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I previously led a significant chunk of developer evangelism at IBM. Mainframes are unbelievably powerful, feature-full, and cost-effective. You are almost cert

• tines 3y ago
  What even is a mainframe, exactly?
  • abtinf 3y ago
    A modern mainframe is a system specialized in extremely high transaction throughput at extremely low cost-per-transaction, while guaranteeing data durability and computational correctness.
    • tines 3y ago
      Sounds like a computer. Why would getting access to one to play around encourage people to buy one? In other words, it sounds like a quantitative difference rather than a qualitative one.
      • _ea1k 3y ago
        True. I find it interesting how difficult that they find it to put the benefits into words that don't sound like a brochure. Surely there should be some specifications behind this? Benchmarks?
        • rbanffy 3y ago
          Anandtech ran a story when the z16's CPU was announced: https://www.anandtech.com/show/16924/did-ibm-just-preview-the-future-of-caches https://www.anandtech.com/show/16924/did-ibm-just-preview-th...
        • gitfan86 3y ago
          I worked on them a bit while at IBM. You can open a terminal and come back in a month and it will still be there. Unlikely kunernetes where containers regularly go down. You can obviously achieve high reliability with Kunernetes, but you'll need queues and retry logic, that you don't need with SystemZ.
          • tryauuum 3y ago
            Is this where we are right now as a society: a terminal which doesn't die in a month is presented as an achievement? I assume the achievement part is that any CPU can be replaced transparently to the terminal running?
            • gitfan86 3y ago
              Yes, Hard drives can die, power supply can die, another user can write an infinite loop and it will not kill your terminal. Not a big deal today, but in the 80s hard drives died more frequently and a bank losing just 5 seconds of transactions could cost them millions.
            • vidarh 3y ago
              I've not worked with a mainframe, but I've worked with an IBM storage system that worked on similar principles: We could connect our systems via dual controllers, to separate bays of controllers on the storage array. You could pull whole bays of controller cards and the system would stay up. You could pull whole bays of hard drives, and the system would stay up. You could pull power supplies and it'd remain up. You could swap RAM and CPUs in the servers managing it without shutting them down, but you could also pull one of those servers, and it'd remain up. If stuff started failing, and IBM engineer would show up because the system would call home. This was around 25 years ago. It wasn't cheap, but it made a typical "modern" high availability setup look like a crude homemade toy. But as impressive as it was, there are just very few places where that impressiveness provides enough value to justify the cost. And having to deal with IBM.
      • zeroCalories 3y ago
        My understanding is that Z mainframes have a number of unique features to support those use cases. Stuff like hot swapping CPUs, and hundreds of IO coprocessors to avoid the main cores from getting blocked. Don't think they're just rebranded x86 machines, but not an expert.
      • mixmastamyk 3y ago
        Hah, try getting ECC memory from a PC supplier. Surprisingly difficult and expensive when it should have been default twenty years ago.
        • themoonisachees 3y ago
          ECC memory is widely available, you can buy it on amazon, and if you have a contract with a server manufacturer they'll be happy to sell it to you. It's just not compatible with consumer CPUs (well, ddr5 is, but ddr4 and lower wasn't) because Intel was voluntarily segmenting the market to upcharge for server CPUs.
          • mixmastamyk 3y ago
            Sounds like a working solution is not as “widely available” as you suggest. Apple/Amd play similar games.
  • dgacmu 3y ago
    The other definition you got isn't bad, but I think it misses the point for this discussion: it is a rack or multi rack scale computer with built-in and centrally managed features for redundancy, failover, job allocation, scaling, etc. As an example, in many main frames, you can configure them with a spare set of CPUs, and if one of your CPUs fails, the replacement is brought online automatically and transparently, the code you write doesn't have to know about anything related to the failure.
    • rbanffy 3y ago
      One neat thing is that the hot spares can be used during boot to shorten the time to availability. Not sure LinuxONE boxes are bought like that, but for the Z-series you can buy the machine with more capacity than you pay for and pay for it to be enabled at a later point.
  • zjaffee 3y ago
    It's essentially a very large single clocked machine.
  • beAbU 3y ago
    I see it as similar to an on prem mini AWS cloud, with dedicated hardware for things like WAF, storage, compute, networking, lambdas and databases. I've heard it said a couple of times that working in cloud is closer to working on a mainframe than most want to admit.
    • teepo 3y ago
      That’s a good analogy. They are both platforms. The accelerators for things like Java, MQ, databases, are built in to the platform.
      • beAbU 3y ago
        Yep, cloud is really just an infinitely scalable mainframe.
  • Keyframe 3y ago
    Dave Plummer recently did a tour: https://www.youtube.com/watch?v=ouAG4vXFORc https://www.youtube.com/watch?v=ouAG4vXFORc It's definitely intriguing if it were.. I don't know, available to tinker with?
