[HIVE-17963] Fix for HIVE-17113 can be improved for non-blobstore filesystems

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0
• Assignee: Jason Dere
• Reporter: Jason Dere
• Created: 02/Nov/17 02:04
• Updated: 22/May/18 23:13
• Resolved: 07/Nov/17 18:20

Description

HIVE-17113/HIVE-17813 fix the duplicate file issue by performing file moves on a file-by-file basis. For non-blobstore filesystems this results in many more filesystem/namenode operations compared to the previous Utilities.mvFileToFinalPath() behavior (dedup files in src dir, rename src dir to final dir).
For non-blobstore filesystems, a better solution would be the one described here:

1) Move the temp directory to a new directory name, to prevent additional files from being added by any runaway processes.
2) Run removeTempOrDuplicateFiles() on this renamed temp directory
3) Run renameOrMoveFiles() to move the renamed temp directory to the final location.

This results in only one additional file operation in non-blobstore FSes compared to the original Utilities.mvFileToFinalPath() behavior.

The proposal is to do away with the config setting hive.exec.move.files.from.source.dir and always have behavior that should take care of the duplicate file issue described in HIVE-17113. For non-blobstore filesystems we will do steps 1-3 described above. For blobstore filesystems we will do the solution done in HIVE-17113/HIVE-17813 which does the file-by-file copy - this should have the same number of file operations as doing a rename directory on blobstore, which effectively results in file moves on a file-by-file basis.

Issue Links

• is related to: HIVE-17113 Duplicate bucket files can get written to table by runaway task
• links to: https://reviews.apache.org/r/63544/