7、Base批量装载-Bulk load(示例二:写千万级数据-mysql数据以ORCFile写入hdfs,然后导入hbase)
  nNPyvzOmRTFq 2023年11月02日 63 0

Apache Hbase 系列文章

1、hbase-2.1.0介绍及分布式集群部署、HA集群部署、验证、硬件配置推荐 2、hbase-2.1.0 shell基本操作详解 3、HBase的java API基本操作(创建、删除表以及对数据的添加、删除、查询以及多条件查询) 4、HBase使用(namespace、数据分区、rowkey设计、原生api访问hbase) 5、Apache Phoenix(5.0.0-5.1.2) 介绍及部署、使用(基本使用、综合使用、二级索引示例)、数据分区示例 6、Base批量装载——Bulk load(示例一:基本使用示例) 7、Base批量装载-Bulk load(示例二:写千万级数据-mysql数据以ORCFile写入hdfs,然后导入hbase) 8、HBase批量装载-Bulk load(示例三:写千万级数据-mysql数据直接写成Hbase需要的数据,然后导入hbase)


(文章目录)


本文主要介绍Bulk load的用法,即MapReduce和bulk load的配合使用。 本文是介绍Bulk load用法的系列的第二篇。 本文前提依赖hbase可用、phoenix可用、mysql可用、hadoop是HA环境。 本文分为2个部分,即实现步骤和实现。

一、实现步骤

示例二:本示例包含 1、从mysql数据库中导出1260万(12606948)数据到ORC文件,并写入HDFS中 2、从HDFS中读取ORC数据文件,写成Hbase导入数据需要的格式 3、加载数据到Hbase中 4、通过phoenix客户端查询数据 5、hadoop环境是HA

二、实现

1、pom.xml

本pom.xml文件不仅仅是本示例的依赖,还有其他的项目的依赖,没有单独的拆分。

<?xml version="1.0"?>
<project
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
	xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>com.okcard</groupId>
		<artifactId>bigdata-component</artifactId>
		<version>0.0.1-SNAPSHOT</version>
	</parent>
	<groupId>com.okcard</groupId>
	<artifactId>hbase</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>hbase</name>
	<url>http://maven.apache.org</url>
	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.apache.hbase</groupId>
			<artifactId>hbase-client</artifactId>
			<version>2.1.0</version>
		</dependency>
		<dependency>
			<groupId>commons-io</groupId>
			<artifactId>commons-io</artifactId>
			<version>2.6</version>
		</dependency>
		<!-- hadoop的通用包 -->
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-common</artifactId>
			<version>2.7.5</version>
		</dependency>

		<!-- Xml操作相关 -->
		<dependency>
			<groupId>com.github.cloudecho</groupId>
			<artifactId>xmlbean</artifactId>
			<version>1.5.5</version>
		</dependency>
		<!-- 操作Office库 -->
		<dependency>
			<groupId>org.apache.poi</groupId>
			<artifactId>poi</artifactId>
			<version>4.0.1</version>
		</dependency>
		<dependency>
			<groupId>org.apache.poi</groupId>
			<artifactId>poi-ooxml</artifactId>
			<version>4.0.1</version>
		</dependency>
		<dependency>
			<groupId>org.apache.poi</groupId>
			<artifactId>poi-ooxml-schemas</artifactId>
			<version>4.0.1</version>
		</dependency>
		<!-- 操作JSON -->
		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>fastjson</artifactId>
			<version>1.2.62</version>
		</dependency>

		<!-- phoenix core -->
		<dependency>
			<groupId>org.apache.phoenix</groupId>
			<artifactId>phoenix-core</artifactId>
			<version>5.0.0-HBase-2.0</version>
			<!-- 解决打包 Failure to find org.glassfish:javax.el:pom:3.0.1-b08-SNAPSHOT in xxx -->
			<exclusions>
                <exclusion>
                    <groupId>org.glassfish</groupId>
                    <artifactId>javax.el</artifactId>
                </exclusion>
            </exclusions>
		</dependency>
		<!-- phoenix 客户端 -->
		<dependency>
			<groupId>org.apache.phoenix</groupId>
			<artifactId>phoenix-queryserver-client</artifactId>
			<version>5.0.0-HBase-2.0</version>
			<!-- 解决打包 Failure to find org.glassfish:javax.el:pom:3.0.1-b08-SNAPSHOT in xxx -->
			<exclusions>
                <exclusion>
                    <groupId>org.glassfish</groupId>
                    <artifactId>javax.el</artifactId>
                </exclusion>
            </exclusions>
		</dependency>

		<!-- HBase对mapreduce的支持 -->
		<dependency>
			<groupId>org.apache.hbase</groupId>
			<artifactId>hbase-mapreduce</artifactId>
			<version>2.1.0</version>
		</dependency>
		<!-- hadoop mr任务客户端 -->
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-mapreduce-client-jobclient</artifactId>
			<version>2.7.5</version>
		</dependency>
		<!-- 客户端 -->
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-mapreduce-client-core</artifactId>
			<version>2.7.5</version>
		</dependency>
		<!-- hadoop权限认证相关 -->
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-auth</artifactId>
			<version>2.7.5</version>
		</dependency>
		<!-- 方便操作文件apache的工具类包 -->
		<dependency>
			<groupId>commons-io</groupId>
			<artifactId>commons-io</artifactId>
			<version>2.6</version>
		</dependency>
		<dependency>
			<groupId>org.apache.htrace</groupId>
			<artifactId>htrace-core</artifactId>
			<version>3.2.0-incubating</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-core</artifactId>
			<version>2.5.6</version>
		</dependency>

		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>5.1.46</version>
		</dependency>

