HBase快速入门系列(7) | 官方HBase-MapReduce与自定义

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  此篇为大家带来的是官方HBase-MapReduce与自定义。

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  通过HBase的相关JavaAPI，我们可以实现伴随HBase操作的MapReduce过程，比如使用MapReduce将数据从本地文件系统导入到HBase的表中，比如我们从HBase中读取一些原始数据后使用MapReduce做数据分析。

标注：
此处为反爬虫标记：读者可自行忽略

原文地址：https://buwenbuhuo.blog.csdn.net/

1. 官方HBase-MapReduce

1．查看HBase的MapReduce任务的执行

[bigdata@hadoop002 hbase]$ bin/hbase mapredcp

上图标记处为所需jar包

2. 环境变量的导入

• 1. 执行环境变量的导入（临时生效，在命令行执行下述操作）

$ export HBASE_HOME=/opt/module/hbase
$ export HADOOP_HOME=/opt/module/hadoop-2.7.2
$ export HADOOP_CLASSPATH=`${HBASE_HOME}/bin/hbase mapredcp`

// 也可以直接这样
[bigdata@hadoop002 hbase]$ export HADOOP_CLASSPATH=`/opt/module/hbase/bin/hbase mapredcp`

配置完成后查看是否成功

• 2. 永久生效：在/etc/profile配置

export HBASE_HOME=/opt/module/hbase
export HADOOP_HOME=/opt/module/hadoop-2.7.2

在hadoop-env.sh中配置：（注意：在for循环之后配）

export HADOOP_CLASSPATH=$HADOOP_CLASSPATH:/opt/module/hbase/lib/*

• 3. 运行官方的MapReduce任务

– 案例一：统计Student表中有多少行数据

[bigdata@hadoop002 hbase]$ /opt/module/hadoop-2.7.2/bin/yarn jar lib/hbase-server-1.3.1.jar rowcounter student

– 案例二：使用MapReduce将HDFS导入到HBase

• 1.在本地创建一个tsv格式的文件：fruit.tsv

[bigdata@hadoop002 datas]$ vim fruit.tsv

1001	Apple	Red
1002	Pear	Yellow
1003	Pineapple	Yellow

• 2.创建HBase表

hbase(main):001:0> create 'fruit','info'

• 3.在HDFS中创建input_fruit文件夹并上传fruit.tsv文件

[bigdata@hadoop002 datas]$ hadoop fs -mkdir /input_fruit/
[bigdata@hadoop002 datas]$ hadoop fs -put fruit.tsv /input_fruit/

• 4.执行MapReduce到HBase的fruit表中

[bigdata@hadoop002 hbase]$ /opt/module/hadoop-2.7.2/bin/yarn jar lib/hbase-server-1.3.1.jar importtsv \
-Dimporttsv.columns=HBASE_ROW_KEY,info:name,info:color fruit \
hdfs://hadoop002:9000/input_fruit

• 5.使用scan命令查看导入后的结果

hbase(main):001:0> scan ‘fruit’

经过测试证明是没问题的

2. 自定义HBase-MapReduce1

目标：将fruit表中的一部分数据，通过MR迁入到fruit_mr表中。

• 1.构建ReadMapper类，用于读取fruit表中的数据

package com.buwenbuhuo.hbase.mr;

import java.io.IOException;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableMapper;
import org.apache.hadoop.hbase.util.Bytes;


/**
 * @author 卜温不火
 * @create 2020-05-12 19:32
 * com.buwenbuhuo.hbase.mr - the name of the target package where the new class or interface will be created.
 * hbase0512 - the name of the current project.
 */
public class ReadMapper extends TableMapper<ImmutableBytesWritable,Put> {

    @Override
    protected void map(ImmutableBytesWritable key, Result value, Context context) throws IOException, InterruptedException {
        Put put = new Put(key.copyBytes());

        for (Cell cell : value.rawCells()) {
            if ("name".equals(Bytes.toString(CellUtil.cloneQualifier(cell)))){

                put.add(cell);

            }
        }
        context.write(key,put);
    }
}

• 2. 构建WriteReducer类，用于将读取到的fruit表中的数据写入到fruit_mr表中

package com.buwenbuhuo.hbase.mr;

import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableReducer;
import org.apache.hadoop.io.NullWritable;

import java.io.IOException;


/**
 * @author 卜温不火
 * @create 2020-05-12 19:32
 * com.buwenbuhuo.hbase.mr - the name of the target package where the new class or interface will be created.
 * hbase0512 - the name of the current project.
 */
public class WriteReducer extends TableReducer<ImmutableBytesWritable,Put, NullWritable> {

    @Override
    protected void reduce(ImmutableBytesWritable key, Iterable<Put> values, Context context) throws IOException, InterruptedException {
        for (Put value : values) {
            context.write(NullWritable.get(),value);
        }
    }
}

