[OAK-2045] Long running JCR session prevent live cleanup in Segment FileStore

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Component/s: segmentmk
• Labels: gc
• Epic Link: SegmentMK revision GC
• Assignee: Michael Dürig
• Reporter: Chetan Mehrotra
• Created: 21/Aug/14 12:32
• Updated: 08/Oct/19 15:21
• Resolved: 09/Jun/15 08:30

Description

Cleanup operation in SegmentNodeStore detects the un referenced garbage and clean it up. To determine the reference validity it starts with an initial set of SegmentId which have a live java reference.

This works fine for simple setup but when Oak repository is used in an application (like Sling) where application code can create long running session (for observation) then such session are bound to old NodeState at time of startup. Such references prevent the cleanup logic to remove older revisions while system is running. Such revisions can only be removed via an offline compaction-> cleanup.

Need to find out a way where we can migrate such old NodeState references to newer revisions

Issue Links

• depends upon: OAK-2192 Concurrent commit during compaction results in mixed segments
• is related to: OAK-2124 Trigger compaction after restart to workaround issue due to long running JCR session
• relates to: OAK-2384 SegmentNotFoundException when keeping JCR Value references
• relates to: OAK-2140 Segment Compactor will not compact binaries > 16k
• relates to: OAK-2192 Concurrent commit during compaction results in mixed segments
• relates to: OAK-2408 Investigate ways to make revision gc more precise