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https://issues.apache.org/jira/browse/CASSANDRA-7882?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14140114#comment-14140114
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Benedict commented on CASSANDRA-7882:
-------------------------------------

The region size should be per memtable. Once the memtable is discarded we never 
use it again, so there should be no scaling back of size. 

> Memtable slab allocation should scale logarithmically to improve occupancy 
> rate
> -------------------------------------------------------------------------------
>
>                 Key: CASSANDRA-7882
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-7882
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>            Reporter: Jay Patel
>            Assignee: Jay Patel
>              Labels: performance
>             Fix For: 2.1.1
>
>
> CASSANDRA-5935 allows option to disable region-based allocation for on-heap 
> memtables but there is no option to disable it for off-heap memtables 
> (memtable_allocation_type: offheap_objects). 
> Disabling region-based allocation will allow us to pack more tables in the 
> schema since minimum of 1MB region won't be allocated per table. Downside can 
> be more fragmentation which should be controllable by using better allocator 
> like JEMalloc.
> How about below option in yaml?:
> memtable_allocation_type: unslabbed_offheap_objects
> Thanks.



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