Github user steveloughran commented on the issue:
https://github.com/apache/flink/pull/5521
This is very inefficient against an object store, potentially adding a few
hundred millis and $0.01 per file. I would simply catch FileNotFoundExceptions
raised in the open() call and treat them specially
See [How long does FileSystem.exists() take against
S3?](http://steveloughran.blogspot.co.uk/2016/12/how-long-does-filesystemexists-take.html)---
