天啊，救救我吧，很迷茫的ejb问题

1.在weblogic集群和分布式环境下,这些代码会有问题吗？ 
                    DistributionVO objDistributionVO = distributionSes 
                            .readDistribution(objMovementItemVO.getBatchId());    
                    objDistributionVO.setActualQty(objDistributionVO.getActualQty() 
                            - objMovementItemVO.getQty()); 
                    objDistributionVO.setReservedQty(objDistributionVO.getReservedQty() 
                            - objMovementItemVO.getQty()); 
                    distributionSes.updateDistribution(objDistributionVO); 
                    objDistributionVO.setActualQty(objMovementItemVO.getQty()); 
                    objDistributionVO.setReservedQty(0d); 
                    objDistributionVO.setLocationId(objMovementItemVO.getToId());                     int iBatchId = distributionSes.insertDistribution(objDistributionVO); 2. objDistributionVO1 一定会是前面修改后的结果吗?? 
                DistributionVO objDistributionVO = distributionSes 
                            .readDistribution(objMovementItemVO.getBatchId()); 
                    objDistributionVO.setActualQty(objDistributionVO.getActualQty() 
                            - objMovementItemVO.getQty()); 
                    objDistributionVO.setReservedQty(objDistributionVO.getReservedQty() 
                            - objMovementItemVO.getQty());                     DistributionVO objDistributionVO1 = distributionSes 
                            .readDistribution(objMovementItemVO.getBatchId()); 3.使用连接池怎样保证每个连接会话的数据一致性的???我们每次请求数据库都可能获取的是不同的连接呀？？？？ 谢谢了。