Re: How can I see the right format data content when I export the table content from Hbase?
Thanks for your response. Regards! Yong On Sat, Mar 17, 2012 at 10:09 PM, Stack wrote: > On Sat, Mar 17, 2012 at 1:06 AM, yonghu 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-0. I have tried 2 commands to read >> the content in the part-m-0. 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
Re: How can I see the right format data content when I export the table content from Hbase?
On Sat, Mar 17, 2012 at 1:06 AM, yonghu 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-0. I have tried 2 commands to read > the content in the part-m-0. 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