> Today, IBM is the only mainframe manufacturer
AFAIK Fujitsu still manufacture mainframes
The IBM mainframe: How it runs and why it survives
21–30 of 195 posts
Re: The IBM mainframe: How it runs and why it survives
#22Earlier quoted context omitted.
It persists in many places due to the deeply ingrained belief that, for one reason or another, it would be technically, practically, or economically impossible to migrate functionality off the mainframe. Somehow the people in charge of these systems have managed to convince large enterprises of this for decades . And now we are in a situation where their long held beliefs have become true because nobody is around tha…
Before we even get to the costs of a migration, what is the reason for the migration?
Some people just like to see the world burn. Move fast, break things. Like my bank, ATM, pharmacy, shipping mgmt, hospitals, paycheck services, utility grids...
And then in 5 years someone can rewrite it all again because something else will be cooler and my code will be technical debt.
Re: The IBM mainframe: How it runs and why it survives
#23> Today, IBM is the only mainframe manufacturer AFAIK Fujitsu still manufacture mainframes
Oxide could probably be considered a "modern mainframe" if you squint. The architecture is of course much different, but server CPUs from the likes of AMD are gradually catching up with the purpose-built stuff in raw power and I/O capabilities.
Re: The IBM mainframe: How it runs and why it survives
#24Here’s a recent-ish Changelog podcast with one of the few professors who teaches about IBM mainframes and COBOL and is part of the Open Mainframe Project, https://changelog.com/podcast/524
Re: The IBM mainframe: How it runs and why it survives
#25Earlier quoted context omitted.
Before we even get to the costs of a migration, what is the reason for the migration?
People may assume that a lot of this mainframe software is "running just fine" but nothing could be farther from the truth. Often you will find that this software was fine when it was written 40-50 years ago, but now it has a lot of deferred maintenance and upgrades which are now a "big problem". Is it a problem that an application that can move millions of dollars is only secured by a strictly 8 character alphanumer…
Certainly. A good reason for a migration is that we are in a place where we need to do something major--whether that's modernizing the software on the mainframe that isn't doing the job, moving everything to new platform(s) (including potentially cloud), or some combination of the two--the latter being a pretty common strategy these days. At that point, just adding more duct tape is probably the wrong approach, at least in the medium to long term.
Re: The IBM mainframe: How it runs and why it survives
#26Earlier quoted context omitted.
It persists in many places due to the deeply ingrained belief that, for one reason or another, it would be technically, practically, or economically impossible to migrate functionality off the mainframe. Somehow the people in charge of these systems have managed to convince large enterprises of this for decades . And now we are in a situation where their long held beliefs have become true because nobody is around tha…
> It persists in many places due to the deeply ingrained belief that, for one reason or another, it would be technically, practically, or economically impossible to migrate functionality off the mainframe. It is never technical or pratical reasons, always economic reasons. To use contemporary vocabulary, you "just" need to replicate a "multi tenant HA cloud environment" to migrate from a mainframe at great cost. > An…
I'm not sure how much water the multi tenant HA argument holds, these institutions are already doing that on AWS / Azure / k8s for the more modern apps. Rewriting all the old crusty COBOL code might be a different story.
Re: The IBM mainframe: How it runs and why it survives
#27My partner does very technical systems hacking on z/OS. They have a huge problem hiring new programmers. His colleagues are all well over 65 and are inevitably retiring (or worse). It seems like a real problem for the future of the platform.
Re: The IBM mainframe: How it runs and why it survives
#28> Today, IBM is the only mainframe manufacturer AFAIK Fujitsu still manufacture mainframes
Oxide could probably be considered a "modern mainframe" if you squint. The architecture is of course much different, but server CPUs from the likes of AMD are gradually catching up with the purpose-built stuff in raw power and I/O capabilities.
Oxide hardware is more comparable to a midrange computer. Though they are apparently planning to add support for having multiple physical racks in a single managed "silo", which enables HA scenarios and gets a bit closer to what mainframes provide.
Re: The IBM mainframe: How it runs and why it survives
#29Earlier quoted context omitted.
> It persists in many places due to the deeply ingrained belief that, for one reason or another, it would be technically, practically, or economically impossible to migrate functionality off the mainframe. It is never technical or pratical reasons, always economic reasons. To use contemporary vocabulary, you "just" need to replicate a "multi tenant HA cloud environment" to migrate from a mainframe at great cost. > An…
I'm not sure how much water the multi tenant HA argument holds, these institutions are already doing that on AWS / Azure / k8s for the more modern apps. Rewriting all the old crusty COBOL code might be a different story.
Getting the same performance out of AWS as a local mainframe is neither trivial nor cheap for a lot of the workloads these systems are running.
Re: The IBM mainframe: How it runs and why it survives
#30The reason mainframe persists is it's a pretty slick development and deployment environment. A lot things you might cobble together as dependencies - like maybe a database or a message queue, or observability facilities or even deployment strategies like hot-hot deployments - they're all just built in to the platform. That means they're trivial to consume and they're fully supported by one vendor. It's like the world…
It persists in many places due to the deeply ingrained belief that, for one reason or another, it would be technically, practically, or economically impossible to migrate functionality off the mainframe. Somehow the people in charge of these systems have managed to convince large enterprises of this for decades . And now we are in a situation where their long held beliefs have become true because nobody is around tha…
I have worked on an RFP for migration. It persists because the cost for migrating can be quite high -- many mainframe environments have many applications with complex sets of dependencies (after decades, not surprising). No one doubts that it could be migrated, but it is not a trivial undertaking.
When folks have replaced significant enough chunks with other apps, or otherwise made the prospect less daunting, then it may happen. It just comes down to cost and risk management.