hive使用mysql存储元数据

Hive 将元数据存储在 RDBMS 中，有三种模式可以连接到数据库： 
1）ingle User Mode： 此模式连接到一个 In-memory 的数据库 Derby，一般用于 Unit Test。 
2）Multi User Mode：通过网络连接到一个数据库中，是最经常使用到的模式。 
3）Remote Server Mode：用于非 Java 客户端访问元数据库，在服务器端启动一个 MetaStoreServer，客户端利用 Thrift 协议通过 MetaStoreServer 访问元数据库。 

Hive默认是采用Derby来存储其Meta信息的, 
现在我们需要修改为mysql 

1.在mysql专门为hive添加用户  

 mysql> CREATE USER 'hive'@'hive-mysql' IDENTIFIED BY 'hivepasswd';
 mysql> GRANT ALL PRIVILEGES ON *.* TO 'hive'@'hive-mysql' WITH GRANT OPTION;

2.修改配置文件conf/hive-site.xml  

 <property>
         <name>hive.metastore.localname>
         <value>truevalue>
         <description>controls whether to connect to remove metastore server or open a new metastore server in Hive Client JVMdescription>
 property>
 <property>
         <name>javax.jdo.option.ConnectionURLname>
         <value>jdbc:mysql://hive-mysql:3306/hive?createDatabaseIfNotExist=truevalue>
         <description>JDBC connect string for a JDBC metastoredescription>
 property>
 <property>
         <name>javax.jdo.option.ConnectionDriverNamename>
         <value>com.mysql.jdbc.Drivervalue>
         <description>Driver class name for a JDBC metastoredescription>
 property>
 <property>
         <name>javax.jdo.option.ConnectionUserNamename>
         <value>hivevalue>
         <description>username to use against metastore databasedescription>
 property>
 <property>
         <name>javax.jdo.option.ConnectionPasswordname>
         <value>hivepasswdvalue>
         <description>password to use against metastore databasedescription>
 property>

3.添加jdbc的jar包 

 wget http://dev.mysql.com/get/Downloads/Connector-J/mysql-connector-java-5.1.11.tar.gz/from/http://mysql.he.net/
 tar -xvzf mysql-connector-java-5.1.11.tar.gz
 cp mysql-connector-java-5.1.11/*.jar /data/soft/hive/lib

4.启动hive 

 bin/hive
 hive> show tables;

When using MySQL as a metastore I see the error "com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: Specified key was too long; max key length is 767 bytes". 

    * This is a known limitation of MySQL 5.0 and UTF8 databases. One option is to use another character set, such as 'latin1', which is known to work.