[OAK-2345] Diff reads too many nodes

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0.8, 1.1.2, 1.1.3
• Fix Version/s: 1.0.9, 1.1.4
• Component/s: core, mongomk
• Assignee: Marcel Reutegger
• Reporter: Marcel Reutegger
• Created: 11/Dec/14 13:00
• Updated: 22/Dec/14 04:10
• Resolved: 11/Dec/14 14:37

Description

DocumentNodeStore.diffManyChildren() may read too many nodes when there is an inactive cluster node with an old _lastRev on the root document. This is a regression introduced with the fix for OAK-2232.

The fix assumes an inactive cluster node does not have a revision range with an old revision seen at a current timestamp. The DocumentNodeStore will in fact purge revisions from the range in the RevisionComparator after an hour. But on startup the first background read may populate the RevisionComparator with a revision, which is potentially very old (e.g. if the clusterId is not used anymore).