  • sillywalk 3y ago
    The IBM mainframe: How it runs and why it survives[0] from last fall. From way back in 2004[1], Commercial Fault Tolerance: A Tale of Two Systems compares the reliability / philosophy of IBM mainframes with Tandem Servers. [0] https://arstechnica.com/information-technology/2023/07/the-ibm-mainframe-how-it-runs-and-why-it-survives/ https://arstechnica.com/information-technology/2023/07/the-i... [1] http://www.engr.newpaltz.edu/~bai/CSE40534/bar04.pdf http://www.engr.newpaltz.edu/~bai/CSE40534/bar04.pdf
  • rahen 3y ago
    I'm astonished that people on Hacker News can ask such a question.
• alfalfasprout 3y ago
  And that lack of access is exactly why there's such a minimal ecosystem for open source tooling for mainframes.
  • fweimer 3y ago
    Open source software shouldn't be a problem. Pretty much anything that has been ported to 64-bit big-endian also works on s390x. The architecture is otherwise pretty non-challenging: always 4K pages, strong memory model. Pre-built binaries are a different matter, of course. The problem with access is not access as such, but the fact that the community hardware that you can access for free tends to be heavily oversubscribed (or maybe connected to a mismatched storage system).
    • jabl 3y ago
      I've never used a mainframe, but I did manage to introduce a small performance regression in gcc that someone complained about (I did fix it, yes). ;-) Turned out that s390 couldn't fuse cmp+jmp when the operand was a 8-bit value (_Bool). (That was a while ago, maybe current generation mainframe HW can do it?)
  • rbanffy 3y ago
    That is something that concerns me, but much more on the Z side than on the LinuxONE. On the Linux side, it's just a very fast computer.
  • sillywalk 3y ago
    "Only" $5,980.00 / user / year for the IBM Z Development & Test environment "personal edition" https://www.ibm.com/products/z-development-test-environment https://www.ibm.com/products/z-development-test-environment
• jhallenworld 3y ago
  Well you can run Hercules, the emulator. But you will then discover that the mainframe 3270 terminal user interface experience is terrible. A funny thing is this: there is a mainframe plug-in for Visual Studio Code. The idea is you do your COBOL development in Code, and only the plugin actually talks to the mainframe. A decade ago there was an Eclipse version of this.. This guy is showing all three ways: https://www.youtube.com/watch?v=_CYUYnKim7U https://www.youtube.com/watch?v=_CYUYnKim7U
  • bitwize 3y ago
    This kind of thing goes back five decades, actually. One of the earliest versions of Unix was PWB/Unix, for "Programmers' Workbench". It was designed as a system for AT&T engineers to author programs for the mainframe in a more sensible (for the time) environment and included software to submit jobs to the mainframe once the programs were written. The idea of "Unix as your IDE" is a deep, deep cut into Unix lore. https://en.m.wikipedia.org/wiki/PWB/UNIX https://en.m.wikipedia.org/wiki/PWB/UNIX
  • ethbr1 3y ago
    > the mainframe 3270 terminal user interface experience is terrible [... for new users] For expert users? I'd pit it against any interface you want. No-mouse + hands-on-keyboard + tab is hard to argue with. Sadly, the number of people who remember when GUIs could be driven from memory by keyboard-only has dwindled. Watch a 10-year veteran insurance employee use a green screen. Or as a counter-example, try to tab through your modern app du jour. (Modern developers often don't even bother to set indexes correctly)
    • pmontra 3y ago
      Except when you must set tabindex="0" or "-1" or Bootstrap's modals won't work. /grin
    • jl6 3y ago
      > Watch a 10-year veteran insurance employee use a green screen. Yes! I knew an Insurance customer service op who self-described as having no computer skills, but when I saw her using Reflection it was like watching a speedcuber savant.
• genmud 3y ago
  > Mainframes are unbelievably powerful, feature-full, and cost-effective. Maybe things have changed in the last 10 or 15 years, which is the last time I had a legit mainframe at a day job, but back then none of those things were true if you looked at it more than 20 minutes. I seem to remember nothing being included in the base mainframe… when you started to add things like DR and data duplication and virtualization, it became extremely expensive. Like on the DB side, effing Oracle was much cheaper.
  • rbanffy 3y ago
    Software licensing is expensive on them, but the people to keep your 99.999% uptime on your Kubernetes cluster aren't cheap either. And software licenses are one of the reasons why LinuxONE machines exist - they don't run z/OS, so you don't pay those licenses. You can even start a dozen VMs under an LPAR and run your Kubernetes cluster as if it were running on more common hardware that just never, ever fails. IIRC, you can run a special version of z/VM to manage your Linux VMs if you don't want to run Linux on the LPAR and use KVM for your VMs.