		<!-- ORC文件依赖 -->
		<dependency>
			<groupId>org.apache.orc</groupId>
			<artifactId>orc-shims</artifactId>
			<version>1.6.3</version>
		</dependency>
		<dependency>
			<groupId>org.apache.orc</groupId>
			<artifactId>orc-core</artifactId>
			<version>1.6.3</version>
		</dependency>
		<dependency>
			<groupId>org.apache.orc</groupId>
			<artifactId>orc-mapreduce</artifactId>
			<version>1.6.3</version>
		</dependency>
		<dependency>
			<groupId>jdk.tools</groupId>
			<artifactId>jdk.tools</artifactId>
			<version>1.8</version>
			<scope>system</scope>
			<systemPath>${JAVA_HOME}/lib/tools.jar</systemPath>
		</dependency>
	</dependencies>
	
</project>

2、将数据库中1260万数据导出成ORC文件

用到了User对象,由于是以user对象写出的数据,故需要实现hdfs要求的序列化。同时,在Hbase中解析也需要使用user,没有重复创建User,使用的是同一个User.java,Hbase解析中使用普通的User.Java即可,不需要序列化。

1)、java bean

package org.hbase.mr.largedata;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapreduce.lib.db.DBWritable;

import lombok.Data;

/**
 * 实现Hadoop序列化接口Writable 从数据库读取/写入数据库的对象应实现DBWritable
 * 
 * @author chenw
 */
@Data
public class User implements Writable, DBWritable {
	private int id;
	private String userName;
	private String password;
	private String phone;
	private String email;
	private String createDay;

	@Override
	public void write(PreparedStatement ps) throws SQLException {
		ps.setInt(1, id);
		ps.setString(2, userName);
		ps.setString(3, password);
		ps.setString(4, phone);
		ps.setString(5, email);
		ps.setString(6, createDay);
	}

	@Override
	public void readFields(ResultSet rs) throws SQLException {
		this.id = rs.getInt(1);
		this.userName = rs.getString(2);
		this.password = rs.getString(3);
		this.phone = rs.getString(4);
		this.email = rs.getString(5);
		this.createDay = rs.getString(6);
	}

	@Override
	public void write(DataOutput out) throws IOException {
		out.writeInt(id);
		out.writeUTF(userName);
		out.writeUTF(password);
		out.writeUTF(phone);
		out.writeUTF(email);
		out.writeUTF(createDay);
	}

	@Override
	public void readFields(DataInput in) throws IOException {
		id = in.readInt();
		userName = in.readUTF();
		password = in.readUTF();
		phone = in.readUTF();
		email = in.readUTF();
		createDay = in.readUTF();
	}

	public String toString() {
		return id + "\t" + userName + "\t" + password + "\t" + phone + "\t" + email + "\t" + createDay;
	}

}

2)、ReadUserFromMysqlToOrcFile.java

该类是实现将mysql数据以ORC文件形式写入HDFS中

package org.hbase.mr.largedata.file;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Counter;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.db.DBConfiguration;
import org.apache.hadoop.mapreduce.lib.db.DBInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.orc.OrcConf;
import org.apache.orc.TypeDescription;
import org.apache.orc.mapred.OrcStruct;
import org.apache.orc.mapreduce.OrcOutputFormat;
import org.hbase.mr.bank.BankRecordBulkLoad;
import org.hbase.mr.largedata.User;
import org.springframework.util.StopWatch;
/**
 * 从mysql中读取user表数据,并写入orc文件
 * 
 * @author chenw
 */
public class ReadUserFromMysqlToOrcFile extends Configured implements Tool {
	private static final String SCHEMA = "struct<id:int,userName:string,password:string,phone:string,email:string,createDay:string>";
	static String out = "hdfs://HadoopHAcluster//hbasetest/user/textuser/out";

	@Override
	public int run(String[] args) throws Exception {
		OrcConf.MAPRED_OUTPUT_SCHEMA.setString(this.getConf(), SCHEMA);
		Configuration conf = getConf();

		DBConfiguration.configureDB(conf, "com.mysql.jdbc.Driver", "jdbc:mysql://192.168.10.44:3306/test", "root",
				"root");

		Job job = Job.getInstance(conf, this.getClass().getSimpleName());
		job.setJarByClass(this.getClass());

		job.setInputFormatClass(DBInputFormat.class);
		DBInputFormat.setInput(job, User.class, "select id, user_Name,pass_word,phone,email,create_day from dx_user",
				// 12606948 条数据
				"select count(*) from dx_user ");

//		DBInputFormat.setInput(job, User.class,
//				"select id, user_Name,pass_word,phone,email,create_day from dx_user where user_name = 'alan2452'",
//				"select count(*) from dx_user where user_name = 'alan2452'");

		Path outputDir = new Path(out);
		outputDir.getFileSystem(this.getConf()).delete(outputDir, true);
		FileOutputFormat.setOutputPath(job, outputDir);

		job.setMapperClass(ReadUserFromMysqlToOrcFileMapper.class);
		job.setMapOutputKeyClass(NullWritable.class);
		job.setMapOutputValueClass(OrcStruct.class);
		job.setOutputFormatClass(OrcOutputFormat.class);

		job.setNumReduceTasks(0);

		return job.waitForCompletion(true) ? 0 : 1;
	}

	public static void main(String[] args) throws Exception {
		StopWatch clock = new StopWatch();
		clock.start(BankRecordBulkLoad.class.getSimpleName());
		
