关于flink 写于kafka时的transactionId 生成问题

hi，在写入kafka的时候自动生成了一个transactionId，请问这个id生成的方式是什么，我自己指定好像并不起作用。 作业我已经停止了，但是看kafka的日志还是不断的在刷Initialized transactionalId………. ，而且该程序再此启动就会报： Caused by: org.apache.kafka.common.errors.ProducerFencedException: Producer attempted an operation with an old epoch. Either there is a newer producer with the same transactionalId, or the producer's transaction has been expired by the broker. 错误，请问有什么办法可以避免这个问题？ 下面是kafka的日志，一直在刷，很多都是好几天之前的任务了

2019-08-29 17:08:48,911] INFO [TransactionCoordinator id=0] Initialized transactionalId Split Reader: Custom File Source -> (Sink: Print to Std. Out, Sink: Unnamed)-7b96fd3ac98d0efc878b17e02839b3d6-3 with producerId 1011 and producer epoch 14255 on partition __transaction_state-36 (kafka.coordinator.transaction.TransactionCoordinator) [2019-08-29 17:08:49,244] INFO [TransactionCoordinator id=0] Initialized transactionalId Split Reader: Custom File Source -> (Sink: Print to Std. Out, Sink: Unnamed)-7b96fd3ac98d0efc878b17e02839b3d6-4 with producerId 1012 and producer epoch 16544 on partition __transaction_state-35 (kafka.coordinator.transaction.TransactionCoordinator) [2019-08-29 17:08:49,518] INFO [TransactionCoordinator id=0] Initialized transactionalId Split Reader: Custom File Source -> (Sink: Print to Std. Out, Sink: Unnamed)-7b96fd3ac98d0efc878b17e02839b3d6-1 with producerId 1013 and producer epoch 15460 on partition __transaction_state-38 (kafka.coordinator.transaction.TransactionCoordinator) [2019-08-29 17:08:49,786] INFO [TransactionCoordinator id=0] Initialized transactionalId Split Reader: Custom File Source -> (Sink: Print to Std. Out, Sink: Unnamed)-7b96fd3ac98d0efc878b17e02839b3d6-2 with producerId 1014 and producer epoch 7781 on partition __transaction_state-37 (kafka.coordinator.transaction.TransactionCoordinator) [2019-08-29 17:08:50,054] INFO [TransactionCoordinator id=0] Initialized transactionalId Split Reader: Custom File Source -> (Sink: Print to Std. Out, Sink: Unnamed)-7b96fd3ac98d0efc878b17e02839b3d6-0 with producerId 1015 and producer epoch 7529 on partition __transaction_state-39 (kafka.coordinator.transaction.TransactionCoordinator) [2019-08-29 17:08:50,310] INFO [TransactionCoordinator id=0] Initialized transactionalId Split Reader: Custom File Source -> (Sink: Print to Std. Out, Sink: Unnamed)-7b96fd3ac98d0efc878b17e02839b3d6-3 with producerId 1011 and producer epoch 14256 on partition __transaction_state-36 (kafka.coordinator.transaction.TransactionCoordinator) [2019-08-29 17:08:51,078] INFO [TransactionCoordinator id=0] Initialized transactionalId Split Reader: Custom File Source -> (Sink: Print to Std. Out, Sink: Unnamed)-7b96fd3ac98d0efc878b17e02839b3d6-4 with producerId 1012 and producer epoch 16545 on partition __transaction_state-35 (kafka.coordinator.transaction.TransactionCoordinator) [2019-08-29 17:08:53,047] INFO [TransactionCoordinator id=0] Initialized transactionalId Split Reader: Custom File Source -> (Sink: Print to Std. Out, Sink: Unnamed)-7b96fd3ac98d0efc878b17e02839b3d6-1 with producerId 1013 and producer epoch 15461 on partition __transaction_state-38 (kafka.coordinator.transaction.TransactionCoordinator) *来自志愿者整理的flink邮件归档