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From Harsh J <ha...@cloudera.com>
Subject Re: A question about reading one block
Date Thu, 01 Nov 2012 03:18:29 GMT
Vivi,

There is no inbuilt function to do this, no. You'd have to write the
utility yourself.

On Thu, Nov 1, 2012 at 3:01 AM, Vivi Lang <sqlxweiwei@gmail.com> wrote:
> Please ignore the previous email which I did not describe the problem
> clearly.
>
> On Wed, Oct 31, 2012 at 3:05 PM, Vivi Lang <sqlxweiwei@gmail.com> wrote:
>
>> Hi, thks for the replying.
>>
>> Is there any function can help me to create a InputStream for a certain
>> Block which stored in a certain datanode
>> Thanks,
>>
>> On Sat, Oct 27, 2012 at 9:41 PM, Harsh J <harsh@cloudera.com> wrote:
>>
>>> Vivi,
>>>
>>> Assuming you know how to get the block info out of a file's metadata,
>>> opening a file for read (with FileSystem.open API, etc.) with an
>>> offset and length set to to match that of a block, will open and read
>>> only that block.
>>>
>>> On Sat, Oct 27, 2012 at 2:19 AM, Vivi Lang <sqlxweiwei@gmail.com> wrote:
>>> > Hi guys,
>>> >
>>> > I am writing a program which need the data of several specific blocks (I
>>> > know the blockinfo of those blocks), if I use the Hadoop 0.20, is there
>>> > any  funtion which can help me to retrieve the content of block?
>>> >
>>> > Thanks,
>>> > Vivi
>>>
>>>
>>>
>>> --
>>> Harsh J
>>>
>>
>>



-- 
Harsh J

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