		// 1. 使用HBaseConfiguration.create()加载配置文件
		System.setProperty("HADOOP_USER_NAME", "alanchan");
		Configuration conf = new Configuration();
		conf.set("fs.defaultFS", "hdfs://HadoopHAcluster");
		conf.set("dfs.nameservices", "HadoopHAcluster");
		conf.set("dfs.ha.namenodes.HadoopHAcluster", "nn1,nn2");
		conf.set("dfs.namenode.rpc-address.HadoopHAcluster.nn1", "server1:8020");
		conf.set("dfs.namenode.rpc-address.HadoopHAcluster.nn2", "server2:8020");
		conf.set("dfs.client.failover.proxy.provider.HadoopHAcluster","org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider");
		
		int status = ToolRunner.run(conf, new ReadUserFromMysqlToOrcFile(), args);
		System.exit(status);

		clock.stop();
		System.out.println(clock.prettyPrint());
	}

	static class ReadUserFromMysqlToOrcFileMapper extends Mapper<LongWritable, User, NullWritable, OrcStruct> {
		// 获取字段描述信息
				private TypeDescription schema = TypeDescription.fromString(SCHEMA);
				// 构建输出的Key
				private final NullWritable outKey = NullWritable.get();
				// 构建输出的Value为ORCStruct类型
				private final OrcStruct outValue = (OrcStruct) OrcStruct.createValue(schema);

				protected void map(LongWritable key, User value, Context context) throws IOException, InterruptedException {
					Counter counter = context.getCounter("mysql_records_counters", "User Records");
					counter.increment(1);

					// 将所有字段赋值给Value中的列
					outValue.setFieldValue(0, new IntWritable(value.getId()));
					outValue.setFieldValue(1, new Text(value.getUserName()));
					outValue.setFieldValue(2, new Text(value.getPassword()));
					outValue.setFieldValue(3, new Text(value.getPhone()));
					outValue.setFieldValue(4, new Text(value.getEmail()));
					outValue.setFieldValue(5, new Text(value.getCreateDay()));

					context.write(outKey, outValue);
				}
	}
}

3、解析ORC文件成爲Hbase導入所需的文件

即滿足Hbase導入需要的key-value格式 Mapper<NullWritable, OrcStruct, ImmutableBytesWritable, MapReduceExtendedCell>

package org.hbase.mr.largedata.file;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.RegionLocator;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.HFileOutputFormat2;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.MapReduceExtendedCell;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.orc.mapred.OrcStruct;
import org.apache.orc.mapreduce.OrcInputFormat;
import org.hbase.mr.largedata.User;
import org.springframework.util.StopWatch;

/**
 * 将HDFS上的ORC文件解析成Hbase导入所需文件,即须与Hbase导入文件的key-value保持一致
 * @author chenw
 *
 */
public class UserBulkLoadTextToHbase extends Configured implements Tool {
	static String in = "hdfs://HadoopHAcluster/hbasetest/user/textuser/out";
	static String out = "hdfs://HadoopHAcluster/hbasetest/user/textuser/data";
	TableName tableName = TableName.valueOf("USER:TEXTUSER");

	public static void main(String[] args) throws Exception {
		StopWatch clock = new StopWatch();
		clock.start(UserBulkLoadTextToHbase.class.getSimpleName());

		// 1. 使用HBaseConfiguration.create()加载配置文件
		System.setProperty("HADOOP_USER_NAME", "alanchan");

		Configuration configuration = HBaseConfiguration.create();
		configuration.set("fs.defaultFS", "hdfs://HadoopHAcluster");
		configuration.set("dfs.nameservices", "HadoopHAcluster");
		configuration.set("dfs.ha.namenodes.HadoopHAcluster", "nn1,nn2");
		configuration.set("dfs.namenode.rpc-address.HadoopHAcluster.nn1", "server1:8020");
		configuration.set("dfs.namenode.rpc-address.HadoopHAcluster.nn2", "server2:8020");
		configuration.set("dfs.client.failover.proxy.provider.HadoopHAcluster","org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider");

		int status = ToolRunner.run(configuration, new UserBulkLoadTextToHbase(), args);
		System.exit(status);

		clock.stop();
		System.out.println(clock.prettyPrint());
	}

	@Override
	public int run(String[] args) throws Exception {
		// 2. 创建HBase连接
		Connection connection = ConnectionFactory.createConnection(getConf());
		// 3. 获取HTable
		Table table = connection.getTable(tableName);

		Job job = Job.getInstance(getConf(), this.getClass().getName());
		job.setJarByClass(this.getClass());

		job.setMapperClass(UserBulkLoadTextToHbaseMapper.class);
		job.setMapOutputKeyClass(ImmutableBytesWritable.class);
		job.setMapOutputValueClass(MapReduceExtendedCell.class);

		FileInputFormat.addInputPath(job, new Path(in));
		job.setInputFormatClass(OrcInputFormat.class);
		Path outputDir = new Path(out);
		outputDir.getFileSystem(this.getConf()).delete(outputDir, true);
		FileOutputFormat.setOutputPath(job, outputDir);

		RegionLocator regionLocator = connection.getRegionLocator(tableName);
		HFileOutputFormat2.configureIncrementalLoad(job, table, regionLocator);

		return job.waitForCompletion(true) ? 0 : 1;
	}

	/**
	 * 读取orc文件,并写成hbase文件
	 * 
	 * @author chenw
	 *
	 */
	static class UserBulkLoadTextToHbaseMapper
			extends Mapper<NullWritable, OrcStruct, ImmutableBytesWritable, MapReduceExtendedCell> {
		User orcUser = new User();

		protected void map(NullWritable key, OrcStruct value, Context context)
				throws IOException, InterruptedException {
			// 1、从orc文件中解析user
			// SCHEMA ="struct<id:int,userName:string,password:string,phone:string,email:string,createDay:string>";
			orcUser.setId(Integer.parseInt(value.getFieldValue("id").toString()));
			orcUser.setUserName(value.getFieldValue("userName").toString());
			orcUser.setPassword(value.getFieldValue("password").toString());
			orcUser.setPhone(value.getFieldValue("phone").toString());
			orcUser.setEmail(value.getFieldValue("email").toString());
			orcUser.setCreateDay(value.getFieldValue("createDay").toString());

