As noted in the SO, it's a bit confusing to me how the `checkpointing.mode`
delivery guarantees with the ones for the different sinks, and in
particular with the kafka one.
Based on the error I had, I understand that if I use `EXACTLY_ONCE` for the
checkpoints and I indicate nothing in the kafka s
I had a Flink 1.15.1 job configured with
```
execution.checkpointing.mode=`EXACTLY_ONCE`
```
that was failing with the following error
```
Sink: Committer (2/2)#732 (36640a337c6ccdc733d176b18adab979) switched from
INITIALIZING to FAILED with failure cause: java.lang.IllegalStateException:
Failed
