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From Eli Collins <...@cloudera.com>
Subject Re: Why dataOut is FileOutputStream?
Date Sat, 06 Nov 2010 03:36:42 GMT
Hey Thanh,

Data gets written in 64KB packets so there doesn't seem to be a need
to buffer it.

Thanks,
Eli

On Thu, Nov 4, 2010 at 2:58 PM, Thanh Do <thanhdo@cs.wisc.edu> wrote:
> Hi all,
>
> When a datanode receive a block, the datanode
> write the block into 2 streams on disk:
> - the data stream (dataOut)
> - the checksum stream (checksumOut)
>
> While the checksumOut is created with following code:
>   this.checksumOut = new DataOutputStream(new BufferedOutputStream(
>                                          streams.checksumOut,
>                                          SMALL_BUFFER_SIZE));
> The dataOut is simply FileOutputStream()
>
> So, the checksumOut is buffered, but dataOut is not.
>
> Is there any particular reason for doing so?
> or it doesn't matter, because after that, we flush
> the two streams anyway?
>
> Thanks
> Thanh
>

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