Spark机器学习1·编程入门(scala/java/python)

Spark安装目录

/Users/erichan/Garden/spark-1.4.0-bin-hadoop2.6

• 基本测试

./bin/run-example org.apache.spark.examples.SparkPi

MASTER=local[20] ./bin/run-example org.apache.spark.examples.SparkPi

scala

import org.apache.spark.SparkContext
import org.apache.spark.SparkContext._

/**
 * A simple Spark app in Scala
 */
object ScalaApp {

  def main(args: Array[String]) {
    val sc = new SparkContext("local[2]", "First Spark App")
    val data = sc.textFile("data/UserPurchaseHistory.csv")
      .map(line => line.split(","))
      .map(purchaseRecord => (purchaseRecord(0), purchaseRecord(1), purchaseRecord(2)))
    val numPurchases = data.count()
    val uniqueUsers = data.map { case (user, product, price) => user }.distinct().count()
    val totalRevenue = data.map { case (user, product, price) => price.toDouble }.sum()
    val productsByPopularity = data
      .map { case (user, product, price) => (product, 1) }
      .reduceByKey(_ + _)
      .collect()
      .sortBy(-_._2)

    val mostPopular = productsByPopularity(0)
    println("Total purchases: " + numPurchases)
    println("Unique users: " + uniqueUsers)
    println("Total revenue: " + totalRevenue)
    println("Most popular product: %s with %d purchases".format(mostPopular._1, mostPopular._2))
    sc.stop()
  }
}

build.sbt

name := "scala-spark-app"

version := "1.0"

scalaVersion := "2.11.6"

libraryDependencies += "org.apache.spark" %% "spark-core" % "1.4.0"

erichan:scala-spark-app/ $ sbt run

java 8

import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.PairFunction;
import scala.Tuple2;
import java.util.List;
public class JavaApp {
    public static void main(String[] args) {
        JavaSparkContext sc = new JavaSparkContext("local[2]", "First Spark App");
        JavaRDD<String[]> data = sc.textFile("data/UserPurchaseHistory.csv").map(s -> s.split(","));
        long numPurchases = data.count();
        long uniqueUsers = data.map(strings -> strings[0]).distinct().count();
        double totalRevenue = data.mapToDouble(strings -> Double.parseDouble(strings[2])).sum();

        List<Tuple2<String, Integer>> pairs = data.mapToPair(
                new PairFunction<String[], String, Integer>() {
                    @Override
                    public Tuple2<String, Integer> call(String[] strings) throws Exception {
                        return new Tuple2(strings[1], 1);
                    }
                }
        ).reduceByKey((i1, i2) -> i1 + i2).collect();
        pairs.sort((o1, o2) -> -(o1._2() - o2._2()));

        String mostPopular = pairs.get(0)._1();
        int purchases = pairs.get(0)._2();
        System.out.println("Total purchases: " + numPurchases);
        System.out.println("Unique users: " + uniqueUsers);
        System.out.println("Total revenue: " + totalRevenue);
        System.out.println(String.format("Most popular product: %s with %d purchases", mostPopular, purchases));
        sc.stop();
    }
}

Maven pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>java-spark-app</groupId>
    <artifactId>java-spark-app</artifactId>
    <version>1.0</version>

    <dependencies>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-core_2.11</artifactId>
            <version>1.4.0</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

python

from pyspark import SparkContext

sc = SparkContext("local[2]", "First Spark App")
data = sc.textFile("data/UserPurchaseHistory.csv").map(lambda line: line.split(",")).map(lambda record: (record[0], record[1], record[2]))
numPurchases = data.count()
uniqueUsers = data.map(lambda record: record[0]).distinct().count()
totalRevenue = data.map(lambda record: float(record[2])).sum()
products = data.map(lambda record: (record[1], 1.0)).reduceByKey(lambda a, b: a + b).collect()
mostPopular = sorted(products, key=lambda x: x[1], reverse=True)[0]

print "Total purchases: %d" % numPurchases
print "Unique users: %d" % uniqueUsers
print "Total revenue: %2.2f" % totalRevenue
print "Most popular product: %s with %d purchases" % (mostPopular[0], mostPopular[1])

sc.stop()

cd /Users/erichan/Garden/spark-1.4.0-bin-hadoop2.6/bin
./spark-submit pythonapp.py