			// 2、 从实体类中获取ID,并转换为rowkey,hbase中的字段设置为大写,为phoenix建索引奠定基础
			String rowkeyString = String.valueOf(orcUser.getId() + "-" + orcUser.getUserName());
			byte[] rowkeyByteArray = Bytes.toBytes(rowkeyString);
			byte[] columnFamily = Bytes.toBytes("C1");
			byte[] colId = Bytes.toBytes("ID");
			byte[] colUserName = Bytes.toBytes("USERNAME");
			byte[] colPassword = Bytes.toBytes("PASSWORD");
			byte[] colPhone = Bytes.toBytes("PHONE");
			byte[] colEmail = Bytes.toBytes("EMAIL");
			byte[] colCreateDay = Bytes.toBytes("CREATEDAY");

			// 3、 构建输出key:new ImmutableBytesWrite(rowkey)
			ImmutableBytesWritable immutableBytesWritable = new ImmutableBytesWritable(rowkeyByteArray);

			// 4、 使用KeyValue类构建单元格,每个需要写入到表中的字段都需要构建出来单元格
			KeyValue kvId = new KeyValue(rowkeyByteArray, columnFamily, colId, Bytes.toBytes(orcUser.getId()));
			KeyValue kvUserName = new KeyValue(rowkeyByteArray, columnFamily, colUserName,Bytes.toBytes(orcUser.getUserName()));
			KeyValue kvPassword = new KeyValue(rowkeyByteArray, columnFamily, colPassword,Bytes.toBytes(orcUser.getPassword()));
			KeyValue kvPhone = new KeyValue(rowkeyByteArray, columnFamily, colPhone, Bytes.toBytes(orcUser.getPhone()));
			KeyValue kvEmail = new KeyValue(rowkeyByteArray, columnFamily, colEmail, Bytes.toBytes(orcUser.getEmail()));
			KeyValue kvCreateDay = new KeyValue(rowkeyByteArray, columnFamily, colCreateDay,Bytes.toBytes(orcUser.getCreateDay()));

			// 5、使用context.write将输出输出
			// 构建输出的value:new MapReduceExtendedCell(keyvalue对象)
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvId));
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvUserName));
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvPassword));
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvPhone));
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvEmail));
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvCreateDay));

		}
	}
}

4、创建hbase表

在hbase shell命令下

1)、創建namespace

create_namespace "USER"

2)、創建表

create "USER:TEXTUSER", { NAME => "C1", COMPRESSION => "GZ"}, { NUMREGIONS => 6, SPLITALGO => "HexStringSplit"}

--- 可以查看数据量
hbase org.apache.hadoop.hbase.mapreduce.RowCounter 'USER:TEXTUSER'
-- 或
count 'USER:TEXTUSER'

5、加载数据文件到Hbase

生成ORC文件可以在本地的Eclipse中执行,解析ORC文件在Hadoop环境中执行

1)、打包

mvn package clean -Dmaven.test.skip=true mvn package -Dmaven.test.skip=true 执行。加载数据文件到Hbase后,会自动删除列蔟下的数据文件 hadoop jar hbase-0.0.1-SNAPSHOT.jar org.hbase.mr.largedata.file.UserBulkLoadTextToHbase

2)、导入Hbase

#hbase集群中任何一个机器上执行
hbase org.apache.hadoop.hbase.tool.LoadIncrementalHFiles /hbasetest/user/textuser/data USER:TEXTUSER

#Hbase shell客户端执行
scan 'USER:TEXTUSER', {LIMIT => 3, FORMATTER => 'toString'}

hbase(main):004:0> scan 'USER:TEXTUSER', {LIMIT => 3, FORMATTER => 'toString'}
ROW                                                              COLUMN+CELL                                                                                                                                                                                   
 1000000054-alan13256                                            column=C1:CREATEDAY, timestamp=1665400322587, value=2021-12-27 00:00:00.0                                                                                                                     
 1000000054-alan13256                                            column=C1:EMAIL, timestamp=1665400322587, value=alan.chan.chn@163.com                                                                                                                         
 1000000054-alan13256                                            column=C1:ID, timestamp=1665400322587, value=;��6                                                                                                                                             
 1000000054-alan13256                                            column=C1:PASSWORD, timestamp=1665400322587, value=256835                                                                                                                                     
 1000000054-alan13256                                            column=C1:PHONE, timestamp=1665400322587, value=13977776789                                                                                                                                   
 1000000054-alan13256                                            column=C1:USERNAME, timestamp=1665400322587, value=alan13256                                                                                                                                  
 1000000117-alan450672                                           column=C1:CREATEDAY, timestamp=1665400322587, value=2021-12-25 00:00:00.0                                                                                                                     
 1000000117-alan450672                                           column=C1:EMAIL, timestamp=1665400322587, value=alan.chan.chn@163.com                                                                                                                         
 1000000117-alan450672                                           column=C1:ID, timestamp=1665400322587, value=;��u                                                                                                                                             
 1000000117-alan450672                                           column=C1:PASSWORD, timestamp=1665400322587, value=12037                                                                                                                                      
 1000000117-alan450672                                           column=C1:PHONE, timestamp=1665400322587, value=13977776789                                                                                                                                   
 1000000117-alan450672                                           column=C1:USERNAME, timestamp=1665400322587, value=alan450672                                                                                                                                 
 1000000402-alan437180                                           column=C1:CREATEDAY, timestamp=1665400322587, value=2021-12-28 00:00:00.0                                                                                                                     
 1000000402-alan437180                                           column=C1:EMAIL, timestamp=1665400322587, value=alan.chan.chn@163.com                                                                                                                         
 1000000402-alan437180                                           column=C1:ID, timestamp=1665400322587, value=;�˒                                                                                                                                              
 1000000402-alan437180                                           column=C1:PASSWORD, timestamp=1665400322587, value=243547                                                                                                                                     
 1000000402-alan437180                                           column=C1:PHONE, timestamp=1665400322587, value=13977776789                                                                                                                                   
 1000000402-alan437180                                           column=C1:USERNAME, timestamp=1665400322587, value=alan437180                                                                                                                                 
3 row(s)
Took 0.1448 seconds

