Running a job on a particular instance within the RAC

Have only asked one question in the past, but now I need help so here goes -- as clearly as I can...

I have a job that needs to be run on a regular basis.  The job takes some text files (payroll data) that is downloaded from a mainframe and imports it into our newly designed system written in .net and Oracle (read, NOT mainframe).  The job is an Oracle Scheduler Job and my database is Oracle 10g RAC.

From what I understand of DBMS_SCHEDULER, I can specify a "service" under which to run the job, and this supposedly will get the job to run only on the instance I specify.  This is what I WANT to do since the files are copied into the same machine every night, therefore, run the job from the instance on that machine.  My problem is that I cannot find documentation on how to set this up completely right.

My script for setting up the job is below... what am I missing?

BEGIN
  SYS.DBMS_SCHEDULER.CREATE_JOB
    (
       job_name        => 'TLB_CORE_JOB'
      ,start_date      => TO_TIMESTAMP_TZ('2007/10/25 02:00:00.000000 -05:00','yyyy/mm/dd hh24:mi:ss.ff tzh:tzm')
      ,repeat_interval => 'FREQ=DAILY;BYHOUR=2'
      ,end_date        => NULL
      ,job_class       => 'AUTO_TASKS_JOB_CLASS'
      ,job_type        => 'STORED_PROCEDURE'
      ,job_action      => 'TLB_CORE_PKG.MAIN'
      ,comments        => 'This job will run the core import processes, including updating people, their addresses, and the Labor Distribution table.'
    );
  SYS.DBMS_SCHEDULER.SET_ATTRIBUTE
    ( name      => 'TLB_CORE_JOB'
     ,attribute => 'RESTARTABLE'
     ,value     => FALSE);
  SYS.DBMS_SCHEDULER.SET_ATTRIBUTE
    ( name      => 'TLB_CORE_JOB'
     ,attribute => 'LOGGING_LEVEL'
     ,value     => SYS.DBMS_SCHEDULER.LOGGING_RUNS);
  SYS.DBMS_SCHEDULER.SET_ATTRIBUTE
    ( name      => 'TLB_CORE_JOB'
     ,attribute => 'MAX_FAILURES'
     ,value     => 1);
  SYS.DBMS_SCHEDULER.SET_ATTRIBUTE_NULL
    ( name      => 'TLB_CORE_JOB'
     ,attribute => 'MAX_RUNS');
  BEGIN
    SYS.DBMS_SCHEDULER.SET_ATTRIBUTE
      ( name      => 'TLB_CORE_JOB'
       ,attribute => 'STOP_ON_WINDOW_CLOSE'
       ,value     => FALSE);
  EXCEPTION
    -- could fail if program is of type EXECUTABLE...
    WHEN OTHERS THEN
      NULL;
  END;
  SYS.DBMS_SCHEDULER.SET_ATTRIBUTE
    ( name      => 'TLB_CORE_JOB'
     ,attribute => 'JOB_PRIORITY'
     ,value     => 3);
  SYS.DBMS_SCHEDULER.SET_ATTRIBUTE
    ( name      => 'TLB_CORE_JOB'
     ,attribute => 'SCHEDULE_LIMIT'
     ,value     => '+001 00:00:00');
  SYS.DBMS_SCHEDULER.SET_ATTRIBUTE
    ( name      => 'TLB_CORE_JOB'
     ,attribute => 'AUTO_DROP'
     ,value     => FALSE);

  SYS.DBMS_SCHEDULER.ENABLE
    (name                  => 'TLB_CORE_JOB');
END;
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