[HDDS-2112] Ozone rename is behaving different compared with HDFS

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Component/s: Ozone Filesystem
• Assignee: Unassigned
• Reporter: István Fajth
• Created: 11/Sep/19 16:33
• Updated: 27/Jul/20 18:48
• Resolved: 11/Sep/19 20:03

Description

I am attaching a patch file, that introduces two new tests for the OzoneFileSystem implementation which demonstrates the expected behaviour.

Case 1:
Given a directory a file "/source/subdir/file", and a directory /target
When fs.rename("/source/subdir/file", "/target/subdir/file") is called
Then DistributedFileSystem (HDFS), is returning false from the method, while OzoneFileSystem throws a FileNotFoundException as "/target/subdir" is not existing.

The expected behaviour would be to return false in this case instead of throwing an exception with that behave the same as DistributedFileSystem does.

 

Case 2:
Given a directory "/source" and a file "/targetFile"
When fs.rename("/source", "/targetFile") is called
Then DistributedFileSystem (HDFS), is returning false from the method, while OzoneFileSystem throws a FileAlreadyExistsException as "/targetFile" does exist.

The expected behaviour would be to return false in this case instead of throwing an exception with that behave the same as DistributedFileSystem does.

 

It may be considered as well a bug in HDFS, however it is not clear from the FileSystem interface's documentation on the two rename methods that it defines in which cases an exception should be thrown and in which cases a return false is the expected behaviour.

Issue Links

• is related to: HADOOP-17157 S3A rename operation not the same as HDFS when dest is empty dir