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https://issues.apache.org/jira/browse/CASSANDRA-4297?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13286271#comment-13286271
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Jonathan Ellis commented on CASSANDRA-4297:
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bq. Most of the time was spent on source node waiting for dest node to 
decompress and write to disk

It looks like the only reason to decompress is to compare crc32...  is that 
right?  Why did we crc uncompressed data instead of compressed?  Should we 
introduce a new version of snappy compression that CRCs the compressed data 
instead?
                
> Use java NIO as much as possible when streaming compressed SSTables
> -------------------------------------------------------------------
>
>                 Key: CASSANDRA-4297
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-4297
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Yuki Morishita
>            Assignee: Yuki Morishita
>            Priority: Minor
>              Labels: streaming
>             Fix For: 1.2
>
>
> Back in 0.8, streaming uses java NIO (FileChannel#transferTo/transferFrom) to 
> perform zero copy file transfer between nodes. Since 1.0, in order to add new 
> features like sstable compression and internode encryption we had to switch 
> to java IO Input/OutputStreams. What we currently do to transfer compressed 
> SSTable is, in source node, 1) decompress chunk in SSTable, 2) compress using 
> LZF for network, and in destination node, 3) decompress using LZF as reading 
> from socket, 4) compress for SSTable on disk.
> Now, 1.1 comes out with SSTable compression turned on by default. It is 
> reasonable to transfer compressed file as is using NIO instead of 
> decompress/compress in source node.

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