6、创建phoenix视图

CREATE view USER.TEXTUSER
(
ID varchar primary key,
C1.username varchar,
C1.password varchar,
C1.phone varchar,
C1.email varchar,
C1.createday varchar
);

0: jdbc:phoenix:server2:2118> CREATE view USER.TEXTUSER
. . . . . . . . . . . . . . > (
. . . . . . . . . . . . . . > ID varchar primary key,
. . . . . . . . . . . . . . > C1.username varchar,
. . . . . . . . . . . . . . > C1.password varchar,
. . . . . . . . . . . . . . > C1.phone varchar,
. . . . . . . . . . . . . . > C1.email varchar,
. . . . . . . . . . . . . . > C1.createday varchar
. . . . . . . . . . . . . . > );
No rows affected (7.495 seconds)

7、验证

#phoenix客户端查询
0: jdbc:phoenix:server2:2118> select * from user.textuser limit 10 offset 0;
+------------------------+-------------+-----------+--------------+------------------------+------------------------+
|           ID           |  USERNAME   | PASSWORD  |    PHONE     |         EMAIL          |       CREATEDAY        |
+------------------------+-------------+-----------+--------------+------------------------+------------------------+
| 1000000054-alan13256   | alan13256   | 256835    | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
| 1000000117-alan450672  | alan450672  | 12037     | 13977776789  | alan.chan.chn@163.com  | 2021-12-25 00:00:00.0  |
| 1000000402-alan437180  | alan437180  | 243547    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
| 1000000504-alan61609   | alan61609   | 572447    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
| 1000000600-alan4646    | alan4646    | 385328    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
| 1000000764-alan784307  | alan784307  | 487422    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
| 1000000801-alan843250  | alan843250  | 823528    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
| 100000101-alan44825    | alan44825   | 245584    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
| 1000001254-alan93950   | alan93950   | 136182    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
| 1000001554-alan66194   | alan66194   | 145151    | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
+------------------------+-------------+-----------+--------------+------------------------+------------------------+
10 rows selected (0.038 seconds)

0: jdbc:phoenix:server2:2118> select count(*) from user.textuser;
+-----------+
| COUNT(1)  |
+-----------+
| 12606948  |
+-----------+
1 row selected (27.625 seconds)
0: jdbc:phoenix:server2:2118> select * from user.textuser where id = '1000000054-alan13256';
+-----------------------+------------+-----------+--------------+------------------------+------------------------+
|          ID           |  USERNAME  | PASSWORD  |    PHONE     |         EMAIL          |       CREATEDAY        |
+-----------------------+------------+-----------+--------------+------------------------+------------------------+
| 1000000054-alan13256  | alan13256  | 256835    | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
+-----------------------+------------+-----------+--------------+------------------------+------------------------+
1 row selected (0.112 seconds)

0: jdbc:phoenix:server2:2118> select * from user.textuser where id like '%alan66194' limit 10 offset 0;
+-----------------------+------------+-----------+--------------+------------------------+------------------------+
|          ID           |  USERNAME  | PASSWORD  |    PHONE     |         EMAIL          |       CREATEDAY        |
+-----------------------+------------+-----------+--------------+------------------------+------------------------+
| 1000001554-alan66194  | alan66194  | 145151    | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
| 1007666086-alan66194  | alan66194  | 385075    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
| 1043676715-alan66194  | alan66194  | 88428     | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
| 1047614567-alan66194  | alan66194  | 464386    | 13977776789  | alan.chan.chn@163.com  | 2021-12-25 00:00:00.0  |
| 1118250550-alan66194  | alan66194  | 614253    | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
| 112636207-alan66194   | alan66194  | 728351    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
| 1153887738-alan66194  | alan66194  | 604027    | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
| 1163389712-alan66194  | alan66194  | 736322    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
| 1182190352-alan66194  | alan66194  | 343481    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
| 1227886174-alan66194  | alan66194  | 425608    | 13977776789  | alan.chan.chn@163.com  | 2021-12-25 00:00:00.0  |
+-----------------------+------------+-----------+--------------+------------------------+------------------------+
10 rows selected (13.538 seconds)

8、存在的问题

1)、數據存儲分佈不均匀

在这里插入图片描述

2)、創建表分區語句

create "USER:TEXTUSER", { NAME => "C1", COMPRESSION => "GZ"}, { NUMREGIONS => 6, SPLITALGO => "HexStringSplit"}

3)、rowkey的設置語句

String rowkeyString = String.valueOf(orcUser.getId() + "-" + orcUser.getUserName());

4)、原因

由於userID是順序生成的,username也是順序生成的,故存在分區數據存在熱點數據。

5)、解決方法

避免數據熱點出現,需要重新進行rowkey設計,避免因爲rowkey設計不當而造成的數據分區不均情況。

  • ROWKEY设计 之前rowkey=id-username,其中id是自增的,username是以alan+隨機數進行組合。如此出現了rowkey熱點,數據一半以上落入了server4。 为了确保数据均匀分布在每个Region,現重新設計rowkey。采用盡可能多的字段和不規律的字段組合的rowkey,即 rowkey = MD5Hash_id_userName_phone_createDay 以MD5Hash作为前缀,是爲了更加的分散rowkey。

