hive实例化schema报错： Failed to get schema version.

具体报错：

Metastore connection URL:     jdbc:mysql://hm02:3306/hive?createDatabaseIfNotExist=true
Metastore Connection Driver :     com.mysql.cj.jdbc.Driver
Metastore connection User:     hive
org.apache.hadoop.hive.metastore.HiveMetaException: Failed to get schema version.
Underlying cause: com.mysql.cj.jdbc.exceptions.CommunicationsException : Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
SQL Error code: 0
Use --verbose for detailed stacktrace.
*** schemaTool failed ***

原因及解决方案： 

说来惭愧，自己都想打自己（这个问题困扰了我一整天），出错是因为我跟着别人的教程配置，在配置hive/conf/hive-site.xml的时候,javax.jdo.option.ConnectionURL没有改成自己的，用的别人的所以报错：

解决方案：

注意：下面标红的位置要特别注意用自己的

修改hive配置文件： hive/conf/hive-site.xml：

     
        javax.jdo.option.ConnectionURL
        jdbc:mysql://192.168..129.105:3306/hive?createDatabaseIfNotExist=true  
    
    
        javax.jdo.option.ConnectionDriverName
        com.mysql.cj.jdbc.Driver
    
    
        javax.jdo.option.ConnectionUserName
        hive   
    
    
        javax.jdo.option.ConnectionPassword
        123456 
    
   
        hive.metastore.schema.verification
        false
    

 

如果还是不行，应该是对应用户没有授权：

注释掉  /etc/mysql/mysql.conf.d/mysqld.cnf   里面的这一句    bind-address    = 127.0.0.1 

登录mysql：   mysql -u root -p

use mysql;

GRANT ALL ON *.* to 'hive'@'%' IDENTIFIED BY '123456' WITH GRANT OPTION; 

flush privileges;

quit;

重启mysql： sudo service mysql restart

重新实例化成功： ./schematool -dbType mysql -initSchema