    • zeroCalories 3y ago
      Why bother using an LPAR if you're just gonna use kubernetes anyway? Why not just use one fat machine?
      • rbanffy 3y ago
        LPAR isolation happens on a lower level than z/VM or KVM. I don't think anyone has ever demonstrated a successful LPAR escape attack.
        • T3OU-736 3y ago
          The lack of escape demonstrations are likely, at least in partv due to a fairly low availability of those systems to the security researchers. I do not want to make it see that LPAR isolation is just waiting to be compromised, but security-by-unavailability also plays a part :)
• sonnyOrullivan 3y ago
  Sorry to say that your previous "evangelism" shows. It would be very interesting to hear what "unbelievably powerful" means (as in facts and numbers) compared to what a hyperscaler can provide. E.g. SPEC for CPU, GFLOPs, Tensor-ops for inference, latency and so on. Last I checked the consolidation story that claimed factors of savings took underutilized ancient Intel boxes as baseline. "feature-full" is also quite a stretch when it comes to software when most modern software needs to be ported or run in a Linux LPAR. In addition I'd question that not getting access easily is the main reason for the lack of adoption. It might be part of the problem but the other problem is that the thing is a niche product and IBM doesn't seem to be utterly successful in either explaining what the niche is nor how to extend it.
  • cbsmith 3y ago
    Last I checked, the Teliums had some pretty impressive numbers for memory bandwidth even compared to NVidia.
    • wmf 3y ago
      It doesn't. Mainframe terminology is so obfuscated that it's impossible to tell for sure but it sounds like less memory bandwidth than Genoa.
      • rbanffy 3y ago
        They are tailored to the traditional mainframe workloads (they do a lot of hardware/software co-design in their mainframe lineup), so I wouldn't expect a mainframe designed for the generic cloud hyperscale workloads. In any case, I have played with their LinuxONE Community Cloud service (running on the previous-gen z15) and it's very fast. The impression I get is that it doesn't need to wait for IO. There is a ton of very clever engineering on those machines and the z16 is a technological wonder. https://www.anandtech.com/show/16924/did-ibm-just-preview-the-future-of-caches https://www.anandtech.com/show/16924/did-ibm-just-preview-th...
    • sonnyOrullivan 3y ago
• gtirloni 3y ago
  > Mainframes are unbelievably powerful, feature-full, and cost-effective. I really doubt they are any more powerful than the best x86 rack servers. Their featurefulness is super dated. They are definitely not cost effective (good luck buying it from IBM without a huge contract). I pity the company that gets into mainframes today. Does that even exist? It's a proprietary nightmare.
  • cbsmith 3y ago
    IBM's proprietary nightmares have, historically, often been quite cost effective. AS/400 did eventually get too long in the tooth, but it had an amazing run for decades where it was extremely competitive for TCO.
    • gtirloni 3y ago
      Historically sums it up.
    • rbanffy 3y ago
      AS/400 is alive and well. It's now called IBMi and runs on POWER hardware.
      • cbsmith 3y ago
        Yeah, but they aren't so dominant on the TCO side as they once were.
  • coolkil 3y ago
    I also think most cloud providers are at least a vendor lock-in and maybe a proprietary nightmare. This way you at least got your own iron and ibm comes to fix parts when they break. (Without disabling your system) I do agree it is debatable whether it is beter than x86 most of the time cost savings projected when using a LinuxOne it is based on licensing. In the past oracle licenses where per core and we did a project where 8 ifl’s replaced 140 x86 cores
  • linksnapzz 3y ago
• 656565656565 3y ago
  this
  • 656565656565 3y ago
    downvoted so adding more this
• Thaxll 3y ago
  Cost effective is a stretch, I'm going to take a dumb example but the reliability of AWS step functions and S3 is good enough for 99.99% of most use cases for a 1/100 of the price. Mainframes are really powerful for some specific domain which most people on HN don't work in. Another take is that the most valuable company in the world ( tech one ) don't run their core businesses on mainframes.
  • mschuster91 3y ago
    > Mainframes are really powerful for some specific domain which most people on HN don't work in. Yeah, but the cases where mainframes run the show are the ones where stuff really matters, where actual human lives and existences are at stake: banks, insurances, governments, airlines, logistics. If Google has a day long outage, not much of value will be lost... but a large US bank, stock exchange or MC/Visa suddenly failing? That can be enough to trigger an actual bank run with all its consequences. (Of course, the argument can and should be made that no company should grow large enough to even be able to be such a threat, but that one will have to wait until at least 2028 to get solved)
• wmf 3y ago
  You are almost certainly better off buying a low-end mainframe than hiring a team of engineers to build yet another not-great data replication/recovery/HA system. To be clear, this only applies to regular mainframes running z/OS. LinuxONE machines, as the name implies, only run Linux where you'll have all the usual devops/SRE responsibilities.
