> -----Original Message----- > From: IBM Mainframe Discussion List > [mailto:[email protected]] On Behalf Of Frank Swarbrick > Sent: Friday, October 02, 2009 1:44 PM > To: [email protected] > Subject: multiple jobs / same name > > I have a complaint (shocking, I know). What is the reasoning > behind MVS not allowing more than one job with the same name > to run at the same time? For instance just now I wanted to > do an IDCAMS PRINT on two files. I do this often on VSE with > a job I have set up that has this: > PRINT INFILE(FILE1) - > DUMP > > I simply change FILE1 to whatever the name is and submit it. > Then if I have another one I change it again to the second > file and submit it. These are large files so it makes sense > to have them both run at the same time, rather than one after > the other. But unless I change the job name on the JOB card > on z/OS the second one won't run until the first is done. > Annoying! Why on earth is this restriction present? Does it > actually *help* some situations, or is it simply one of those > annoying things that has existed forever and will probably > never be changed? > > Thanks (really!), > Frank > > -- > > Frank Swarbrick
That is buried in the mists of pre-history (it was a HASP reason). However, in today's z/OS JES2 you can specify the parameter DUPL_JOB=NODELAY on the JOBDEF JES2 initialization statement to remove this restriction. Also, you can specify it in the JOBCLASS(c) initialization statement to only affect jobs in that specific class(es). This will allow multiple jobs with the same name to run at the same time. I'm not an expert on this. But, as I understand it, HASP was an "add on" to OS/MVT to replace its very primitive job system. And this was in the days before there were such things as job numbers (from an MVT perspective). So, to be able to track the relationship between an MVT job and a HASP job, the name of the job while executing had to be unique. This "one at a time" has persisted to this day as a primitive way to try to ensure that jobs run in a specific sequence. Programmers especially think that if "n" jobs are submitted in the same job class, then they are guaranteed to run in the order submitted. They really aren't guaranteed, but it happens in 99% of the time. And is usually set up to try to guarantee it. -- John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets(r) 9151 Boulevard 26 * N. Richland Hills * TX 76010 (817) 255-3225 phone * (817)-961-6183 cell [email protected] * www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
