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