[crackez]

Negativo friendo.

The mainframe is turning into a middleware layer running on Enterprise Linux. We've containerized the mainframe at this point, and I mean that directly - eg. Running jcl, multiple CICS regions, all in COBOL that originated on z/OS is now running in k8s on amd64.

[kjellsbells]

I hope you're right, but many comments here on HN suggest their experience with mainframes is very different. z/OS and its predecessors provided so many services completely transparently to the application that a mainframe to modernity migration is doomed to fail unless it can completely emulate (or design around) the capabilities provided by the OS and other subsystems.

Even ignoring the needs of the super high end customers like banks (eg, cpus in lockstep for redundancy), being able to write your app and just know that inter-node message passing is guaranteed, storage I/O calls are guaranteed, failover and transaction processing is guaranteed, just raises the bar for any contender.

K8s is wonderful. Can it make all the above happen? Well, yes, given effort. If I'm the CTO of an airline, do I want to shell out money to make it happen, risk it blowing up in my face, or should I just pay IBM to keep the lights on, kick the can down the road, and divert precious capital to something with a more obvious ROI? I think their "no disasters on my watch/self preservation" instinct kicks in, and I can't really blame them.

HN thread:

https://news.ycombinator.com/item?id=36846195

[Spooky23]

Like anything else, some places are awesome, some not. I’ve seen both. The worst ones are just like modern places with overcustomized PeopleSoft or SAP - except the blobs of off the shelf software were purchased 30 years ago by people long dead.

Other places stopped development 20 years ago and surrounded the mainframe with now legacy middleware. A lot of the “COBOL” problems with unemployment systems during COVID were actually legacy Java crap from the early 2000s that sat between the mainframe and users.

[Muromec]

>If I'm the CTO of an airline, do I want to shell out money to make it happen, risk it blowing up in my face, or should I just pay IBM to keep the lights on

But that's the thing, we are at the point when "keep paying IBM" isn't the acceptable answer anymore.

[kjs3]

I hope you're right, but many comments here on HN suggest their experience with mainframes is very different.

HN is not the place to seek authoritative experience with something like COBOL.

[zifpanachr23]

I work on them full time (not doing application programming and so I can't really speak to COBOL) but this is mostly accurate as it relates to the environment.

A lot of these services are completely transparent to the application, but that doesn't mean they are totally transparent to the entire programming staff. The system configuration and programming is probably more complicated (and lower level usually, certainly YAML hasn't really caught on in the Mainframe world outside of the Unix environment) all things considered than something like k8s.

So that's where a lot of the complications come in to play. Every application migration is going to necessarily involve recreating in Kubernetes or some other distributed system a lot of those same automations and customizations that decades worth of mainframe systems programmers have built up (many of whom will no longer be around). And however bad the COBOL labor shortage really is, the shortage of mainframe assembly programmers and personel familiar with the ins and ours of the hardware and system configuration is 10x worse.

It should also be noted that not everywhere that has a mainframe has this issue. There is a wide disparity between the most unwieldy shops and the shops that have done occasional migrations to new LPARs and cleaned up tech debt and adopted new defaults as the operating system environments became more standardized over time. In the second case where a shop has been following the more modern best practices and defaults and has fewer custom systems lying around, ... the amount of effort for a migration (but also in a lot of ways, the motivation to take on a migration project) is lessened.

The case where some company is just absolutely desperate to "get off the mainframe" tend to be cases where the tech debt has become unmanageable, the catch 22 being that these are also the cases where migrations are going to be the most likely to fail due to all of the reasons mentioned above.

[accra4rx]

[I work as a SA] . There are many companies that don't have a original COBOL source code only compiled objects which has been running for more than few decades. How can you guarantee that it will run perfectly in k8s . Major companies can never take that risk unless you give them some insurance against failure

[Muromec]

There is a major drawback to this approach -- you need to have somebody who knows what they are doing. Total deal breaker in most of the places that have this problem in the first place.

[gerdesj]

"you need to have somebody who knows what they are doing"

That applies everywhere.

Your parent comment has managed to stuff a mainframe in a container and suddenly, hardware is no longer an issue. COBOL is well documented too so all good and so too will be the OS they are emulating. I used to look after a System 36 and I remember a creaking book shelf.

The code base may have some issues but it will be well battle tested due to age. Its COBOL so it is legible and understandable, even by the cool kids.

If you lack the skills to engage with something then, yes, there will be snags. If you are prepared to read specs, manuals and have some reasonable programing aptitude and so on then you will be golden. No need for geniuses, just conscientious hard workers.

It's not rocket science.

[Muromec]

It's not the point I'm trying to make. Yes you can do fancy stuff like that and de-mainframing COBOL is to run in on k8s is the path I would personally choose if I had to deal with it. It sounds like a lot of fun and the sense of accomplishment to finally have it running should be great.

The problem is -- it's very smart and unique, while organizations that have this kind of a problem don't want to depend on unique set of skills of a few highly capable individuals. Everything needs to be boring and people have to be replaceable.

In this paradigm, vendor java with aws lock-in is a cost, but in-house fancy stuff with cobol on k4s done by smart people in house is worse -- it's a risk.

[SonOfLilit]

The need applies everywhere, the difficulty of fulfilling it tends to be an order of magnitude more in places that tend to run COBOL.

I'm working at one. You wouldn't believe the stories.

[mathgorges]

This is fascinating to me as an ex-mainframer that now works on a niche hyperscaler. I would love to learn more!

Will you let me know some of the names in the space so that I can research more? Some cursory searching only brings up some questionably relavent press releases from IBM.

[yourapostasy]

Sounds like they’re talking about running IBM Wazi on Red Hat OpenShift Virtualization. As far as I know, there isn’t a System z-on-a-container offering, like you install from a Helm Chart or comes to you from an OCI registry. If it is the IBM I know, it’s completely out of reach of most homelab’ers and hobbyists.

IBM Wazi As A Service is supposed to be more affordable than the self hosted version and the Z Development and Test Environment (ZD&T) offering. ZD&T is around $5000 USD for the cheapest personal edition, so maybe around $2500-3500 USD per year?

[crackez]

Look up Micro Focus Enterprise Server and Enterprise Developer. They are now owned by Rocket.

[danielmarkbruce]

I second this and know some of the folks who work on Enterprise Server. Good people. They have a partnership of some sort with AWS and there is a bunch of decent docs around Enterprise Server on AWS

[danielmarkbruce]

Yup, but the COBOL application doesn't know you've done that.