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From Subroto <ssan...@datameer.com>
Subject Re: TableRecordReaderImpl is not able to get the rows
Date Thu, 14 Jun 2012 08:05:35 GMT
Hi Sonal,

Thanks for your suggestion… I checked my code and found out that I was doing something like
this:
for (String column : columns) { 
	scan.addColumn(Bytes.toBytes(column), Bytes.toBytes(""))
}

The same scan object was being set in the configuration. After removing this piece of code,
the MR Job worked fine.

One more doubt:
Scan.addColumn takes two argument:
public Scan addColumn(byte[] family,
                      byte[] qualifier)
The first one is the column name in bytes. What should be passed as second argument if I want
the qualifier to be ignored(I mean to include any qualifier)???
My HBase table looks like this:
ROW                                                                  COLUMN+CELL         
                                                                                         
                                                                                         

 row1                                                                column=cf:a, timestamp=1339581548508,
value=value1                                                                             
                                                                         
 row2                                                                column=cf:b, timestamp=1339581557585,
value=value2                                                                             
                                                                         
 row3                                                                column=cf:c, timestamp=1339581566227,
value=value3   

Thanks again for the correct pointers…. :-)

Cheers,
Subroto Sanyal
On Jun 14, 2012, at 9:07 AM, Sonal Goyal wrote:

> Are you doing something specific with the RecordReader? Maybe you can post
> more of your code as it is difficult to tell anything right now.
> 
> Best Regards,
> Sonal
> Crux: Reporting for HBase <https://github.com/sonalgoyal/crux>
> Nube Technologies <http://www.nubetech.co>
> 
> <http://in.linkedin.com/in/sonalgoyal>
> 
> 
> 
> 
> 
> On Wed, Jun 13, 2012 at 7:28 PM, Subroto <ssanyal@datameer.com> wrote:
> 
>> Hi Sonal,
>> 
>> The Scan is being created by:
>> void
>> org.apache.hadoop.hbase.mapreduce.TableInputFormat.setConf(Configuration
>> configuration)
>> I am not providing any other scan options…. :-(
>> 
>> Cheers,
>> Subroto Sanyal
>> 
>> On Jun 13, 2012, at 1:30 PM, Sonal Goyal wrote:
>> 
>>> Hi Subroto,
>>> 
>>> How are you configuring your job? Are you providing any Scan options?
>> Check
>>> Chapter 7 of the ref guide at
>>> 
>>> http://hbase.apache.org/book/mapreduce.example.html
>>> 
>>> Best Regards,
>>> Sonal
>>> Crux: Reporting for HBase <https://github.com/sonalgoyal/crux>
>>> Nube Technologies <http://www.nubetech.co>
>>> 
>>> <http://in.linkedin.com/in/sonalgoyal>
>>> 
>>> 
>>> 
>>> 
>>> 
>>> On Wed, Jun 13, 2012 at 4:47 PM, Subroto <ssanyal@datameer.com> wrote:
>>> 
>>>> Hi,
>>>> 
>>>> I have a table with details:
>>>> hbase(main):024:0> scan 'test'
>>>> ROW
>>>> COLUMN+CELL
>>>> row1
>>>> column=cf:a, timestamp=1339581548508, value=value1
>>>> row2
>>>> column=cf:b, timestamp=1339581557585, value=value2
>>>> row3
>>>> column=cf:c, timestamp=1339581566227, value=value3
>>>> 3 row(s) in 0.0200 seconds
>>>> 
>>>> When my MR job tries to access TableRecordReader
>>>> org.apache.hadoop.hbase.client.HTable.ClientScanner.nextScanner set the
>>>> "value" to null for every call which gives a sense to my MR application
>>>> that there are no records in the table.
>>>> 
>>>> I am using: 0.92.1 HBase and 0.23.1 Hadoop…..
>>>> 
>>>> What can be the possible reason(s) behind it??
>>>> 
>>>> Cheers,
>>>> Subroto Sanyal
>> 
>> 


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