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https://issues.apache.org/jira/browse/HBASE-18097?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16029219#comment-16029219
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Duo Zhang commented on HBASE-18097:
-----------------------------------

We can not change the definition in proto file, but I think we can try to find 
a way to only put a single value to the list, as you said, to save some data in 
the rpc response.

I'm currently on vacation. Will be back next week. Will take a deep look at 
that time.

Thanks.

> Client can save 1 RPC call for CloseScannerRequest
> --------------------------------------------------
>
>                 Key: HBASE-18097
>                 URL: https://issues.apache.org/jira/browse/HBASE-18097
>             Project: HBase
>          Issue Type: Improvement
>            Reporter: Karan Mehta
>
> Starting version 1.3, HBase automatically closes scanner on server side 
> whenever the results are exhausted and corresponding bits are set in the 
> {{ScanResponse}} proto returned to the client. We can use that info to 
> eliminate the closeScanRequest RPC call, thereby saving 1 RPC per region per 
> scan. This can be particularly useful for tables with more regions.
> Also, currently the {{ScanResponse}} proto sends out 1 bit per {{Result}} 
> that it has embeds inside the {{CellScanner}} to indicate if it is partial or 
> not. 
> {code}
>     // In every RPC response there should be at most a single partial result. 
> Furthermore, if
>     // there is a partial result, it is guaranteed to be in the last position 
> of the array.
> {code}
> According to client, only the last result can be partial, thus this repeated 
> bool can be converted to a bool, thus reducing overhead of serialization and 
> deserialization of the array. This will break wire compatibility therefore 
> this is something to look for in upcoming versions.



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