HBase mapreduce: write into HBase in Reducer

Question

I am learning the HBase. I know how to write a Java program using Hadoop MapReduce and write the output into HDFS; but now I want to write the same output into HBase, instead of HDFS. It should have some similar code like I did before in HDFS thing:

context.write(key,value);

Could anyone show me an example to achieve this?

Chaos Chaos · Accepted Answer · 2013-09-03T23:47:17

Here's one way to do this:

public static class MyMapper extends TableMapper<ImmutableBytesWritable, Put>  {

public void map(ImmutableBytesWritable row, Result value, Context context) throws IOException, InterruptedException {
    // this example is just copying the data from the source table...
    context.write(row, resultToPut(row,value));
}

private static Put resultToPut(ImmutableBytesWritable key, Result result) throws IOException {
    Put put = new Put(key.get());
    for (KeyValue kv : result.raw()) {
        put.add(kv);
     }
    return put;
   }
}

You can read here about Table Mapper

HBase mapreduce: write into HBase in Reducer

2 Answers