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https://issues.apache.org/jira/browse/HBASE-15180?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15148222#comment-15148222
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Anoop Sam John edited comment on HBASE-15180 at 2/16/16 7:50 AM:
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Ya the test code change looks fine. I will fix that in the next version of 
patch.


was (Author: anoop.hbase):
Ya the test code change looks fine.

> Reduce garbage created while reading Cells from Codec Decoder
> -------------------------------------------------------------
>
>                 Key: HBASE-15180
>                 URL: https://issues.apache.org/jira/browse/HBASE-15180
>             Project: HBase
>          Issue Type: Sub-task
>          Components: regionserver
>    Affects Versions: 0.98.0
>            Reporter: Anoop Sam John
>            Assignee: Anoop Sam John
>             Fix For: 2.0.0, 1.3.0, 1.2.1
>
>         Attachments: HBASE-15180.patch, HBASE-15180_V2.patch, 
> HBASE-15180_V4.patch
>
>
> In KeyValueDecoder#parseCell (Default Codec decoder) we use 
> KeyValueUtil#iscreate to read cells from the InputStream. Here we 1st create 
> a byte[] of length 4 and read the cell length and then an array of Cell's 
> length and read in cell bytes into it and create a KV.
> Actually in server we read the reqs into a byte[] and CellScanner is created 
> on top of a ByteArrayInputStream on top of this. By default in write path, we 
> have MSLAB usage ON. So while adding Cells to memstore, we will copy the Cell 
> bytes to MSLAB memory chunks (default 2 MB size) and recreate Cells over that 
> bytes.  So there is no issue if we create Cells over the RPC read byte[] 
> directly here in Decoder.  No need for 2 byte[] creation and copy for every 
> Cell in request.
> My plan is to make a Cell aware ByteArrayInputStream which can read Cells 
> directly from it.  
> Same Codec path is used in client side also. There better we can avoid this 
> direct Cell create and continue to do the copy to smaller byte[]s path.  Plan 
> to introduce some thing like a CodecContext associated with every Codec 
> instance which can say the server/client context.



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