  • 代碼 以下代碼為示例性,不完整

static class UserBulkLoadTextToHbaseMapper
			extends Mapper<NullWritable, OrcStruct, ImmutableBytesWritable, MapReduceExtendedCell> {
		User orcUser = new User();

		protected void map(NullWritable key, OrcStruct value, Context context) throws IOException, InterruptedException{
			// 1、从orc文件中解析user

			// 2、 从实体类中获取ID,并转换为rowkey,hbase中的字段设置为大写,为phoenix建索引奠定基础
//			String rowkeyString = String.valueOf(orcUser.getId() + "-" + orcUser.getUserName());
//			byte[] rowkeyByteArray = Bytes.toBytes(rowkeyString);
			
			// rowkey = MD5Hash_id_userName_phone_createDay
			byte[] rowkeyByteArray = getRowkey(orcUser);
			
			byte[] columnFamily = Bytes.toBytes("C1");
			byte[] colId = Bytes.toBytes("ID");
			byte[] colUserName = Bytes.toBytes("USERNAME");

			// 3、 构建输出key:new ImmutableBytesWrite(rowkey)
			ImmutableBytesWritable immutableBytesWritable = new ImmutableBytesWritable(rowkeyByteArray);

			// 4、 使用KeyValue类构建单元格,每个需要写入到表中的字段都需要构建出来单元格
			KeyValue kvId = new KeyValue(rowkeyByteArray, columnFamily, colId, Bytes.toBytes(orcUser.getId()));
			KeyValue kvUserName = new KeyValue(rowkeyByteArray, columnFamily, colUserName,Bytes.toBytes(orcUser.getUserName()));


			// 5、使用context.write将输出输出
			// 构建输出的value:new MapReduceExtendedCell(keyvalue对象)
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvId));
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvUserName));

		}
		
		protected static byte[] getRowkey(User user)  {
			// rowkey = MD5Hash_id_userName_phone_createDay
			StringBuilder rowkeyBuilder  =new StringBuilder();
			rowkeyBuilder.append(user.getId()).append("_").append(user.getUserName()).append("_").append(user.getPhone()).append("_").append(user.getCreateDay());
			// 使用Bytes.toBytes将拼接出来的字符串转换为byte[]数组
			// 使用MD5Hash.getMD5AsHex生成MD5值,并取其前8位
			String md5AsHex = MD5Hash.getMD5AsHex(rowkeyBuilder.toString().getBytes());
			String md5Hex8bit = md5AsHex.substring(0, 8);
			return Bytes.toBytes(md5Hex8bit + "_" + rowkeyBuilder.toString());
		}
	}
  • 驗證 #爲了保證環境的乾净,本次驗證是把原來的數據全部刪除做的。
1、disable "USER:TEXTUSER"
2、drop "USER:TEXTUSER"
3、修改後的代碼重新打包並上傳至hadoop的執行機器上
4、在hadoop的集群中執行
hadoop jar hbase-0.0.1-SNAPSHOT.jar org.hbase.mr.largedata.file.UserBulkLoadTextToHbase
5、在hbase的集群中執行
hbase org.apache.hadoop.hbase.tool.LoadIncrementalHFiles /hbasetest/user/textuser/data USER:TEXTUSER
6、在phoenix客戶端刪除原來創建的視圖
drop view user.textuser;
7、在phoenix客戶端創建新的視圖,執行
CREATE view USER.TEXTUSER
(
    rk varchar primary key,
    C1.id varchar,
    C1.username varchar,
    C1.password varchar,
    C1.phone varchar,
    C1.email varchar,
    C1.createday varchar
);
--注意:本次創建的視圖將id給展示出來了,上面的例子中是將id作爲rowkey,但其本身的id沒有展示。
8、查詢數據驗證
 0: jdbc:phoenix:server2:2118> select count(*) from user.textuser;
    +-----------+
    | COUNT(1)  |
    +-----------+
    | 12606948  |
    +-----------+
    1 row selected (14.285 seconds)
    0: jdbc:phoenix:server2:2118> select * from user.textuser limit 10 offset 0;
    +-------------------------------------------------------------------+-------------+-------------+-----------+--------------+------------------------+------------------------+
    |                                RK                                 |     ID      |  USERNAME   | PASSWORD  |    PHONE     |         EMAIL          |       CREATEDAY        |
    +-------------------------------------------------------------------+-------------+-------------+-----------+--------------+------------------------+------------------------+
    | 000000fd_918381146_alan82312_13977776789_2021-12-27 00:00:00.0    | 918381146   | alan82312   | 836314    | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
    | 00000280_1180368562_alan55153_13977776789_2021-12-28 00:00:00.0   | 1180368562  | alan55153   | 60528     | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
    | 00000480_744323608_alan137521_13977776789_2021-12-25 00:00:00.0   | 744323608   | alan137521  | 331676    | 13977776789  | alan.chan.chn@163.com  | 2021-12-25 00:00:00.0  |
    | 00000881_986701072_alan497509_13977776789_2021-12-28 00:00:00.0   | 986701072   | alan497509  | 215848    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
    | 000008f4_135235830_alan35114_13977776789_2021-12-27 00:00:00.0    | 135235830   | alan35114   | 477605    | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
    | 00000a92_410303526_alan70416_13977776789_2021-12-28 00:00:00.0    | 410303526   | alan70416   | 872724    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
    | 00000cb5_1038678143_alan807323_13977776789_2021-12-28 00:00:00.0  | 1038678143  | alan807323  | 307677    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
    | 0000105a_1026241491_alan6285_13977776789_2021-12-28 00:00:00.0    | 1026241491  | alan6285    | 363475    | 13977776789  | alan.chan.chn@163.com  | 2021-12-28 00:00:00.0  |
    | 000011c2_471466237_alan486814_13977776789_2021-12-25 00:00:00.0   | 471466237   | alan486814  | 378424    | 13977776789  | alan.chan.chn@163.com  | 2021-12-25 00:00:00.0  |
    | 00001251_1170378231_alan8566_13977776789_2021-12-27 00:00:00.0    | 1170378231  | alan8566    | 4626      | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
    +-------------------------------------------------------------------+-------------+-------------+-----------+--------------+------------------------+------------------------+
    10 rows selected (0.025 seconds)
    0: jdbc:phoenix:server2:2118> select * from user.textuser where id ='918381146';
    +-----------------------------------------------------------------+------------+------------+-----------+--------------+------------------------+------------------------+
    |                               RK                                |     ID     |  USERNAME  | PASSWORD  |    PHONE     |         EMAIL          |       CREATEDAY        |
    +-----------------------------------------------------------------+------------+------------+-----------+--------------+------------------------+------------------------+
    | 000000fd_918381146_alan82312_13977776789_2021-12-27 00:00:00.0  | 918381146  | alan82312  | 836314    | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
    +-----------------------------------------------------------------+------------+------------+-----------+--------------+------------------------+------------------------+
    1 row selected (18.297 seconds)
    0: jdbc:phoenix:server2:2118> select * from user.textuser where id ='918381146';
    +-----------------------------------------------------------------+------------+------------+-----------+--------------+------------------------+------------------------+
    |                               RK                                |     ID     |  USERNAME  | PASSWORD  |    PHONE     |         EMAIL          |       CREATEDAY        |
    +-----------------------------------------------------------------+------------+------------+-----------+--------------+------------------------+------------------------+
    | 000000fd_918381146_alan82312_13977776789_2021-12-27 00:00:00.0  | 918381146  | alan82312  | 836314    | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
    +-----------------------------------------------------------------+------------+------------+-----------+--------------+------------------------+------------------------+
    1 row selected (21.486 seconds)
    0: jdbc:phoenix:server2:2118> select * from user.textuser where rk = '00001251_1170378231_alan8566_13977776789_2021-12-27 00:00:00.0';
    +-----------------------------------------------------------------+-------------+-----------+-----------+--------------+------------------------+------------------------+
    |                               RK                                |     ID      | USERNAME  | PASSWORD  |    PHONE     |         EMAIL          |       CREATEDAY        |
    +-----------------------------------------------------------------+-------------+-----------+-----------+--------------+------------------------+------------------------+
    | 00001251_1170378231_alan8566_13977776789_2021-12-27 00:00:00.0  | 1170378231  | alan8566  | 4626      | 13977776789  | alan.chan.chn@163.com  | 2021-12-27 00:00:00.0  |
    +-----------------------------------------------------------------+-------------+-----------+-----------+--------------+------------------------+------------------------+
    1 row selected (0.019 seconds)
9、驗證數據在regionserver中是否分佈均匀,可見分佈非常均匀。見下圖
10、數據的應用

