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sort示例

更新时间:2017-06-07 13:26:11   分享:   

(1)准备好测试程序jar包,假设名字为mapreduce-examples.jar;

(2)准备好sort的测试表和资源;

  • 创建表

    create table ss_in(key bigint, value bigint);
    create table ss_out(key bigint, value bigint);
    
  • 添加资源

    add jar mapreduce-examples.jar -f;
    

(3)使用tunnel导入数据;

   tunnel upload data ss_in;
  • 导入ss_in表的数据文件data内容为:
    2,1
    1,1
    3,1

测试步骤

在odpscmd中执行Sort

jar -resources mapreduce-examples.jar -classpath mapreduce-examples.jar
    com.aliyun.odps.mapred.open.example.Sort ss_in ss_out;

预期结果

作业成功结束。 输出表ss_out中内容为:

+------------+------------+
| key        | value      |
+------------+------------+
| 1          | 1          |
| 2          | 1          |
| 3          | 1          |
+------------+------------+

代码示例

    package com.aliyun.odps.mapred.open.example;

    import java.io.IOException;
    import java.util.Date;
    import com.aliyun.odps.data.Record;
    import com.aliyun.odps.data.TableInfo;
    import com.aliyun.odps.mapred.JobClient;
    import com.aliyun.odps.mapred.MapperBase;
    import com.aliyun.odps.mapred.TaskContext;
    import com.aliyun.odps.mapred.conf.JobConf;
    import com.aliyun.odps.mapred.example.lib.IdentityReducer;
    import com.aliyun.odps.mapred.utils.InputUtils;
    import com.aliyun.odps.mapred.utils.OutputUtils;
    import com.aliyun.odps.mapred.utils.SchemaUtils;

    /**
     * This is the trivial map/reduce program that does absolutely nothing other
     * than use the framework to fragment and sort the input values.
     *
     **/
    public class Sort {

      static int printUsage() {
        System.out.println("sort <input> <output>");
        return -1;
      }

      /**
       * Implements the identity function, mapping record's first two columns to
       * outputs.
       **/
      public static class IdentityMapper extends MapperBase {
        private Record key;
        private Record value;

        @Override
        public void setup(TaskContext context) throws IOException {
          key = context.createMapOutputKeyRecord();
          value = context.createMapOutputValueRecord();
        }

        @Override
        public void map(long recordNum, Record record, TaskContext context)
            throws IOException {
          key.set(new Object[] { (Long) record.get(0) });
          value.set(new Object[] { (Long) record.get(1) });
          context.write(key, value);
        }

      }

      /**
       * The main driver for sort program. Invoke this method to submit the
       * map/reduce job.
       *
       * @throws IOException
       *           When there is communication problems with the job tracker.
       **/
      public static void main(String[] args) throws Exception {

        JobConf jobConf = new JobConf();

        jobConf.setMapperClass(IdentityMapper.class);
        jobConf.setReducerClass(IdentityReducer.class);

        jobConf.setNumReduceTasks(1);

        jobConf.setMapOutputKeySchema(SchemaUtils.fromString("key:bigint"));
        jobConf.setMapOutputValueSchema(SchemaUtils.fromString("value:bigint"));

        InputUtils.addTable(TableInfo.builder().tableName(args[0]).build(), jobConf);
        OutputUtils.addTable(TableInfo.builder().tableName(args[1]).build(), jobConf);

        Date startTime = new Date();
        System.out.println("Job started: " + startTime);

        JobClient.runJob(jobConf);

        Date end_time = new Date();
        System.out.println("Job ended: " + end_time);
        System.out.println("The job took "
            + (end_time.getTime() - startTime.getTime()) / 1000 + " seconds.");
      }
    }
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