[fredsmith219]

The vast majority of COBOL in production runs on IBM mainframes in conjunction with JCL (Job Control Language). If you are looking to offload COBOL from a mainframe to a cheaper platform JCL is a must. I love that this project exists but it’s only one half of a solution to migration off of a mainframe.

[guestbest]

Talking with mainframe guys for the last half decade, they seem to avoid JCL when they can and treat REXX like a super power.

[cwbriscoe]

Are these mainframe developers or system level guys. I wouldn't use REXX to run production batch processes. I would use REXX for TSO utilities and ISREDIT macros. JCL is pretty much a must for running batch processing. It is waaaaay more simpler and re-startable than trying to do the same thing with REXX.

[YeGoblynQueenne]

Yes, but you use the REXX to generate the JCL.

[cwbriscoe]

Hmm. I guess I am just not seeing the use case but not saying there isn't one. JCL, isn't hard to do. You usually just copy 80% of it from other jobs and change dataset names, etc...

[YeGoblynQueenne]

Yes, automatically :)

[__d]

When I last used COBOL (early 90's) we had a heap of JCL, for sure, but the real-time system used CICS for everything.

Is it still a thing? What's the FOSS solution for transaction monitoring?

[macintux]

I’m unfamiliar with JCL, but from a quick search it sounds like most scripts don’t use much of the language. Still, I’d bet that most of the JCL functionality is used if you look at a decent-sized collection of scripts.

How much of the full JCL do you think would be necessary to reimplement in order to get, say, 30% of the existing scripts to work?

[smackeyacky]

From memory of working with mainframe programmers back in the 1990s, it isn't just JCL you need. Cobol programs typically used databases and transaction monitors as well.

If you're lucky the database will be one of IBM's SQL databases. If you're unlucky it will be something like IMS.

[macintux]

You just reminded me that in the mid-90s I took a TCP/IP workshop where the other attendees worked on mainframes. The chasm between what I was familiar with and what they were was impressively wide.

[cwbriscoe]

I have heard horror stories about IMS but have been fortunate to never have to use it. DB2 is pretty decent and very reliable.

[chasil]

IMS is a hierarchical database.

Under OS2200, DMS is also a hierarchical database, and (unfortunately) we use it.

My developers have described it as the Fort Knox of databases, being very difficult to get data out.