flink_book/basic/checkpoint.md

# checkpoint 配置

| 配置名称 | 默认值 | 说明 |
|---|---|---|
| execution.checkpointing.interval | - | checkpoint的触发的时间，每个一段时间都会触发checkpoint。建议一般配置为1-10min左右 |
| execution.checkpointing.mode |  EXACTLY_ONCE | EXACTLY_ONCE：保证精确一次;<br> AT_LEAST_ONCE:至少一次。建议EXACTLY_ONCE |
| execution.checkpointing.timeout | 10min| checkpoint的超时时间，建议设置长一点，30min左右 |
| execution.checkpointing.unaligned.enabled |  false | 是否启用非对齐checkpoint，建议不开启 |
|  | | |



# 常见报错

## The maximum number of queued checkpoint requests exceeded 

未完成的Checkpoint排队超过了1000个。需要查看作业是否存在被压等。一般情况下作业被压会导致checkpoint失败。


## Periodic checkpoint scheduler is shut down 



## The minimum time between checkpoints is still pending 


## Not all required tasks are currently running 

部分算子任务已经完成，但是如果在维表join场景下，flink 1.13版本之前可能无法恢复checkpoint 



## An Exception occurred while triggering the checkpoint. 


## Asynchronous task checkpoint failed.


## The checkpoint was aborted due to exception of other subtasks sharing the ChannelState file 


## Checkpoint expired before completing 


## Checkpoint has been subsumed


## Checkpoint was declined


## Checkpoint was declined (tasks not ready) 


## Checkpoint was declined (task is closing) 


## Checkpoint was canceled because a barrier from newer checkpoint was received


## Task received cancellation from one of its inputs 


## Checkpoint was declined because one input stream is finished 


## CheckpointCoordinator shutdown 


## Checkpoint Coordinator is suspending 


## FailoverRegion is restarting 


## Task has failed 


## Task local checkpoint failure 


## Unknown task for the checkpoint to notify 


## Failure to finalize checkpoint 


## Trigger checkpoint failure