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https://issues.apache.org/jira/browse/HBASE-17644?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15865150#comment-15865150
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ramkrishna.s.vasudevan commented on HBASE-17644:
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bq.That there is a mix of types makes a difference? Or is it just that we
always do millions of comparisons and offheap comparisons are slower?
Our tests with PE shows that it is the mix that creates differences. Offheap
ByteBuffered based comparisons are infact faster.
But am trying to prove this with JMH but am not getting the same convincing
result. But PE results are clear.
> Create ByteBuffered cells only while creating a cell from MSLAB
> ---------------------------------------------------------------
>
> Key: HBASE-17644
> URL: https://issues.apache.org/jira/browse/HBASE-17644
> Project: HBase
> Issue Type: Sub-task
> Components: regionserver
> Affects Versions: 2.0.0
> Reporter: ramkrishna.s.vasudevan
> Fix For: 2.0.0
>
>
> We create a cell out of the Bytebuffer that is returned by MSLAB. This BB can
> be offheap or onheap type. If MSLAB is full we return onheap byte buffer. So
> the place where we create a cell by copying data to this buffer we either
> create KeyValue or OffheapKV based on the buffer type. So what we saw in
> tests is that since we have a combination of Cells the comparisons that
> happens when adding to memstore happens millions of times and that has an
> impact on the performance of write path. In read path this is not significant
> enougth (though we have plans to just create one type of cells every where in
> Server side).
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