服务器运行一直报这个错

```
2016-01-20 15:21:55,657 [Druid-ConnectionPool-Destroy-1741624376] DEBUG com.alibaba.druid.util.JdbcUtils - close connection error
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Communications link failure during rollback(). Transaction resolution unknown.
at sun.reflect.GeneratedConstructorAccessor239.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1015)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:975)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:920)
at com.mysql.jdbc.ConnectionImpl.rollback(ConnectionImpl.java:5062)
at com.mysql.jdbc.ConnectionImpl.realClose(ConnectionImpl.java:4654)
at com.mysql.jdbc.ConnectionImpl.close(ConnectionImpl.java:1630)
at com.alibaba.druid.filter.FilterChainImpl.connection_close(FilterChainImpl.java:169)
at com.alibaba.druid.filter.stat.StatFilter.connection_close(StatFilter.java:254)
at com.alibaba.druid.filter.FilterChainImpl.connection_close(FilterChainImpl.java:165)
at com.alibaba.druid.proxy.jdbc.ConnectionProxyImpl.close(ConnectionProxyImpl.java:115)
at com.alibaba.druid.util.JdbcUtils.close(JdbcUtils.java:83)
at com.alibaba.druid.pool.DruidDataSource.shrink(DruidDataSource.java:2152)
at com.alibaba.druid.pool.DruidDataSource$DestroyTask.run(DruidDataSource.java:1964)
at com.alibaba.druid.pool.DruidDataSource$DestroyConnectionThread.run(DruidDataSource.java:1951)

```