基于MySQL元数据的Hive的安装和简单測试

引言：　Hive是一种强大的数据仓库查询语言，类似SQL，本文将介绍怎样搭建Hive的开发測试环境。

1. 什么是Hive?

hive是基于Hadoop的一个数据仓库工具，能够将结构化的数据文件映射为一张数据库表，并提供简单的sql查询功能，能够将sql语句转换为MapReduce任务进行执行。 其长处是学习成本低，能够通过类SQL语句高速实现简单的MapReduce统计。不必开发专门的MapReduce应用，十分适合数据仓库的统计分析。

2.  依照Ｈive的准备条件

2.1  Hadoop集群环境已经安装完成

　2.2 本文使用Ubuntu做为开发环境(14.04)

３. 安装步骤

3.1 下载Ｈｉｖｅ包：apache-hive-0.13.1-bin.tar.gz

3.2 将其解压到/opt文件夹下

　　　tar xzvf apache-hive-0.13.1-bin.tar.gz

3.3 环境变量设置

export HIVE_HOME=/opt/apache-hive-0.13

export PATH=$PATH:$HIVE_HOME/bin

export CLASSPATH=$CLASSPATH:$HIVE_HOME/bin

3.4. 改动hive-env.xml，复制hive-env.xml.template.

# Set HADOOP_HOME to point to a specific hadoop install directory

HADOOP_HOME=/opt/hadoop-1.2.1

# Hive Configuration Directory can be controlled by:

export HIVE_CONF_DIR=/opt/apache-hive-0.13/conf

3.5 改动hive-site.xml,主要改动数据库的连接信息.

 <property>
  <name>hive.metastore.uris</name>
  <value>thrift://127.0.0.1:9083</value>
  <description>Thrift URI for the remote metastore. Used by metastore client to connect to remote metastore.</description>
</property>

<property>
  <name>javax.jdo.option.ConnectionURL</name>
  <value>jdbc:mysql://BladeStone-Laptop:3306/hive?createDatabaseIfNotExist=true</value>
  <description>JDBC connect string for a JDBC metastore</description>
</property>

<property>
  <name>javax.jdo.option.ConnectionDriverName</name>
  <value>com.mysql.jdbc.Driver</value>
  <description>Driver class name for a JDBC metastore</description>
</property>

<property>
  <name>javax.jdo.option.ConnectionUserName</name>
  <value>hive</value>
  <description>username to use against metastore database</description>
</property>

<property>
  <name>javax.jdo.option.ConnectionPassword</name>
  <value>123456</value>
  <description>password to use against metastore database</description>
</property>

3.6 安装ｍｙｓｑｌ数据库(Ubuntu系统)

sudo apt-get install mysql-server

3.7 创建mysql用户hive

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3.8 在mysql中创建hive数据库

3.9  下载mysql驱动,并将驱动拷贝到hive_home／lib类库

　　mysql-connector-java-5.1.31-bin.jar

3.10 启动Hive

3.11 在Ｈive中创建表

3.12 登录mysql。訪问hive数据库

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3.13 删除Hive中的表

3.14 登录mysql,查询TBLS中的数据

４.  总结

　通过以上的步骤，我们完整的安装了一个Hive，并通过加入和删除一张数据库表的演示，来展示了Hive和Mysql元数据库之间的关系操作。

５.  常见问题

　５.1 直接通过hive命令来启动，则会出现一下错误信息：　　　

Logging initialized using configuration in jar:file:/opt/apache-hive-0.13/lib/hive-common-0.13.1.jar!/hive-log4j.properties
Exception in thread "main" java.lang.RuntimeException: java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.metastore.HiveMetaStoreClient
	at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:346)
	at org.apache.hadoop.hive.cli.CliDriver.run(CliDriver.java:681)
	at org.apache.hadoop.hive.cli.CliDriver.main(CliDriver.java:625)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:483)
	at org.apache.hadoop.util.RunJar.main(RunJar.java:160)
Caused by: java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.metastore.HiveMetaStoreClient
	at org.apache.hadoop.hive.metastore.MetaStoreUtils.newInstance(MetaStoreUtils.java:1412)
	at org.apache.hadoop.hive.metastore.RetryingMetaStoreClient.<init>(RetryingMetaStoreClient.java:62)
	at org.apache.hadoop.hive.metastore.RetryingMetaStoreClient.getProxy(RetryingMetaStoreClient.java:72)
	at org.apache.hadoop.hive.ql.metadata.Hive.createMetaStoreClient(Hive.java:2453)
	at org.apache.hadoop.hive.ql.metadata.Hive.getMSC(Hive.java:2465)
	at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:340)
	... 7 more
Caused by: java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:408)
	at org.apache.hadoop.hive.metastore.MetaStoreUtils.newInstance(MetaStoreUtils.java:1410)
	... 12 more
Caused by: MetaException(message:Could not connect to meta store using any of the URIs provided. Most recent failure: org.apache.thrift.transport.TTransportException: java.net.ConnectException: Connection refused
	at org.apache.thrift.transport.TSocket.open(TSocket.java:185)
	at org.apache.hadoop.hive.metastore.HiveMetaStoreClient.open(HiveMetaStoreClient.java:336)
	at org.apache.hadoop.hive.metastore.HiveMetaStoreClient.<init>(HiveMetaStoreClient.java:214)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:408)
	at org.apache.hadoop.hive.metastore.MetaStoreUtils.newInstance(MetaStoreUtils.java:1410)
	at org.apache.hadoop.hive.metastore.RetryingMetaStoreClient.<init>(RetryingMetaStoreClient.java:62)
	at org.apache.hadoop.hive.metastore.RetryingMetaStoreClient.getProxy(RetryingMetaStoreClient.java:72)
	at org.apache.hadoop.hive.ql.metadata.Hive.createMetaStoreClient(Hive.java:2453)
	at org.apache.hadoop.hive.ql.metadata.Hive.getMSC(Hive.java:2465)
	at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:340)
	at org.apache.hadoop.hive.cli.CliDriver.run(CliDriver.java:681)
	at org.apache.hadoop.hive.cli.CliDriver.main(CliDriver.java:625)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:483)
	at org.apache.hadoop.util.RunJar.main(RunJar.java:160)
Caused by: java.net.ConnectException: Connection refused
	at java.net.PlainSocketImpl.socketConnect(Native Method)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:345)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
	at java.net.Socket.connect(Socket.java:589)
	at org.apache.thrift.transport.TSocket.open(TSocket.java:180)
	... 19 more
)
	at org.apache.hadoop.hive.metastore.HiveMetaStoreClient.open(HiveMetaStoreClient.java:382)
	at org.apache.hadoop.hive.metastore.HiveMetaStoreClient.<init>(HiveMetaStoreClient.java:214)
	... 17 more

　　解决的方法：　hive --service metastore , 用这条命令来启动hive。

　　5.2 配置 hive.metastore.uris

        a.不启动metastore和hiveserver服务

          直接命令行hive进入hive shell环境。然后运行show databases  报错例如以下：

             ERROR ql.Driver: FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. java.lang.RuntimeException: Unable to instantiate    org.apache.hadoop.hive.metastore.HiveMetaStoreClient

     　b.另外一种种情况

          1.配置 hive.metastore.uris

          2.启动metastore服务  hive  --service metastore

         然后直接命令行hive进入hive shell环境，然后运行show databases   



         c：第三种情况

           1.凝视配置项 hive.metastore.uris

           2.不启动metastore服务

           然后直接命令行hive进入hive shell环境。然后运行show databases