[OAK-4127] Cleanup creates new generation of tar file without removing any segments

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Not A Problem
• Fix Version/s: Segment Tar 0.0.2, 1.6.0
• Component/s: segment-tar
• Labels: cleanup gc
• Epic Link: SegmentMK revision GC
• Assignee: Unassigned
• Reporter: Michael Dürig
• Created: 15/Mar/16 20:14
• Updated: 27/Jun/16 08:21
• Resolved: 07/Jun/16 21:47

Description

On some deployments I have seen tar files with a quite hight generation post-fix (e.g. 'v'). From the log files I could deduce that this particular tar file was rewritten multiple times without actually any segment being removed.

I assume this is caused by the 25% gain threshold not taking the sizes contributed by the index and the graph entries into account.

We should try to come up with a test case validating above hypothesis. A fix should then be relatively straight forward: either include the sizes of these two entries in the calculation or skip further clean cycles if a file size drops below a certain size.

Issue Links

• is related to: OAK-4147 TarReader#loadGraph wrongly detects segment graph as corrupt
• is related to: OAK-4253 CLONE - TarReader#loadGraph wrongly detects segment graph as corrupt