[HBASE-21957] Unify refCount of BucketEntry and refCount of hbase.nio.ByteBuff into one

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0-alpha-1, 2.3.0
• Hadoop Flags: Reviewed
• Assignee: Zheng Hu
• Reporter: Zheng Hu
• Created: 26/Feb/19 07:52
• Updated: 01/Jul/22 21:44
• Resolved: 22/Apr/19 08:00

Description

After HBASE-12295, we have block with MemoryType.SHARED or MemoryType.EXCLUSIVE, the block in offheap BucketCache will be shared, and have an reference count to track its life cycle. If no rpc reference to the shared block, then the block can be evicted.

while after the HBASE-21916, we introduced an refcount for ByteBuff, then I think we can unify the two into one. tried to fix this when preparing patch for HBASE-21879, but seems can be different sub-task, and it won't affect the main logic of HBASE-21879, so create a seperate one.

Issue Links

• relates to: HBASE-12295 Prevent block eviction under us if reads are in progress from the BBs
• links to: Design Document
• links to: Review board