Implementation WMAgent Refactoring

Initial plan for implementation

schema changes

1. need a new work unit table to keep track the which lumis/events are successfully processed. (not considering optimization but minimal changes)

   wmbs_work_unit
   CREATE TABLE wmbs_work_unit (
             id           INTEGER          PRIMARY KEY AUTO_INCREMENT,
             taskid       INTEGER          NOT NULL,
             fileid       INTEGER          NOT NULL, #(fake file for mc)
             run          INTEGER          NOT NULL,
             lumi         INTEGER          NOT NULL,
             firstevent   INTEGER          NOT NULL,
             lastevent    INTEGER          NOT NULL,
             status       INT(1)           DEFAULT 0,
             FOREIGN KEY (taskid)
             REFERENCES wmbs_workflow(id) ON DELETE CASCADE)  

fileid, run, lum can be replaced by one id if add unique id in wmbs_file_runlumi_map table.

1. above table need to be populated when fileset and subscription is created (before job splitting happens)

2. wmbs_job_mask table should be modified (or replaced) so it contains relationship between work unit and job id.

3. wmbs_job table contains 3 states (success, failure, partial_success) Not sure this is needed but maybe need for retrying logic

4. We might need the association between output file and wmbs_work_unit

job splitting changes.

1. (Job splitting need to happen multiple times not just for initially over the input. To make this simpler, splitting happens over wmbs_work_unit not over files.

job accounting changes

1. (JobAccounter needs to update wmbs_work_unit status, also wmbs_work_unit and output file accociation)

monitoring changes??

1. we might still able to track jobs which would contain work unit information.