[HBASE-21921] Notify users if the ByteBufAllocator is always allocating ByteBuffers from heap which means the increacing GC pressure

• Type: Sub-task
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 3.0.0-alpha-1, 2.3.0
• Hadoop Flags: Reviewed
• Assignee: Zheng Hu
• Reporter: Zheng Hu
• Created: 18/Feb/19 07:10
• Updated: 01/Jul/22 21:44
• Resolved: 07/May/19 10:26

Description

As the javadoc of ByteBuffAllocator says:

There's possible that the desired memory size is large than ByteBufferPool has, we'll downgrade to allocate ByteBuffers from heap which meaning the GC pressure may increase again. Of course, an better way is increasing the ByteBufferPool size if we detected this case. 

So I think we need some messages to remind the user that an larger ByteBufferPool size may be better if the allocator allocate ByteBuffer from heap frequently.

Issue Links

• links to: Review board