hadoop(十二)hbase数据库+集群搭建+Api

HBASE表结构:

建表时,不需要限定表中的字段,只需要指定若干个列族

插入数据时,列族中可以存储任意多个列(KV,列名&列值)

要查询某一列具体字段的值,需要指定的坐标:列名--->行健--->列族:列名--->版本

hbase的存放策略:

一张大表切分为多个Region,Region放在多个Region Server上,Region Server将Region放在HDFS里(datanode),通常

Region Server和datanode在一台机器上

 

hbase查询(寻址机制)

略略略。

hbase集群搭建

1.上传hbase安装包

2.解压

3.配置hbase集群,要修改3个文件(首先zk集群已经安装好了)
    注意:要把hadoop的hdfs-site.xml和core-site.xml 放到hbase/conf下
    
    3.1修改hbase-env.sh
    export JAVA_HOME=/usr/java/jdk1.7.0_55
    //告诉hbase使用外部的zk
    export HBASE_MANAGES_ZK=false
    
    vim hbase-site.xml
    <configuration>
        <!-- 指定hbase在HDFS上存储的路径 -->
        <property>
                <name>hbase.rootdir</name>
                <value>hdfs://ns1/hbase</value>
        </property>
        <!-- 指定hbase是分布式的 -->
        <property>
                <name>hbase.cluster.distributed</name>
                <value>true</value>
        </property>
        <!-- 指定zk的地址,多个用“,”分割 -->
        <property>
                <name>hbase.zookeeper.quorum</name>
                <value>weekend04:2181,weekend05:2181,weekend06:2181</value>
        </property>
    </configuration>
    
    vim regionservers
    weekend03
    weekend04
    weekend05
    weekend06
    
    3.2拷贝hbase到其他节点
        scp -r /weekend/hbase-0.96.2-hadoop2/ weekend02:/weekend/
        scp -r /weekend/hbase-0.96.2-hadoop2/ weekend03:/weekend/
        scp -r /weekend/hbase-0.96.2-hadoop2/ weekend04:/weekend/
        scp -r /weekend/hbase-0.96.2-hadoop2/ weekend05:/weekend/
        scp -r /weekend/hbase-0.96.2-hadoop2/ weekend06:/weekend/
4.将配置好的HBase拷贝到每一个节点并同步时间。

5.启动所有的hbase
    分别启动zk
        ./zkServer.sh start
    启动hbase集群
        start-dfs.sh
    启动hbase,在主节点上运行:
        start-hbase.sh
6.通过浏览器访问hbase管理页面
    192.168.1.201:60010
7.为保证集群的可靠性,要启动多个HMaster
    hbase-daemon.sh start master
    


    hbase-shell

./hbase shell   进入客户端

list   查看所有的表

describe 描述表结构

put存数据

put '表名','行名','列名','值'

put '表名', '0001', 'base_info:name', 'fengjie'

put '表名', '0001', 'base_info:age', '18' 

put '表名', '0001', 'extra_info:boyfriend', 'xiaoming'

get获取数据

get '表名','0001'

用drop命令可以删除表。在删除一个表之前必须先将其禁用。

disable 'emp'
drop 'emp'

scan 'table1' 查看表数据

hbase- Java Api

import java.util.List;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.filter.BinaryComparator;
import org.apache.hadoop.hbase.filter.BinaryPrefixComparator;
import org.apache.hadoop.hbase.filter.ByteArrayComparable;
import org.apache.hadoop.hbase.filter.ColumnPrefixFilter;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.filter.FamilyFilter;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.filter.MultipleColumnPrefixFilter;
import org.apache.hadoop.hbase.filter.PrefixFilter;
import org.apache.hadoop.hbase.filter.QualifierFilter;
import org.apache.hadoop.hbase.filter.RegexStringComparator;
import org.apache.hadoop.hbase.filter.RowFilter;
import org.apache.hadoop.hbase.filter.SingleColumnValueFilter;
import org.apache.hadoop.hbase.filter.SubstringComparator;
import org.apache.hadoop.hbase.master.TableNamespaceManager;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Before;
import org.junit.Test;

public class HbaseDemo {

	private Configuration conf = null;
	
	@Before
	public void init(){
		conf = HBaseConfiguration.create();
		conf.set("hbase.zookeeper.quorum", "weekend05,weekend06,weekend07");
	}
	
	@Test
	public void testDrop() throws Exception{
		HBaseAdmin admin = new HBaseAdmin(conf);
		admin.disableTable("account");
		admin.deleteTable("account");
		admin.close();
	}
	
	@Test
	public void testPut() throws Exception{
		HTable table = new HTable(conf, "person_info");
		Put p = new Put(Bytes.toBytes("person_rk_bj_zhang_000002"));
		p.add("base_info".getBytes(), "name".getBytes(), "zhangwuji".getBytes());
		table.put(p);
		table.close();
	}
	
	@Test
	public void testGet() throws Exception{
		HTable table = new HTable(conf, "person_info");
		Get get = new Get(Bytes.toBytes("person_rk_bj_zhang_000001"));
		get.setMaxVersions(5);
		Result result = table.get(get);
		List<Cell> cells = result.listCells();
		