由上面查詢的結果可以看到,通過rowkey查詢非常快,但通過本身的id查詢則非常的慢。如此與我們設想一致,因爲hbase只針對rowkey有索引創建,但其他的字段并沒有索引創建。 爲了解決其他的字段查詢數據,可以使用hpoenix客戶端創建二級索引進行查詢。

在这里插入图片描述

  • 源碼(UserBulkLoadTextToHbase.java) 本處只調整了rowkey的部分,其他的沒有變化,故下面是調整部分的代碼,其他的參考本文上面的部分。
package org.hbase.mr.largedata.file;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.RegionLocator;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.HFileOutputFormat2;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.MD5Hash;
import org.apache.hadoop.hbase.util.MapReduceExtendedCell;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.orc.mapred.OrcStruct;
import org.apache.orc.mapreduce.OrcInputFormat;
import org.hbase.mr.largedata.User;
import org.springframework.util.StopWatch;

/**
 * 将HDFS上的ORC文件解析成Hbase导入所需文件,即须与Hbase导入文件的key-value保持一致
 * @author chenw
 *
 */
public class UserBulkLoadTextToHbase extends Configured implements Tool {
	static String in = "hdfs://HadoopHAcluster/hbasetest/user/textuser/out";
	static String out = "hdfs://HadoopHAcluster/hbasetest/user/textuser/data";
	TableName tableName = TableName.valueOf("USER:TEXTUSER");

	public static void main(String[] args) throws Exception {
		StopWatch clock = new StopWatch();
		clock.start(UserBulkLoadTextToHbase.class.getSimpleName());

		// 1. 使用HBaseConfiguration.create()加载配置文件
		System.setProperty("HADOOP_USER_NAME", "alanchan");

		Configuration configuration = HBaseConfiguration.create();
		configuration.set("fs.defaultFS", "hdfs://HadoopHAcluster");
		configuration.set("dfs.nameservices", "HadoopHAcluster");
		configuration.set("dfs.ha.namenodes.HadoopHAcluster", "nn1,nn2");
		configuration.set("dfs.namenode.rpc-address.HadoopHAcluster.nn1", "server1:8020");
		configuration.set("dfs.namenode.rpc-address.HadoopHAcluster.nn2", "server2:8020");
		configuration.set("dfs.client.failover.proxy.provider.HadoopHAcluster","org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider");

		int status = ToolRunner.run(configuration, new UserBulkLoadTextToHbase(), args);
		System.exit(status);

		clock.stop();
		System.out.println(clock.prettyPrint());
	}

	@Override
	public int run(String[] args) throws Exception {
		// 2. 创建HBase连接
		Connection connection = ConnectionFactory.createConnection(getConf());
		// 3. 获取HTable
		Table table = connection.getTable(tableName);

