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

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 <[EMAIL PROTECTED]> 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

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 <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> 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
>

Please ignore the previous email which I did not describe the problem
clearly.

On Wed, Oct 31, 2012 at 3:05 PM, Vivi Lang <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> 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
>>
>
>

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 <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> 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