Re: How to convert start_token,end_token to real key value?

[Narendra Sharma <na...@gmail.com>]

A token is a MD5 hash (one way hash). You cannot compute the key given a
token. You can however compute MD5 hash of your keys and compare them with
tokens.

-Naren

On Sat, Dec 31, 2011 at 2:07 PM, ravikumar visweswara <talk2hadoop@gmail.com
> wrote:

> Hello All,
>
> I have requirement to copy data from cassandra to hadoop from/to a
> specific key. This is supported in 1.0.0.  But I am using cassandra version
> 0.7.1 and hadoop version 20.2.
>
> In my mapreduce job(InputFormat class) i have an object of TokenRange. I
> need to filter certain ranges based on some exclusion rules.
> i have readable key range to include. Could some one help me on how to
> convert start_token and end_token to readable format and compare with my
> input keys (range)?
>
> I know that 1.0.0 have better capabilities to specify keyRanges in hadoop
> mapreduce. But for now, i will have to work with 0.7.1
>
> Thanks and Regards
> Ravi
>
>
>


-- 
Narendra Sharma
Software Engineer
*http://www.aeris.com <http://www.persistentsys.com>*
*http://narendrasharma.blogspot.com/*

Re: How to convert start_token,end_token to real key value?

[Philippe <wa...@gmail.com>]

No
Le 2 janv. 2012 08:44, "ravikumar visweswara" <ta...@gmail.com> a
écrit :

> Thank You Naren. If key k1>k2 (lexicologicaly), will md5(k1) > md5(k2)?.
>
> - R
>
>
> On Sun, Jan 1, 2012 at 7:07 PM, Narendra Sharma <narendra.sharma@gmail.com
> > wrote:
>
>> A token is a MD5 hash (one way hash). You cannot compute the key given a
>> token. You can however compute MD5 hash of your keys and compare them with
>> tokens.
>>
>> -Naren
>>
>>
>> On Sat, Dec 31, 2011 at 2:07 PM, ravikumar visweswara <
>> talk2hadoop@gmail.com> wrote:
>>
>>> Hello All,
>>>
>>> I have requirement to copy data from cassandra to hadoop from/to a
>>> specific key. This is supported in 1.0.0.  But I am using cassandra version
>>> 0.7.1 and hadoop version 20.2.
>>>
>>> In my mapreduce job(InputFormat class) i have an object of TokenRange. I
>>> need to filter certain ranges based on some exclusion rules.
>>> i have readable key range to include. Could some one help me on how to
>>> convert start_token and end_token to readable format and compare with my
>>> input keys (range)?
>>>
>>> I know that 1.0.0 have better capabilities to specify keyRanges in
>>> hadoop mapreduce. But for now, i will have to work with 0.7.1
>>>
>>> Thanks and Regards
>>> Ravi
>>>
>>>
>>>
>>
>>
>> --
>> Narendra Sharma
>> Software Engineer
>> *http://www.aeris.com <http://www.persistentsys.com>*
>> *http://narendrasharma.blogspot.com/*
>>
>>
>>
>

Re: How to convert start_token,end_token to real key value?

[ravikumar visweswara <ta...@gmail.com>]

Thank You Naren. If key k1>k2 (lexicologicaly), will md5(k1) > md5(k2)?.

- R


On Sun, Jan 1, 2012 at 7:07 PM, Narendra Sharma
<na...@gmail.com>wrote:

> A token is a MD5 hash (one way hash). You cannot compute the key given a
> token. You can however compute MD5 hash of your keys and compare them with
> tokens.
>
> -Naren
>
>
> On Sat, Dec 31, 2011 at 2:07 PM, ravikumar visweswara <
> talk2hadoop@gmail.com> wrote:
>
>> Hello All,
>>
>> I have requirement to copy data from cassandra to hadoop from/to a
>> specific key. This is supported in 1.0.0.  But I am using cassandra version
>> 0.7.1 and hadoop version 20.2.
>>
>> In my mapreduce job(InputFormat class) i have an object of TokenRange. I
>> need to filter certain ranges based on some exclusion rules.
>> i have readable key range to include. Could some one help me on how to
>> convert start_token and end_token to readable format and compare with my
>> input keys (range)?
>>
>> I know that 1.0.0 have better capabilities to specify keyRanges in hadoop
>> mapreduce. But for now, i will have to work with 0.7.1
>>
>> Thanks and Regards
>> Ravi
>>
>>
>>
>
>
> --
> Narendra Sharma
> Software Engineer
> *http://www.aeris.com <http://www.persistentsys.com>*
> *http://narendrasharma.blogspot.com/*
>
>
>