Hello,

I have used the command ./hbase
org.apache.hadoop.hbase.mapreduce.Export 'test'
http://localhost:8020/test to export the data content from the test
table. And I can see the exported content from my hdfs folder,
hdfs://localhost/test/part-m-00000. I have tried 2 commands to read
the content in the part-m-00000. One is -cat, the other is -text. But
both of them show me some garbled message. Can anyone tell me that how
to rightly read the content from the exported file?

Thanks!

Yong

On Sat, Mar 17, 2012 at 1:06 AM, yonghu <[EMAIL PROTECTED]> wrote:
> Hello,
>
> I have used the command ./hbase
> org.apache.hadoop.hbase.mapreduce.Export 'test'
> http://localhost:8020/test to export the data content from the test
> table. And I can see the exported content from my hdfs folder,
> hdfs://localhost/test/part-m-00000. I have tried 2 commands to read
> the content in the part-m-00000. One is -cat, the other is -text. But
> both of them show me some garbled message. Can anyone tell me that how
> to rightly read the content from the exported file?
>

The export produces hadoop sequencefiles where the key is a the row is
a serialized instance of ImmutableBytesWritable and the value a
serialized instance of the hbase Result object.  See
http://hbase.apache.org/xref/org/apache/hadoop/hbase/mapreduce/Export.html#99
where the mapreduce job is set up.

To read the content, you need one of these:
http://hadoop.apache.org/common/docs/current/api/org/apache/hadoop/io/SequenceFile.Reader.html
 Study the SequenceFileInputFormat for sample code.

St.Ack

Thanks for your response.

Regards!

Yong

On Sat, Mar 17, 2012 at 10:09 PM, Stack <[EMAIL PROTECTED]> wrote:
> On Sat, Mar 17, 2012 at 1:06 AM, yonghu <[EMAIL PROTECTED]> wrote:
>> Hello,
>>
>> I have used the command ./hbase
>> org.apache.hadoop.hbase.mapreduce.Export 'test'
>> http://localhost:8020/test to export the data content from the test
>> table. And I can see the exported content from my hdfs folder,
>> hdfs://localhost/test/part-m-00000. I have tried 2 commands to read
>> the content in the part-m-00000. One is -cat, the other is -text. But
>> both of them show me some garbled message. Can anyone tell me that how
>> to rightly read the content from the exported file?
>>
>
> The export produces hadoop sequencefiles where the key is a the row is
> a serialized instance of ImmutableBytesWritable and the value a
> serialized instance of the hbase Result object.  See
> http://hbase.apache.org/xref/org/apache/hadoop/hbase/mapreduce/Export.html#99
> where the mapreduce job is set up.
>
> To read the content, you need one of these:
> http://hadoop.apache.org/common/docs/current/api/org/apache/hadoop/io/SequenceFile.Reader.html
>  Study the SequenceFileInputFormat for sample code.
>
> St.Ack