Parallel Processing Using Jobs

Parallel Processing Using Jobs

We'll create the 'job queue' and fill it with sample 'waitfor delay' commands with variable wait time using rand() function. The jobs will just simulate the work.

create table #job_queue (id int identity(1,1) primary key,exe_proc varchar(255))

declare @create_job nvarchar(max),@db_name sysname,@job_name varchar(255)

declare @val int,@command nvarchar(max),@delay varchar(16),@i int

set @db_name=db_name()

set @i=1

while @i<=100

    begin

        insert #job_queue values('waitfor delay ''''0:0:'+cast(ceiling(rand()*10) as varchar(3))+'''''')

        set @i=@i+1

    end

2. Starting the main loop. Create the SQL for the job first:

while exists(select 1 from #job_queue)

 begin

  select top 1 @val=id,@command=exe_proc from #job_queue

  set @job_name='_insert_base_job_name_'+cast(@val as varchar(3))

  set @create_job='

  USE [msdb]

  DECLARE @jobId BINARY(16)

  EXEC  msdb.dbo.sp_add_job 

      @job_name='''+@job_name+''',

      @enabled=1,

      @delete_level=3,

      @category_name=N''[Uncategorized (Local)]'',

      @owner_login_name=N''sa''

  EXEC msdb.dbo.sp_add_jobserver 

      @job_name='''+@job_name+''', 

      @server_name = N'''+@@servername+'''

  EXEC msdb.dbo.sp_add_jobstep 

      @job_name='''+@job_name+''', 

      @step_name=N''execute'',

      @step_id=1,

      @cmdexec_success_code=0,

      @on_success_action=1,

      @on_fail_action=2,

      @os_run_priority=0, @subsystem=N''TSQL'',

      @command='''+@command+''',

      @database_name='''+@db_name+''',

      @flags=0

  EXEC msdb.dbo.sp_update_job 

      @job_name='''+@job_name+''',

      @enabled=1,

      @start_step_id=1,

      @delete_level=3,

      @category_name=N''[Uncategorized (Local)]'',

      @owner_login_name=N''sa'''

3.Create the job and start it. Then remove the command from the queue:

exec sp_executesql @create_job

exec msdb.dbo.sp_start_job @job_name

delete top (1) #job_queue

print 'starting '+@job_name

4. Monitor number of jobs already running and wait until the number drops under 30 before starting a new one:

while (select count(*) from msdb.dbo.sysjobs_view job

         inner join msdb.dbo.sysjobactivity activity

         on (job.job_id = activity.job_id)

         where run_Requested_date is not null 

         and stop_execution_date is null

         and job.name like  '%_Card360_peter_jobs_%')>=30

  waitfor delay '0:0:2'

 end

drop table #job_queue