flink-ml-core/src/test/java/org/apache/flink/ml/api/PipelineTest.java

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 * Licensed to the Apache Software Foundation (ASF) under one
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 * distributed with this work for additional information
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 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.flink.ml.api;

import org.apache.flink.api.common.restartstrategy.RestartStrategies;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.ml.api.ExampleStages.SumEstimator;
import org.apache.flink.ml.api.ExampleStages.SumModel;
import org.apache.flink.ml.builder.Pipeline;
import org.apache.flink.ml.builder.PipelineModel;
import org.apache.flink.streaming.api.environment.ExecutionCheckpointingOptions;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;
import org.apache.flink.test.util.AbstractTestBase;

import org.junit.Before;
import org.junit.Test;

import java.nio.file.Files;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

/** Tests the behavior of Pipeline and PipelineModel. */
public class PipelineTest extends AbstractTestBase {
    private StreamExecutionEnvironment env;
    private StreamTableEnvironment tEnv;

    @Before
    public void before() {
        Configuration config = new Configuration();
        config.set(ExecutionCheckpointingOptions.ENABLE_CHECKPOINTS_AFTER_TASKS_FINISH, true);
        env = StreamExecutionEnvironment.getExecutionEnvironment(config);
        env.setParallelism(4);
        env.enableCheckpointing(100);
        env.setRestartStrategy(RestartStrategies.noRestart());
        tEnv = StreamTableEnvironment.create(env);
    }

    @Test
    public void testPipelineModel() throws Exception {
        // Builds a PipelineModel that increments input value by 60. This PipelineModel consists of
        // three stages where each stage increments input value by 10, 20, and 30 respectively.
        SumModel modelA = new SumModel().setModelData(tEnv.fromValues(10));
        SumModel modelB = new SumModel().setModelData(tEnv.fromValues(20));
        SumModel modelC = new SumModel().setModelData(tEnv.fromValues(30));

        List<Stage<?>> stages = Arrays.asList(modelA, modelB, modelC);
        Model<?> model = new PipelineModel(stages);
        List<List<Integer>> inputs = Collections.singletonList(Arrays.asList(1, 2, 3));
        List<Integer> output = Arrays.asList(61, 62, 63);

        // Executes the original PipelineModel and verifies that it produces the expected output.
        TestUtils.executeAndCheckOutput(env, model, inputs, output, null, null);

        // Saves and loads the PipelineModel.
        String path = Files.createTempDirectory("").toString();
        model.save(path);
        env.execute();

        Model<?> loadedModel = PipelineModel.load(tEnv, path);
        // Executes the loaded PipelineModel and verifies that it produces the expected output.
        TestUtils.executeAndCheckOutput(env, loadedModel, inputs, output, null, null);
    }

    @Test
    public void testPipeline() throws Exception {
        // Builds a Pipeline that consists of a Model, an Estimator, and a model.
        SumModel modelA = new SumModel().setModelData(tEnv.fromValues(10));
        SumModel modelB = new SumModel().setModelData(tEnv.fromValues(30));

        List<Stage<?>> stages = Arrays.asList(modelA, new SumEstimator(), modelB);
        Estimator<?, ?> estimator = new Pipeline(stages);
        List<List<Integer>> inputs = Collections.singletonList(Arrays.asList(1, 2, 3));
        List<Integer> output = Arrays.asList(77, 78, 79);

        // Executes the original Pipeline and verifies that it produces the expected output.
        TestUtils.executeAndCheckOutput(env, estimator, inputs, output, null, null);

        // Saves and loads the Pipeline.
        String path = Files.createTempDirectory("").toString();
        estimator.save(path);
        env.execute();

        Estimator<?, ?> loadedEstimator = Pipeline.load(tEnv, path);
        // Executes the loaded Pipeline and verifies that it produces the expected output.
        TestUtils.executeAndCheckOutput(env, loadedEstimator, inputs, output, null, null);
    }
}