[HBASE-5255] Use singletons for OperationStatus to save memory

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.90.5, 0.92.0
• Fix Version/s: 0.92.1, 0.94.0
• Component/s: regionserver
• Labels: performance
• Hadoop Flags: Reviewed
• Assignee: Benoit Sigoure
• Reporter: Benoit Sigoure
• Created: 23/Jan/12 03:24
• Updated: 12/Oct/12 05:34
• Resolved: 24/Jan/12 04:16

Description

Every single Put causes the allocation of at least one OperationStatus, yet OperationStatus is almost always stateless, so these allocations are unnecessary and could be avoided. Attached patch adds a few singletons and uses them, with no public API change. I didn't test the patches, but you get the idea.