大数据笔记(十三)——常见的NoSQL数据库之HBase数据库(A)
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一.HBase的表结构和体系结构
1.HBase的表结构
把所有的数据存到一张表中。通过牺牲表空间,换取良好的性能。
HBase的列以列族的形式存在。每一个列族包括若干列
2.HBase的体系结构
主从结构:
主节点:HBase
从节点:RegionServer 包含多个Region,一个列族就是一个Region
HBase在ZK中保存数据
(*)配置信息、HBase集群结构信息
(*)表的元信息
(*)实现HBase的HA:high avaibility 高可用性
二.搭建HBase的本地模式和伪分布模式
1.解压:
tar -zxvf hbase-1.3.1-bin.tar.gz -C ~/training/
2.设置环境变量: vi ~/.bash_profile
HBASE_HOME=/root/training/hbase-1.3.1
export HBASE_HOME
PATH=$HBASE_HOME/bin:$PATH
export PATH
使文件生效:source ~/.bash_profile
本地模式 不需要HDFS、直接把数据存在操作系统
hbase-env.sh
export JAVA_HOME=/root/training/jdk1.8.0_144
hbase-site.xml
<property> <name>hbase.rootdir</name> <value>file:///root/training/hbase-1.3.1/data</value> </property>
伪分布模式
hbase-env.sh 添加下面这一行,使用自带的Zookeeper
export HBASE_MANAGES_ZK=true
hbase-site.xml 把本地模式的property删除,添加下列配置
<property>
<name>hbase.rootdir</name> <value>hdfs://192.168.153.11:9000/hbase</value> </property> <property> <name>hbase.cluster.distributed</name> <value>true</value> </property> <property> <!--Zookeeper的地址--> <name>hbase.zookeeper.quorum</name> <value>192.168.153.11</value> </property> <property> <!--数据冗余度--> <name>dfs.replication</name> <value>1</value> </property>
regionservers
192.168.153.11
可以在web上查看
三.搭建HBase的全分布模式和HA
在putty中设置bigdata12 bigdata13 bigdata14 时间同步:date -s 2018-03-10
主节点:hbase-site.xml
<property> <name>hbase.rootdir</name> <value>hdfs://192.168.153.12:9000/hbase</value> </property> <property> <name>hbase.cluster.distributed</name> <value>true</value> </property> <property> <name>hbase.zookeeper.quorum</name> <value>192.168.153.12</value> </property> <property> <name>dfs.replication</name> <value>2</value> </property> <property> <!--解决时间不同步的问题:允许的时间误差最大值--> <name>hbase.master.maxclockskew</name> <value>180000</value> </property>
regionservers
192.168.154.13
192.168.153.14
拷贝到13和14上:
scp -r hbase-1.3.1/ root@bigdata13:/root/training
scp -r hbase-1.3.1/ root@bigdata14:/root/training
四.HBase在Zookeeper中保存的数据和HA的实现
HA的实现:
不需要额外配置,只用在其中一个从节点上单点启动Hmaster
bigdata13:hbase-daemon.sh start master
五.操作HBase
1.Web Console网页:端口:16010
2.命令行
开启hbase: start-hbase.sh
开启hbase shell
建表:
hbase(main):001:0> create \'students\',\'info\',\'grade\' //创建表 0 row(s) in 1.7020 seconds => Hbase::Table - students hbase(main):002:0> desc \'students\' //查看表结构 Table students is ENABLED students COLUMN FAMILIES DESCRIPTION {NAME => \'grade\', BLOOMFILTER => \'ROW\', VERSIONS => \'1\', IN_MEMORY => \'false\', KEEP_DELETED_CELLS => \'FALSE\', DATA_BLOCK_ENCODIN G => \'NONE\', TTL => \'FOREVER\', COMPRESSION => \'NONE\', MIN_VERSIONS => \'0\', BLOCKCACHE => \'true\', BLOCKSIZE => \'65536\', REPLICATI ON_SCOPE => \'0\'} {NAME => \'info\', BLOOMFILTER => \'ROW\', VERSIONS => \'1\', IN_MEMORY => \'false\', KEEP_DELETED_CELLS => \'FALSE\', DATA_BLOCK_ENCODING => \'NONE\', TTL => \'FOREVER\', COMPRESSION => \'NONE\', MIN_VERSIONS => \'0\', BLOCKCACHE => \'true\', BLOCKSIZE => \'65536\', REPLICATIO N_SCOPE => \'0\'} 2 row(s) in 0.2540 seconds hbase(main):003:0> describe \'students\' Table students is ENABLED students COLUMN FAMILIES DESCRIPTION {NAME => \'grade\', BLOOMFILTER => \'ROW\', VERSIONS => \'1\', IN_MEMORY => \'false\', KEEP_DELETED_CELLS => \'FALSE\', DATA_BLOCK_ENCODIN G => \'NONE\', TTL => \'FOREVER\', COMPRESSION => \'NONE\', MIN_VERSIONS => \'0\', BLOCKCACHE => \'true\', BLOCKSIZE => \'65536\', REPLICATI ON_SCOPE => \'0\'} {NAME => \'info\', BLOOMFILTER => \'ROW\', VERSIONS => \'1\', IN_MEMORY => \'false\', KEEP_DELETED_CELLS => \'FALSE\', DATA_BLOCK_ENCODING => \'NONE\', TTL => \'FOREVER\', COMPRESSION => \'NONE\', MIN_VERSIONS => \'0\', BLOCKCACHE => \'true\', BLOCKSIZE => \'65536\', REPLICATIO N_SCOPE => \'0\'} 2 row(s) in 0.0240 seconds
desc和describe的区别:
desc是SQL*PLUS语句
describe是SQL语句
分析students表的结构
查看有哪些表:list
插入数据:put
put \'students\',\'stu001\',\'info:name\',\'Tom\' put \'students\',\'stu001\',\'info:age\',\'24\' put \'students\',\'stu001\',\'grade:math\',\'85\' put \'students\',\'stu002\',\'info:name\',\'Mary\' put \'students\',\'stu002\',\'info:age\',\'28\'
查询数据:
scan 相当于:select * from students
get 相当于 select * from students where rowkey=??
