Using dump tool, we locate the missing entry is in file X. File X is the oldest rewrite log available. Use dump tool to analyze file X, it only contains AtomicGroup::Middle but no AtomicGroup::Begin.
What happened is, memtable is not aware of the atomic group that each entry/kv belongs to. After user deletes some of the entries inside an atomic group, memtable will permit the purge thread to delete the physical files that contain these entries. As a result, the Begin marker of this atomic group is deleted. Next restart this group will be broken and all entries including those not deleted by user will disappear.
Using dump tool, we locate the missing entry is in file X. File X is the oldest rewrite log available. Use dump tool to analyze file X, it only contains
AtomicGroup::Middlebut noAtomicGroup::Begin.What happened is, memtable is not aware of the atomic group that each entry/kv belongs to. After user deletes some of the entries inside an atomic group, memtable will permit the purge thread to delete the physical files that contain these entries. As a result, the
Beginmarker of this atomic group is deleted. Next restart this group will be broken and all entries including those not deleted by user will disappear.