		Job job = Job.getInstance(getConf(), this.getClass().getName());
		job.setJarByClass(this.getClass());

		job.setMapperClass(UserBulkLoadTextToHbaseMapper.class);
		job.setMapOutputKeyClass(ImmutableBytesWritable.class);
		job.setMapOutputValueClass(MapReduceExtendedCell.class);

		FileInputFormat.addInputPath(job, new Path(in));
		job.setInputFormatClass(OrcInputFormat.class);
		Path outputDir = new Path(out);
		outputDir.getFileSystem(this.getConf()).delete(outputDir, true);
		FileOutputFormat.setOutputPath(job, outputDir);

		RegionLocator regionLocator = connection.getRegionLocator(tableName);
		HFileOutputFormat2.configureIncrementalLoad(job, table, regionLocator);

		return job.waitForCompletion(true) ? 0 : 1;
	}

	/**
	 * 读取orc文件,并写成hbase文件
	 * 
	 * @author chenw
	 *
	 */
	static class UserBulkLoadTextToHbaseMapper
			extends Mapper<NullWritable, OrcStruct, ImmutableBytesWritable, MapReduceExtendedCell> {
		User orcUser = new User();

		protected void map(NullWritable key, OrcStruct value, Context context) throws IOException, InterruptedException{
			// 1、从orc文件中解析user
			// SCHEMA ="struct<id:int,userName:string,password:string,phone:string,email:string,createDay:string>";
			orcUser.setId(value.getFieldValue("id").toString());
			orcUser.setUserName(value.getFieldValue("userName").toString());
			orcUser.setPassword(value.getFieldValue("password").toString());
			orcUser.setPhone(value.getFieldValue("phone").toString());
			orcUser.setEmail(value.getFieldValue("email").toString());
			orcUser.setCreateDay(value.getFieldValue("createDay").toString());

			// 2、 从实体类中获取ID,并转换为rowkey,hbase中的字段设置为大写,为phoenix建索引奠定基础
//			String rowkeyString = String.valueOf(orcUser.getId() + "-" + orcUser.getUserName());
//			byte[] rowkeyByteArray = Bytes.toBytes(rowkeyString);
			
			// rowkey = MD5Hash_id_userName_phone_createDay
			byte[] rowkeyByteArray = getRowkey(orcUser);
			
			byte[] columnFamily = Bytes.toBytes("C1");
			byte[] colId = Bytes.toBytes("ID");
			byte[] colUserName = Bytes.toBytes("USERNAME");
			byte[] colPassword = Bytes.toBytes("PASSWORD");
			byte[] colPhone = Bytes.toBytes("PHONE");
			byte[] colEmail = Bytes.toBytes("EMAIL");
			byte[] colCreateDay = Bytes.toBytes("CREATEDAY");

			// 3、 构建输出key:new ImmutableBytesWrite(rowkey)
			ImmutableBytesWritable immutableBytesWritable = new ImmutableBytesWritable(rowkeyByteArray);

			// 4、 使用KeyValue类构建单元格,每个需要写入到表中的字段都需要构建出来单元格
			KeyValue kvId = new KeyValue(rowkeyByteArray, columnFamily, colId, Bytes.toBytes(orcUser.getId()));
			KeyValue kvUserName = new KeyValue(rowkeyByteArray, columnFamily, colUserName,Bytes.toBytes(orcUser.getUserName()));
			KeyValue kvPassword = new KeyValue(rowkeyByteArray, columnFamily, colPassword,Bytes.toBytes(orcUser.getPassword()));
			KeyValue kvPhone = new KeyValue(rowkeyByteArray, columnFamily, colPhone, Bytes.toBytes(orcUser.getPhone()));
			KeyValue kvEmail = new KeyValue(rowkeyByteArray, columnFamily, colEmail, Bytes.toBytes(orcUser.getEmail()));
			KeyValue kvCreateDay = new KeyValue(rowkeyByteArray, columnFamily, colCreateDay,Bytes.toBytes(orcUser.getCreateDay()));

			// 5、使用context.write将输出输出
			// 构建输出的value:new MapReduceExtendedCell(keyvalue对象)
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvId));
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvUserName));
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvPassword));
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvPhone));
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvEmail));
			context.write(immutableBytesWritable, new MapReduceExtendedCell(kvCreateDay));

		}
		
		protected static byte[] getRowkey(User user)  {
			// rowkey = MD5Hash_id_userName_phone_createDay
			StringBuilder rowkeyBuilder  =new StringBuilder();
			rowkeyBuilder.append(user.getId()).append("_").append(user.getUserName()).append("_").append(user.getPhone()).append("_").append(user.getCreateDay());
			
			// 使用Bytes.toBytes将拼接出来的字符串转换为byte[]数组
			// 使用MD5Hash.getMD5AsHex生成MD5值,并取其前8位
			String md5AsHex = MD5Hash.getMD5AsHex(rowkeyBuilder.toString().getBytes());
			String md5Hex8bit = md5AsHex.substring(0, 8);

			return Bytes.toBytes(md5Hex8bit + "_" + rowkeyBuilder.toString());
		}
	}
}

实际使用过程中,可以直接根据rowkey查询(因为rowkey的生成规则是已知的,查询时可以构造rowkey进行查询),其他字段可以根据需要进行查询或创建二级索引进行查询。

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2024-05-31