We’ve integrated Box with Apache NiFi, there is a processor which puts files to Box folders. In case a folder does not exist, it is created by NiFi. Usually there are several nodes in NiFi cluster so two or more NiFi instances try to create the same folder in Box parallel.

Normally Box returns 409 (conflict) in case the folder is being created while another request arrives for the creation of the same folder.

We experienced intermittent failures during our system tests when subfolders are created in Box (e.g. folder1/folder2/folder3) .
Sometimes a folder is created twice with the same name, which is considered illegal since folder names are unique in Box.
It seems Box does not throw an error in some cases and creates a folder with an existing name.
According to Box developers this is not the expected behaviour. 

We use box-java-sdk, 4.4.0.