  • rbanffy 3y ago
    The machines are still incredibly reliable, much more than a rack full of Dells.
    • themoonisachees 3y ago
      How so? What problems have IBM solved that dell can't figure out? In my experience sysadmin/SRE work is rarely about the reliability of the hardware and much more about machine management like predicting when you're running out of disk space etc.
• madmulita 3y ago
  One huge problem is you then have to deal with IBM.
  • jsiepkes 3y ago
    ...and you can check-out, but you can never leave (aka vendor lock-in).
    • rbanffy 3y ago
      LinuxONE is just one big Linux machine. There's very little to lock you in.
    • IgorPartola 3y ago
      Not many manage to get off AWS once they start either…
• vibepaaac21 3y ago
  It should be noted that I believe you can get access to Linux s390x boxes in the cloud for not very much money. It's the z/OS side of things that tends to be prohibitively expensive. Thats almost entirely due to software licensing and not hardware though. The hardware is really not much worse than POWER or any other non-x86 specialty hardware. So if you are making a product that could be big in the kinds of places that have a lot of mainframes, and you are offering an on-premises version, I'd say to go ahead and get a port to s390x tested (on Linux). It's very cheap to do and a potential selling point for a lot of large companies. Then from s390x to z/OS Unix it isn't all that much more work if you decide to take it all the way and offer official support, i.e. if somebody is going to sign a big contract where mainframe integration would be the differentiator between you and a competing product. Once you've got commitment for a contract of some kind I'm sure there are ways to get the access you would need to test under the expensive software.
  • yjftsjthsd-h 3y ago
    > I believe you can get access to Linux s390x boxes in the cloud for not very much money. Could you say where and what "not very much money" is? Like, are we talking $5 DO droplet equivalent or only a few hundred bucks a month? (but to be clear, this is a serious question; I'm a sucker for weird options and would be interested in running a s390x Linux box if it doesn't have too bad price+caveats)
    • electroly 3y ago
      Go to https://cloud.ibm.com/vpc-ext/provision/vs https://cloud.ibm.com/vpc-ext/provision/vs and choose North America > Washington DC > Washington DC 2. Click "Change image" and choose "IBM Z, LinuxONE", then pick Ubuntu. I get $0.09/hour for 1 vCPU/4GB RAM with storage extra. For fun, then try picking z/OS instead of Linux and see what that software license costs ($/hour). Take a guess first how much you think it'll be and then see if you're right.
• deleted 3y ago
  [deleted]
• hobobaggins 3y ago
  unbelievable powerful (within certain parameters), and definitely feature-full when compared to virtually any other highly-available platform. however, cost-effective? only if you're sitting on piles of cash. IBM mainframes are unique. They have 75 years of incredible research (IBM is often the #1 patent inventor in the world, year after year) into a platform that they completely control. This has produced an absolutely bulletproof product. But you gotta pay for that. Your other point that it would take a team of engineers to not-even-compete; yes, you're right about that. I'd love to own one, but I'd rather own my house first.
• unixhero 3y ago
  Yeah. Because of this animosity to learners, I block any purchase of IBM hardware or software. I carry a grudge.
  • madleprechaun 3y ago
    I did a mainframe apprenticeship for three years at IBM. Trying to learn anything on my own was damn near impossible. And that’s not even getting into the fact that IBM basically has to pay itself for access to some things between divisions. Though that could have been because my division was mostly ignored and eventually spun off.
• rodgerd 3y ago
  > Mainframes are unbelievably powerful, feature-full, and cost-effective. Having run IBM's own software (WAS and WAS derivatives) on both x86 and IFL, and found the same applications with the same workloads having a ratio of 1.5-2 x86:1 IFL, while the IFL itself is 1-2 orders of magnitude more expensive than an x86 core, that zVM is an order of magnitude more expensive than VMWare's hypervisors, that memory is two orders of magnitude more expensive than x86... well. I think you're long on the evangelism and short on the reality.
• bluesounddirect 3y ago
  So ibm cloud question. When ibm sells powervs vs a powerpc based setup in ibm cloud , which would land on a LinuxOne setup?
• yencabulator 3y ago
  > The reason you don’t is because it is basically impossible to get access to a mainframe you can play with and learn on. Once upon a time, we made a product that was selling to Fortune 500s, and IBM loaned one of the smaller zSeries to us to make sure the product was running well in a Linux VM on it. The thing only fit in the elevator after we took it out of the wood crate... A lot of the porting effort happened on Hercules, an emulator: http://www.hercules-390.org/ http://www.hercules-390.org/