Issue

• A MySQL datasource is configured with a failover URL (e.g. <connection-url>jdbc:mysql://192.168.1.2,192.168.1.3/mydb</connection-url>)
• After enabling fault tolerance using the MySQLValidConnectionChecker, an exception is raised on every validation attempt

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
        ...
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:377)
        at com.mysql.jdbc.Util.getInstance(Util.java:360)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:935)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:924)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:870)
        at com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1232)
        at com.mysql.jdbc.LoadBalancingConnectionProxy.doPing(LoadBalancingConnectionProxy.java:827)
        at com.mysql.jdbc.LoadBalancedMySQLConnection.ping(LoadBalancedMySQLConnection.java:2086)
        at com.mysql.jdbc.LoadBalancedMySQLConnection.ping(LoadBalancedMySQLConnection.java:2081)
        ...
        at com.mysql.jdbc.LoadBalancingConnectionProxy.invoke(LoadBalancingConnectionProxy.java:563)
        at com.mysql.jdbc.FailoverConnectionProxy.invoke(FailoverConnectionProxy.java:132)
        ...