用MySQL做集群时的一个异常


用MySQL集群时， 报出下面的异常，  Google一番也找不到一个完整的解释， 请问这是怎么回事？2011-07-12 04:00:04,581 [schedulerFactory_Worker-6] ERROR org.hibernate.transaction.JDBCTransaction- Could not toggle autocommit
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.  Connection closed after inability to pick valid new connection during fail-over.
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:407)
        at com.mysql.jdbc.Util.getInstance(Util.java:382)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1013)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:982)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927)
        at com.mysql.jdbc.LoadBalancingConnectionProxy.invoke(LoadBalancingConnectionProxy.java:523)
        at com.mysql.jdbc.LoadBalancingConnectionProxy.invoke(LoadBalancingConnectionProxy.java:479)
        at $Proxy0.setAutoCommit(Unknown Source)
        at com.mysql.jdbc.ReplicationConnection.setAutoCommit(ReplicationConnection.java:440)