Windows 下运行 Hadoop 并部署到 AWS（qbit）

本文环境

Windows 10
JDK 8
IntelliJ IDEA 2019.3.4(Community Edition)
Hadoop 2.8.5
AWS EMR 5.3.0

单机程序

• 新建 Maven 工程

• 修改 pom.xml 配置

<?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>mapreducedemo</groupId>
    <artifactId>mapreducedemo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <hadoop.version>2.8.5</hadoop.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-client</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
    </dependencies>
</project>

• 新建 Package 和 Java Class

• 从官方拷贝代码到 WordCount.java

package mapreducedemo;

import java.io.IOException;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

public class WordCount {

    public static class TokenizerMapper
            extends Mapper<Object, Text, Text, IntWritable>{

        private final static IntWritable one = new IntWritable(1);
        private Text word = new Text();

        public void map(Object key, Text value, Context context
        ) throws IOException, InterruptedException {
            StringTokenizer itr = new StringTokenizer(value.toString());
            while (itr.hasMoreTokens()) {
                word.set(itr.nextToken());
                context.write(word, one);
            }
        }
    }

    public static class IntSumReducer
            extends Reducer<Text,IntWritable,Text,IntWritable> {
        private IntWritable result = new IntWritable();

        public void reduce(Text key, Iterable<IntWritable> values,
                           Context context
        ) throws IOException, InterruptedException {
            int sum = 0;
            for (IntWritable val : values) {
                sum += val.get();
            }
            result.set(sum);
            context.write(key, result);
        }
    }

    public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
        Job job = Job.getInstance(conf, "word count");
        job.setJarByClass(WordCount.class);
        job.setMapperClass(TokenizerMapper.class);
        job.setCombinerClass(IntSumReducer.class);
        job.setReducerClass(IntSumReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}

• 将文本文件 demo.txt 放到 pom.xml 同级目录
• 添加运行配置

• 点击运行，报如下错误

Exception in thread "main" java.lang.UnsatisfiedLinkError: org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)Z

• 到官网下载并解压 hadoop-2.8.5.tar.gz

• 下载 winutils/hadoop-2.8.5/，将 bin 目录里面的文件拷贝到 hadoop-2.8.5/bin （复制或替换）
• 设置环境变量（qbit 为了不跟系统环境变量冲突，直接在 IDEA 里面设置）

• 重新运行，正常输入结果。

部署到 AWS

• 在 pom.xml 里面添加 build 标签及内容，完整 pom.xml 如下

<?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>mapreducedemo</groupId>
    <artifactId>mapreducedemo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <java.version>1.8</java.version>
        <hadoop.version>2.8.5</hadoop.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-client</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.2.4</version>
                <configuration>
                    <createDependencyReducedPom>false</createDependencyReducedPom>
                </configuration>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <filters>
                                <filter>
                                    <artifact>*:*</artifact>
                                    <excludes>
                                        <exclude>META-INF/*.SF</exclude>
                                        <exclude>META-INF/*.DSA</exclude>
                                        <exclude>META-INF/*.RSA</exclude>
                                    </excludes>
                                </filter>
                            </filters>
                            <transformers>
                                <transformer
                                        implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
                                <transformer
                                        implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass>mapreducedemo.WordCount</mainClass>
                                </transformer>
                            </transformers>
                            <artifactSet>
                                <excludes>
                                    <exclude>junit:junit</exclude>
                                </excludes>
                            </artifactSet>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

• 添加运行配置

• 运行并导出 jar
• 将 demo.txt 拷贝到 target 目录

• cmd 命令行测试是否正常

...\mapreducedemo\target>set HADOOP_HOME=E:\hadoop\hadoop-2.8.5

...\mapreducedemo\target>set PATH=E:\hadoop\hadoop-2.8.5\bin;%PATH%

...\mapreducedemo\target>java -jar mapreducedemo-1.0-SNAPSHOT.jar demo.txt output
log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

• 将文件上传到 S3

s3://zt-hadoop-cn-northwest-1/jar/mapreducedemo-1.0-SNAPSHOT.jar
s3://zt-hadoop-cn-northwest-1/usr/qbit/input/idea.txt

• 创建 EMR 集群（默认配置）

• 添加步骤（输出目录应不存在）

• 等待程序运行

• 在 S3 查看运行结果 s3://zt-hadoop-cn-northwest-1/usr/qbit/output

本文出自 qbit snap