Hi,
I have a job (with Flink 1.6.4) which uses rocksdb incremental checkpointing, but the checkpointing always fails with `IllegalStateException`,
because hen performing `RocksDBIncrementalSnapshotOperation`, rocksdb finds that `localBackupDirectory`, which should be created earlier
by rocksdb checkpoint, doesn’t exist. But there is no error message about failures of rocksdb checkpoint.
What could possibly be the cause? Thanks a lot!