//			result.getValue(family, qualifier);  可以从result中直接取出一个特定的value
		
		//遍历出result中所有的键值对
		for(KeyValue kv : result.list()){
			String family = new String(kv.getFamily());
			System.out.println(family);
			String qualifier = new String(kv.getQualifier());
			System.out.println(qualifier);
			System.out.println(new String(kv.getValue()));
			
		}
		table.close();
	}
	
	/**
	 * 多种过滤条件的使用方法
	 * @throws Exception
	 */
	@Test
	public void testScan() throws Exception{
		HTable table = new HTable(conf, "person_info".getBytes());
		Scan scan = new Scan(Bytes.toBytes("person_rk_bj_zhang_000001"), Bytes.toBytes("person_rk_bj_zhang_000002"));
		
		//前缀过滤器----针对行键
		Filter filter = new PrefixFilter(Bytes.toBytes("rk"));
		
		//行过滤器
		ByteArrayComparable rowComparator = new BinaryComparator(Bytes.toBytes("person_rk_bj_zhang_000001"));
		RowFilter rf = new RowFilter(CompareOp.LESS_OR_EQUAL, rowComparator);
		
		/**
         * 假设rowkey格式为:创建日期_发布日期_ID_TITLE
         * 目标:查找  发布日期  为  2014-12-21  的数据
         */
        rf = new RowFilter(CompareOp.EQUAL , new SubstringComparator("_2014-12-21_"));
		
		
		//单值过滤器 1 完整匹配字节数组
		new SingleColumnValueFilter("base_info".getBytes(), "name".getBytes(), CompareOp.EQUAL, "zhangsan".getBytes());
		//单值过滤器2 匹配正则表达式
		ByteArrayComparable comparator = new RegexStringComparator("zhang.");
		new SingleColumnValueFilter("info".getBytes(), "NAME".getBytes(), CompareOp.EQUAL, comparator);

		//单值过滤器2 匹配是否包含子串,大小写不敏感
		comparator = new SubstringComparator("wu");
		new SingleColumnValueFilter("info".getBytes(), "NAME".getBytes(), CompareOp.EQUAL, comparator);

		//键值对元数据过滤-----family过滤----字节数组完整匹配
        FamilyFilter ff = new FamilyFilter(
                CompareOp.EQUAL , 
                new BinaryComparator(Bytes.toBytes("base_info"))   //表中不存在inf列族,过滤结果为空
                );
        //键值对元数据过滤-----family过滤----字节数组前缀匹配
        ff = new FamilyFilter(
                CompareOp.EQUAL , 
                new BinaryPrefixComparator(Bytes.toBytes("inf"))   //表中存在以inf打头的列族info,过滤结果为该列族所有行
                );
		
        
       //键值对元数据过滤-----qualifier过滤----字节数组完整匹配
        
        filter = new QualifierFilter(
                CompareOp.EQUAL , 
                new BinaryComparator(Bytes.toBytes("na"))   //表中不存在na列,过滤结果为空
                );
        filter = new QualifierFilter(
                CompareOp.EQUAL , 
                new BinaryPrefixComparator(Bytes.toBytes("na"))   //表中存在以na打头的列name,过滤结果为所有行的该列数据
        		);
		
        //基于列名(即Qualifier)前缀过滤数据的ColumnPrefixFilter
        filter = new ColumnPrefixFilter("na".getBytes());
        
        //基于列名(即Qualifier)多个前缀过滤数据的MultipleColumnPrefixFilter
        byte[][] prefixes = new byte[][] {Bytes.toBytes("na"), Bytes.toBytes("me")};
        filter = new MultipleColumnPrefixFilter(prefixes);
 
        //为查询设置过滤条件
        scan.setFilter(filter);
        
        
		scan.addFamily(Bytes.toBytes("base_info"));
		ResultScanner scanner = table.getScanner(scan);
		for(Result r : scanner){
			/**
			for(KeyValue kv : r.list()){
				String family = new String(kv.getFamily());
				System.out.println(family);
				String qualifier = new String(kv.getQualifier());
				System.out.println(qualifier);
				System.out.println(new String(kv.getValue()));
			}
			*/
			//直接从result中取到某个特定的value
			byte[] value = r.getValue(Bytes.toBytes("base_info"), Bytes.toBytes("name"));
			System.out.println(new String(value));
		}
		table.close();
	}
	
	
	@Test
	public void testDel() throws Exception{
		HTable table = new HTable(conf, "user");
		Delete del = new Delete(Bytes.toBytes("rk0001"));
		del.deleteColumn(Bytes.toBytes("data"), Bytes.toBytes("pic"));
		table.delete(del);
		table.close();
	}
	
	
	
	
	public static void main(String[] args) throws Exception {
		Configuration conf = HBaseConfiguration.create();
//		conf.set("hbase.zookeeper.quorum", "weekend05:2181,weekend06:2181,weekend07:2181");
		HBaseAdmin admin = new HBaseAdmin(conf);
		
		TableName tableName = TableName.valueOf("person_info");
		HTableDescriptor td = new HTableDescriptor(tableName);
		HColumnDescriptor cd = new HColumnDescriptor("base_info");
		cd.setMaxVersions(10);
		td.addFamily(cd);
		admin.createTable(td);
		
		admin.close();

	}
	
	

}

    
    
 

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