Stale cluster ids can potentially lead to lots of previous docs traversal in NodeDocument.getNewestRevision

When some (actual test case and conditions still being investigated) of the following conditions are met:

• There are property value changes from different cluster id
• There are very old and stale cluster id (probably older incarnations of current node itself)
• A parallel background split removes all _commitRoot, _revision entries such that the latest one (which is less that baseRev) is very old

, finding newest revision traverses a lot of previous docs. Since root document gets split a lot and is a very common commitRoot (thus participating during checkConflicts in lot of commits), the issue can slow down commits by a lot