• 3. 构建Driver用于组装运行Job任务

package com.buwenbuhuo.hbase.mr;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.HRegionPartitioner;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.mapreduce.Job;

import java.io.IOException;

/**
 * @author 卜温不火
 * @create 2020-05-12 19:32
 * com.buwenbuhuo.hbase.mr - the name of the target package where the new class or interface will be created.
 * hbase0512 - the name of the current project.
 */
public class Driver {

    public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {

        Configuration conf = HBaseConfiguration.create();
        conf.set("hbase.zookeeper.quorum", "hadoop002,hadoop003,hadoop004");
        conf.set("hbase.zookeeper.property.clientPort", "2181");

        Job job = Job.getInstance();

        job.setJarByClass(Driver.class);

        Scan scan = new Scan();

        TableMapReduceUtil.initTableMapperJob(
                "fruit",
                scan,
                ReadMapper.class,
                ImmutableBytesWritable.class,
                Put.class,
                job
        );

        job.setNumReduceTasks(100);

        TableMapReduceUtil.initTableReducerJob("fruit_mr",WriteReducer.class,job,HRegionPartitioner.class);

        job.waitForCompletion(true);

    }

}

• 4. 打包并上传
  
  
• 5. 创建表

hbase(main):003:0> create 'fruit_mr','info'

• 6. 运行验证

[bigdata@hadoop002 hbase]$ hadoop jar hbase-0512-1.0-SNAPSHOT.jar com.buwenbuhuo.hbase.mr.Driver

hbase(main):005:0> scan 'fruit_mr'

3. 自定义HBase-MapReduce2

目标：实现将HDFS中的数据写入到HBase表中。

• 1. 构建ReadFruitFromHDFSMapper于读取HDFS中的文件数据

package com.buwenbuhuo.hbase.mr2;

import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;

import java.io.IOException;

/**
 * @author 卜温不火
 * @create 2020-05-12 22:41
 * com.buwenbuhuo.hbase.mr2 - the name of the target package where the new class or interface will be created.
 * hbase0512 - the name of the current project.
 */
public class ReadMapper extends Mapper<LongWritable, Text, ImmutableBytesWritable, Put> {

    @Override
    protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {

        String[] split = value.toString().split("\t");

        if (split.length <= 3){
            return;
        }

        Put put = new Put(Bytes.toBytes(split[0]));

        put.addColumn(Bytes.toBytes("info"),Bytes.toBytes("name"),Bytes.toBytes(split[1]));
        put.addColumn(Bytes.toBytes("info"),Bytes.toBytes("color"),Bytes.toBytes(split[2]));

        context.write(new ImmutableBytesWritable(Bytes.toBytes(split[0])),put);

    }
}

• 2. 构建WriteFruitMRFromTxtReducer类

package com.buwenbuhuo.hbase.mr2;

import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableReducer;
import org.apache.hadoop.io.NullWritable;

import java.io.IOException;

/**
 * @author 卜温不火
 * @create 2020-05-12 23:09
 * com.buwenbuhuo.hbase.mr2 - the name of the target package where the new class or interface will be created.
 * hbase0512 - the name of the current project.
 */
public class WriteReducer extends TableReducer<ImmutableBytesWritable, Put, NullWritable> {
    @Override
    protected void reduce(ImmutableBytesWritable key, Iterable<Put> values, Context context) throws IOException, InterruptedException {

        for (Put value : values){
            context.write(NullWritable.get(),value);
        }

    }
}

• 3.创建Driver

package com.buwenbuhuo.hbase.mr2;

import com.buwenbuhuo.hbase.mr.WriteReducer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.HRegionPartitioner;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;

import java.io.IOException;

/**
 * @author 卜温不火
 * @create 2020-05-12 23:09
 * com.buwenbuhuo.hbase.mr2 - the name of the target package where the new class or interface will be created.
 * hbase0512 - the name of the current project.
 */
public class Driver {

    public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {
        Configuration conf = HBaseConfiguration.create();
        conf.set("hbase.zookeeper.quorum", "hadoop002,hadoop003,hadoop004");
        Job job = Job.getInstance(conf);

        job.setJarByClass(Driver.class);

        job.setMapperClass(ReadMapper.class);

        job.setMapOutputKeyClass(ImmutableBytesWritable.class);
        job.setMapOutputValueClass(Put.class);

        FileInputFormat.setInputPaths(job,new Path("/input_fruit"));

        job.setNumReduceTasks(10);

        TableMapReduceUtil.initTableReducerJob("fruit_mr", WriteReducer.class,job, HRegionPartitioner.class);

        job.waitForCompletion(true);
    }

}

• 4. 打包上传
  
  
• 5.测试运行

[bigdata@hadoop002 hbase]$ hadoop jar hbase-0512-1.0-SNAPSHOT.jar com.buwenbuhuo.hbase.mr2.Driver

  本次的分享就到这里了,

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