清空表中的数据
delete DML(可以回滚)
truncate DDL(不可以回滚)
补充:DDL:数据定义语言,如 create/alter/drop/truncate/comment/grant等
DML:数据操作语言,如select/delete/insert/update/explain plan等
DCL:数据控制语言,如commit/roollback
2、delete会产生碎片;truncate不会
3、delete不会释放空间;truncate会
4、delete可以闪回(flashback),truncate不可以闪回
truncate \'students\' -----> 本质: 先删除表,再重建
日志:
Truncating \'students\' table (it may take a while):
- Disabling table...
- Truncating table...
0 row(s) in 4.0840 seconds
3.JAVA API
修改etc文件:C:\\Windows\\System32\\drivers\\etc
添加一行:192.168.153.11 bigdata11
TestHBase.java
package demo; import java.io.IOException; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hbase.HColumnDescriptor; import org.apache.hadoop.hbase.HTableDescriptor; import org.apache.hadoop.hbase.MasterNotRunningException; import org.apache.hadoop.hbase.TableName; import org.apache.hadoop.hbase.ZooKeeperConnectionException; 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.util.Bytes; import org.junit.Test; import io.netty.util.internal.SystemPropertyUtil; /** * 1.需要一个jar包: hamcrest-core-1.3.jar * 2.修改windows host文件 * C:\\Windows\\System32\\drivers\\etc\\hosts * 192.168.153.11 bigdata11 * @author YOGA * */ public class TestHBase { @Test public void testCreateTable() throws Exception{ //配置ZK的地址信息 Configuration conf = new Configuration(); //hbase-site.xml文件里 conf.set("hbase.zookeeper.quorum", "192.168.153.11"); //得到HBsase客户端 HBaseAdmin client = new HBaseAdmin(conf); //创建表的描述符 HTableDescriptor htd = new HTableDescriptor(TableName.valueOf("mytable")); //添加列族 htd.addFamily(new HColumnDescriptor("info")); htd.addFamily(new HColumnDescriptor("grade")); //建表 client.createTable(htd); client.close(); } @Test public void testPut() throws Exception{ //配置ZK的地址信息 Configuration conf = new Configuration(); conf.set("hbase.zookeeper.quorum", "192.168.153.11"); //得到HTable客户端 HTable client = new HTable(conf, "mytable"); //构造一个Put对象,参数:rowKey Put put = new Put(Bytes.toBytes("id001")); //put.addColumn(family, //列族 // qualifier, //列 // value) ֵ//列对应的值 put.addColumn(Bytes.toBytes("info"), Bytes.toBytes("name"), Bytes.toBytes("Tom")); client.put(put); //client.put(List<Put>); client.close(); } @Test public void testGet() throws Exception{ //配置ZK的地址信息 Configuration conf = new Configuration(); conf.set("hbase.zookeeper.quorum", "192.168.153.11"); //得到HTable客户端 HTable client = new HTable(conf, "mytable"); //构造一个Get对象 Get get = new Get(Bytes.toBytes("id001")); //查询 Result result = client.get(get); //取出数据 String name = Bytes.toString(result.getValue(Bytes.toBytes("info"), Bytes.toBytes("name"))); System.out.println(name); client.close(); } @Test public void testScan() throws Exception{ //配置ZK的地址信息 Configuration conf = new Configuration(); conf.set("hbase.zookeeper.quorum", "192.168.153.11"); //得到HTable客户端 HTable client = new HTable(conf, "mytable"); //定义一个扫描器 Scan scan = new Scan(); //scan.setFilter(filter); 定义一个过滤器 //通过扫描器查询数据 ResultScanner rScanner = client.getScanner(scan); for (Result result : rScanner) { String name = Bytes.toString(result.getValue(Bytes.toBytes("info"), Bytes.toBytes("name"))); System.out.println(name); } } }
执行以上test,结果(最后一个)
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