[OAK-4279] Rework offline compaction

• Type: Task
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 1.5.3, Segment Tar 0.0.2, 1.6.0
• Component/s: segment-tar
• Labels: compaction gc
• Epic Link: Segment Tar
• Assignee: Alex Deparvu
• Reporter: Michael Dürig
• Created: 22/Apr/16 14:57
• Updated: 20/Jun/16 07:59
• Resolved: 03/Jun/16 08:45

Description

The fix for OAK-3348 broke some of the previous functionality of offline compaction:

• No more progress logging
• Compaction is not interruptible any more (in the sense of OAK-3290)
• Offline compaction could remove the ids of the segment node states to squeeze out some extra space. Those are only needed for later generations generated via online compaction.

We should probably implement offline compaction again through a dedicated Compactor class as it was done in oak-segment instead of relying on the de-duplication cache (aka online compaction).

Issue Links

• blocks: OAK-4247 Deprecate oak-segment
• is related to: OAK-4478 Enable writer cache for offline compaction
• is related to: OAK-3348 Cross gc sessions might introduce references to pre-compacted segments