/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file 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
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.spark.examples;
import org.apache.spark.SparkConf;
import org.apache.spark.SparkJobInfo;
import org.apache.spark.SparkStageInfo;
import org.apache.spark.api.java.JavaFutureAction;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.Function;
import java.util.Arrays;
import java.util.List;
/**
* Example of using Spark's status APIs from Java.
*/
public final class JavaStatusAPIDemo {
public static final String APP_NAME = "JavaStatusAPIDemo";
public static final class IdentityWithDelay<T> implements Function<T, T> {
@Override
public T call(T x) throws Exception {
Thread.sleep(2 * 1000); // 2 seconds
return x;
}
}
public static void main(String[] args) throws Exception {
SparkConf sparkConf = new SparkConf().setAppName(APP_NAME);
final JavaSparkContext sc = new JavaSparkContext(sparkConf);
// Example of implementing a progress reporter for a simple job.
JavaRDD<Integer> rdd = sc.parallelize(Arrays.asList(1, 2, 3, 4, 5), 5).map(
new IdentityWithDelay<Integer>());
JavaFutureAction<List<Integer>> jobFuture = rdd.collectAsync();
while (!jobFuture.isDone()) {
Thread.sleep(1000); // 1 second
List<Integer> jobIds = jobFuture.jobIds();
if (jobIds.isEmpty()) {
continue;
}
int currentJobId = jobIds.get(jobIds.size() - 1);
SparkJobInfo jobInfo = sc.getJobInfo(currentJobId);
SparkStageInfo stageInfo = sc.getStageInfo(jobInfo.stageIds()[0]);
System.out.println(stageInfo.numTasks() + " tasks total: " + stageInfo.numActiveTasks() +
" active, " + stageInfo.numCompletedTasks() + " complete");
}
System.out.println("Job results are: " + jobFuture.get());
sc.stop();
}
}