  </DataDictionary>
  <RegressionModel functionName="classification" modelName="LogisticRegressionIrisData" targetFieldName="Species">
    <MiningSchema>
      <MiningField name="Sepal.Length"/>
      <MiningField name="Sepal.Width"/>
      <MiningField name="Petal.Length"/>
      <MiningField name="Petal.Width"/>
      <MiningField name="Species" usageType="target"/>
    </MiningSchema>
    <Output>
      <OutputField name="Probability_setosa" optype="continuous" dataType="double" feature="probability" value="setosa"/>
      <OutputField name="Probability_versicolor" optype="continuous" dataType="double" feature="probability" value="versicolor"/>
      <OutputField name="Probability_virginica" optype="continuous" dataType="double" feature="probability" value="virginica"/>
    </Output>
    <RegressionTable targetCategory="setosa" intercept="0.11822288946815">
      <NumericPredictor name="Sepal.Length" exponent="1" coefficient="0.0660297693761902"/>
      <NumericPredictor name="Sepal.Width" exponent="1" coefficient="0.242847872054487"/>
      <NumericPredictor name="Petal.Length" exponent="1" coefficient="-0.224657116235727"/>
      <NumericPredictor name="Petal.Width" exponent="1" coefficient="-0.0574727291860025"/>
    </RegressionTable>
    <RegressionTable targetCategory="versicolor" intercept="1.57705897385745">
      <NumericPredictor name="Sepal.Length" exponent="1" coefficient="-0.0201536848255179"/>
      <NumericPredictor name="Sepal.Width" exponent="1" coefficient="-0.44561625761404"/>
      <NumericPredictor name="Petal.Length" exponent="1" coefficient="0.22066920522933"/>
      <NumericPredictor name="Petal.Width" exponent="1" coefficient="-0.494306595747785"/>
    </RegressionTable>
    <RegressionTable targetCategory="virginica" intercept="-0.695281863325603">
      <NumericPredictor name="Sepal.Length" exponent="1" coefficient="-0.0458760845506725"/>
      <NumericPredictor name="Sepal.Width" exponent="1" coefficient="0.202768385559553"/>
      <NumericPredictor name="Petal.Length" exponent="1" coefficient="0.00398791100639665"/>
      <NumericPredictor name="Petal.Width" exponent="1" coefficient="0.551779324933787"/>
    </RegressionTable>
  </RegressionModel>
</PMML>

During project compilation, Kogito will read the file and generate the classes needed for the evaluation, together with a couple of REST endpoints.

To get started quickly copy the PMML file from the quickstart.

Running and Using the Application

Running in Dev Mode

To run the microservice in dev mode, use:

CLI
quarkus dev
Maven
./mvnw quarkus:dev
Gradle
./gradlew --console=plain quarkusDev

Running in JVM Mode

When you’re done playing with dev mode you can run it as a standard Java application.

First compile it:

CLI
quarkus build
Maven
./mvnw clean package
Gradle
./gradlew build

Then run it:

java -jar target/quarkus-app/quarkus-run.jar

Running in Native Mode

这个同样的演示可以被编译成本地代码:不需要任何修改。

这意味着您不再需要在您的生产环境中安装JVM,因为运行时技术包含在生产的二进制文件中,并以最小的资源开销优化运行。

Compilation will take a bit longer, so this step is disabled by default; let’s build a native executable with the following command:

CLI
quarkus build --native
Maven
./mvnw package -Dnative
Gradle
./gradlew build -Dquarkus.package.type=native

一杯咖啡的时间后,您就可以直接运行该二进制文件了:

./target/kogito-pmml-quickstart-1.0.0-SNAPSHOT-runner

测试应用程序

To test your application, just send a request to the service with giving the person as JSON payload.

curl -X POST http://localhost:8080/LogisticRegressionIrisData \
    -H 'content-type: application/json' \
    -H 'accept: application/json' \
    -d '{ "Sepal.Length": 6.9, "Sepal.Width": 3.1, "Petal.Length": 5.1, "Petal.Width": 2.3 }'

In the response, you should see the prediction, that should be virginica:

{
  "Species": "virginica"
}

You can also invoke the descriptive endpoint, that will provide also the OutputField evaluated:

curl -X POST http://localhost:8080/LogisticRegressionIrisData/descriptive \
    -H 'content-type: application/json' \
    -H 'accept: application/json' \
    -d '{ "Sepal.Length": 6.9, "Sepal.Width": 3.1, "Petal.Length": 5.1, "Petal.Width": 2.3 }'
{
    "correlationId": null,
    "segmentationId": null,
    "segmentId": null,
    "segmentIndex": 0,
    "resultCode": "OK",
    "resultObjectName": "Species",
    "resultVariables": {
        "Probability_setosa": 0.04871813160275851,
        "Probability_versicolor": 0.04509592640753013,
        "Probability_virginica": 0.9061859419897114,
        "Species": "virginica"
    }
}