hadoop job control

1. 순차적으로 실행

   JobConf job1=new JobConf(getConf());
   ...
   JobClient.run(job1);
   
   JobConf job2=new JobConf(getConf());
   ...
   JobClient.run(job2);
   
   JobConf job3=new JobConf(getConf());
   ...
   JobClient.run(job3);

2. 의존관계의 연결

   JobConf job1=new JobConf(getConf());
   ...
   JobConf job2=new JobConf(getConf());
   ...
   JobConf job3=new JobConf(getConf());
   ...
   JobConf job4=new JobConf(getConf());
   ...
   JobControl con=new JobControl("DependancyJob");
   org.apache.hadoop.mapred.jobcontrol.Job wrapperJob1 =new org.apache.hadoop.mapred.jobcontrol.Job(job1);		
   con.addJob(wrapperJob1);
   
   org.apache.hadoop.mapred.jobcontrol.Job wrapperJob2 =new org.apache.hadoop.mapred.jobcontrol.Job(job2);		
   con.addJob(wrapperJob2);
   
   org.apache.hadoop.mapred.jobcontrol.Job wrapperJob3 =new org.apache.hadoop.mapred.jobcontrol.Job(job3);		
   con.addJob(wrapperJob3);
   wrapperJob3.addDependingJob(wrapperJob1);
   wrapperJob3.addDependingJob(wrapperJob2);			
   
   org.apache.hadoop.mapred.jobcontrol.Job wrapperJob4 =new org.apache.hadoop.mapred.jobcontrol.Job(job4);		
   con.addJob(wrapperJob4);
   wrapperJob4.addDependingJob(wrapperJob3);
   
   con.run();

3. 여러개의 Mapper와 한개의 Reducer

   JobConf tmConf = new JobConf(false);
   ChainMapper.addMapper(conf, MapperClass, LongWritable.class, Text.class, Text.class, IntWritable.class, true, tmConf);
   
   JobConf umConf = new JobConf(false);
   ChainMapper.addMapper(conf, MapperClass, Text.class, IntWritable.class, Text.class, IntWritable.class, true, umConf);
    
   JobConf wrConf = new JobConf(false);
   ChainReducer.setReducer(conf, ReducerClass, Text.class, IntWritable.class, Text.class, IntWritable.class, true, wrConf);
    
    /*JobClient client = new JobClient(conf);
    RunningJob job = client.submitJob(conf);
    client.monitorAndPrintJob(conf, job);*/
    
    RunningJob job = JobClient.runJob(conf);