> Today, IBM is the only mainframe manufacturer AFAIK Fujitsu still manufacture mainframes
Also HP NonStop (Tandem).
The IBM mainframe: How it runs and why it survives
31–40 of 195 posts
Re: The IBM mainframe: How it runs and why it survives
#32The 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…
Migrating a suite of programs written w/ COBOL, CICS, DB2 from z/OS to Linux is fairly straightforward. MicroFocus COBOL compiles IBM COBOL, DB2 runs on Linux or you can swap out another RDBMS. The CICS part requires a simple runtime easily implemented in C plus a new scanner to replace the calls in your programs.
I was part of a 4 person team that knocked this out in under a year. 1,000's of mainframe programs running w/o change (at the time) on Unix. This was in the 90s.
Re: The IBM mainframe: How it runs and why it survives
#33"They’re designed to process large amounts of critical data while maintaining a 99.999 percent uptime—that’s three seconds of outage per year." Very wrong. Five nines is five minutes and 13 seconds of cumulative downtime in a year[0]. Three seconds of downtime in a year is seven nines[1]. [0] - https://uptime.is/five-nines [1] - https://uptime.is/99.99999
I've always heard that as "scheduled uptime" or "unscheduled outages". When I worked in a mainframe shop, they used to IPL (reboot) the mainframe every Sunday morning. That down time was never considered as part of the SLA.
Re: The IBM mainframe: How it runs and why it survives
#34I've never used or even seen a mainframe in 26 years in the tech industry. My brother in law works for a bank and basically the business runs on it.
The hardware and software are certainly impressive but does anyone use a mainframe for a new project and not just upgrading or expanding an existing system?
I'm in integrated circuit design and we have compute clusters with thousands of CPUs. For some jobs we use a single machine with 128 CPUs and over 2TB RAM. Some steps get split over 30 machines in parallel. All of this EDA / chip design software migrated from Sun and HP workstations in the 1980's and 90's to Linux x86 in the 2000's. I think some of it ran on mainframes in the 70's but does anyone use mainframes for scientific style calculations or is it just financial transaction / database kind of stuff?
Re: The IBM mainframe: How it runs and why it survives
#35The 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…
Used to be great for vector processing for numerical analysis, although not sure anymore
Re: The IBM mainframe: How it runs and why it survives
#36Earlier quoted context omitted.
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.
There's an article where their pitch was "It's the new AS/400"
Or, you could just buy a new AS/400 that already does all that.
Re: The IBM mainframe: How it runs and why it survives
#37If you zoom out, the ecosystem is very comparable to running on AWS or similar. It's an opinionated environment with proprietary answers for how to do things like scheduling, short-lived tasks, long-lived tasks, storage allocation, networks, monitoring, forced version upgrades, etc.
I wonder if IBM can offer a mainframe in the cloud. Its everything a mainframe provides but all off-site and priced for my size.
It's one of the major ways to get a mainframe these days, even companies you'd expect to have one on premises might actually have a lease on one running in IBM datacenter with VPN to internal network.
Re: The IBM mainframe: How it runs and why it survives
#38The 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…
Used to be great for vector processing for numerical analysis, although not sure anymore
Since z13 vector instructions are supported again. But I doubt anybody uses them.
Re: The IBM mainframe: How it runs and why it survives
#39Earlier quoted context omitted.
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.
Getting stupefying amounts of I/O on AWS is as simple as turning a knob and getting out your credit card. The kind of throughput quoted in the article—48GB/s—is achievable on AWS for $250k/year, list price.
Re: The IBM mainframe: How it runs and why it survives
#40Earlier quoted context omitted.
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.
I think its only IBM people who calls computers midrange ;)