[HBASE-21021] Result returned by Append operation should be ordered

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.3.0, 1.5.0
• Fix Version/s: 3.0.0-alpha-1, 1.5.0, 2.2.0
• Hadoop Flags: Reviewed
• Release Note: This change ensures Append operations are assembled into the expected order.
• Assignee: Nihal Jain
• Reporter: Nihal Jain
• Created: 07/Aug/18 14:35
• Updated: 12/Sep/18 14:21
• Resolved: 11/Sep/18 22:13

Description

Problem:

The result returned by the append operation should be ordered. Currently, it returns an unordered list, which may cause problems like if the user tries to perform Result.getValue(byte[] family, byte[] qualifier), even if the returned result has a value corresponding to (family, qualifier), the method may return null as it performs a binary search over the  unsorted result (which should have been sorted actually).

 

The result is enumerated by iterating over each entry of tempMemstore hashmap (which will never be ordered) and adding the values (see HRegion.java#L7882).

 

Actual: The returned result is unordered

Expected: Similar to increment op, the returned result should be ordered.