[HDDS-3915] Simple trash emptier on OM

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Abandoned
• Component/s: Ozone Manager
• Labels: pull-request-available
• Assignee: Siyao Meng
• Reporter: Siyao Meng
• Created: 01/Jul/20 21:21
• Updated: 05/Sep/20 18:39
• Resolved: 05/Sep/20 18:39

Description

Implementation something similar to HDFS's NameNode#startTrashEmptier in OzoneManager to enable automatic trash clean up.

Some thoughts:
1. Ozone doesn't support efficient directory renaming (not until HDDS-2939 is fully merged).

• Possible solution: Override TrashPolicyDefault by setting fs.trash.classname in core-site.xml. So we can move files under /.Trash/<timestamp_of_delete>/ instead of /.Trash/Current/ to avoid folder renaming during checkpointing.
• But this fs.trash.classname might affect ALL other FileSystems if configured in core-site.xml.
• If there a way to only apply the config to o3fs and ofs.

Update:

In the design doc, #4 is the one we are looking at. But that approach is blocked by HDDS-3620 if we need an elegant way to implement batch rename on server side.

Issue Links

• links to: GitHub Pull Request #1181