安装完hive，启动错误解决办法

安装完hive时，运行没问题，后来再次开启时出现如下问题：

hive> show databases;
FAILED: Error in metadata: javax.jdo.JDOFatalDataStoreException: 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.
NestedThrowables:
com.mysql.jdbc.exceptions.jdbc4.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.
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask

解决办法 ：把hive-site.xml文件中javax.jdo.option.ConnectionURL下面用把ip改为主机名就可以了。

这是因为我用了无线网，ip改变了。。