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Sort示例

更新时间:2017-10-17 14:18:57

测试准备

  1. 准备好测试程序的 Jar 包,假设名字为 mapreduce-examples.jar,本地存放路径为 data\resources。

  2. 准备好 Sort 的测试表和资源。

    • 创建测试表。

      1. create table ss_in(key bigint, value bigint);
      2. create table ss_out(key bigint, value bigint);
    • 添加测试资源。

      1. add jar data\resources\mapreduce-examples.jar -f;
  3. 使用 tunnel 导入数据。

    1. tunnel upload data ss_in;

    导入 ss_in 表的数据文件 data 的内容,如下所示:

    1. 2,1
    2. 1,1
    3. 3,1

测试步骤

在 odpscmd 中执行 Sort,如下所示:

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

预期结果

作业成功结束后,输出表 ss_out 中的内容,如下所示:

  1. +------------+------------+
  2. | key | value |
  3. +------------+------------+
  4. | 1 | 1 |
  5. | 2 | 1 |
  6. | 3 | 1 |
  7. +------------+------------+

代码示例

  1. package com.aliyun.odps.mapred.open.example;
  2. import java.io.IOException;
  3. import java.util.Date;
  4. import com.aliyun.odps.data.Record;
  5. import com.aliyun.odps.data.TableInfo;
  6. import com.aliyun.odps.mapred.JobClient;
  7. import com.aliyun.odps.mapred.MapperBase;
  8. import com.aliyun.odps.mapred.TaskContext;
  9. import com.aliyun.odps.mapred.conf.JobConf;
  10. import com.aliyun.odps.mapred.example.lib.IdentityReducer;
  11. import com.aliyun.odps.mapred.utils.InputUtils;
  12. import com.aliyun.odps.mapred.utils.OutputUtils;
  13. import com.aliyun.odps.mapred.utils.SchemaUtils;
  14. /**
  15. * This is the trivial map/reduce program that does absolutely nothing other
  16. * than use the framework to fragment and sort the input values.
  17. *
  18. **/
  19. public class Sort {
  20. static int printUsage() {
  21. System.out.println("sort <input> <output>");
  22. return -1;
  23. }
  24. /**
  25. * Implements the identity function, mapping record's first two columns to
  26. * outputs.
  27. **/
  28. public static class IdentityMapper extends MapperBase {
  29. private Record key;
  30. private Record value;
  31. @Override
  32. public void setup(TaskContext context) throws IOException {
  33. key = context.createMapOutputKeyRecord();
  34. value = context.createMapOutputValueRecord();
  35. }
  36. @Override
  37. public void map(long recordNum, Record record, TaskContext context)
  38. throws IOException {
  39. key.set(new Object[] { (Long) record.get(0) });
  40. value.set(new Object[] { (Long) record.get(1) });
  41. context.write(key, value);
  42. }
  43. }
  44. /**
  45. * The main driver for sort program. Invoke this method to submit the
  46. * map/reduce job.
  47. *
  48. * @throws IOException
  49. * When there is communication problems with the job tracker.
  50. **/
  51. public static void main(String[] args) throws Exception {
  52. JobConf jobConf = new JobConf();
  53. jobConf.setMapperClass(IdentityMapper.class);
  54. jobConf.setReducerClass(IdentityReducer.class);
  55. jobConf.setNumReduceTasks(1);
  56. jobConf.setMapOutputKeySchema(SchemaUtils.fromString("key:bigint"));
  57. jobConf.setMapOutputValueSchema(SchemaUtils.fromString("value:bigint"));
  58. InputUtils.addTable(TableInfo.builder().tableName(args[0]).build(), jobConf);
  59. OutputUtils.addTable(TableInfo.builder().tableName(args[1]).build(), jobConf);
  60. Date startTime = new Date();
  61. System.out.println("Job started: " + startTime);
  62. JobClient.runJob(jobConf);
  63. Date end_time = new Date();
  64. System.out.println("Job ended: " + end_time);
  65. System.out.println("The job took "
  66. + (end_time.getTime() - startTime.getTime()) / 1000 + " seconds.");
  67. }
  68. }
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