I'm experiencing quite weird behavior working with Confluent JDBC connector. I'm pretty sure that it's not related to Confluent stack, but to Kafka-connect framework itself.

So, I define `offset.storage.file.filename` property as default `/tmp/connect.offsets` and run my sink connector. Obviously, I expect connector to persist offsets in the given file (it doesn't exist on file system, but it should be automatically created, right?). Documentation says:

> 
> `offset.storage.file.filename`
>  The file to store connector offsets in. By storing offsets on disk, a standalone process can be stopped and started on a single node and resume where it previously left off.
> 
> 
> 

But Kafka behaves in completely different manner.

1. It checks if the given file exists.
2. It it's not, Kafka just ignores it and persists offsets in Kafka topic.
3. If I create given file manually, reading fails anyway (EOFException) and offsets are being persisted in topic again.

Is it a bug or, more likely, I don't understand how to work with this configurations? I understand difference between two approaches to persist offsets and file storage is more convenient for my needs.