我和Cassandra合作的经验不多，如果我的方法不对，请原谅。
我正在尝试用map reduce在cassandra进行批量加载
基本上是字数计算的例子
参考文献：http://henning.kropponline.de/2012/11/15/using-cassandra-hadoopbulkoutputformat/
我已经把简单的hadoop wordcountMap器的例子，并稍微修改了驱动程序代码和减速机根据上述例子。
我也成功地生成了输出文件。现在我的疑问是如何执行Cassandra部分加载？我的方法有什么不同吗？
请给我建议。
这是驱动程序代码的一部分

Job job = new Job();
 job.setJobName(getClass().getName());
 job.setJarByClass(CassaWordCountJob.class);

 Configuration conf = job.getConfiguration();
 conf.set("cassandra.output.keyspace", "test");
 conf.set("cassandra.output.columnfamily", "words");
 conf.set("cassandra.output.partitioner.class", "org.apache.cassandra.dht.RandomPartitioner");
 conf.set("cassandra.output.thrift.port","9160");    // default
 conf.set("cassandra.output.thrift.address", "localhost");
 conf.set("mapreduce.output.bulkoutputformat.streamthrottlembits", "400");

 job.setMapperClass(CassaWordCountMapper.class);
 job.setMapOutputKeyClass(Text.class);
 job.setMapOutputValueClass(IntWritable.class);
 FileInputFormat.setInputPaths(job, new Path(args[0]));
 job.setReducerClass(CassaWordCountReducer.class);
 FileOutputFormat.setOutputPath(job, new Path("/home/user/Desktop/test/cassandra")); 
 MultipleOutputs.addNamedOutput(job, "reducer", BulkOutputFormat.class, ByteBuffer.class, List.class);
 return job.waitForCompletion(true) ? 0 : 1;

Map器与普通的wordcountMap器相同，它只是标记并发出word，1
reducer类的形式如下

public class CassaWordCountReducer extends 
        Reducer<Text, IntWritable, ByteBuffer, List<Mutation>> {

    @Override
    public void reduce(Text key, Iterable<IntWritable> values, Context context)
            throws IOException, InterruptedException {
        List<Mutation> columnsToAdd = new ArrayList<Mutation>();
        Integer wordCount = 0;
        for(IntWritable value : values) {
            wordCount += value.get();
        }
        Column countCol = new Column(ByteBuffer.wrap("count".getBytes()));
        countCol.setValue(ByteBuffer.wrap(wordCount.toString().getBytes()));
        countCol.setTimestamp(new Date().getTime());
        ColumnOrSuperColumn wordCosc = new ColumnOrSuperColumn();
        wordCosc.setColumn(countCol);
        Mutation countMut = new Mutation();
        countMut.column_or_supercolumn = wordCosc;
        columnsToAdd.add(countMut);
        context.write(ByteBuffer.wrap(key.toString().getBytes()), columnsToAdd);
    }
}