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Jacobi is one of 70 IBM Fellows (think IBM internal professors, free reign over a research budget, you gain the title with technical prowess plus business acume

by froh 2y ago

Jacobi is one of 70 IBM Fellows (think IBM internal professors, free reign over a research budget, you gain the title with technical prowess plus business acumen) at the heart of the Mainframe success is this: > I’d say high-availability and resiliency means many things, but in particular, two things. It means you have to catch any error that happens in the system - either because a transistor breaks down due to wear over the lifetime, or you get particle injections, or whatever can happen. You detect the stuff and then you have mechanisms to recover. You can't just add this on top after the design is done, you have to be really thinking about it from the get-go. and then he goes into details how that is achieved. the article nicely goes into some details. oh and combine the 99.9999999% availability "nine nines" with insane throughput. as in real time phone wiretapping throughput, or real time mass financial transactions, of course. or a web server for an online image service. or "your personal web server in a mouse click", sharing 10.000 such virtual machines on a single physical machine. which has a shared read only /ist partition mounted into all guests. not containers, no, virtual machines, in ca 2006... "don't trust a computer you can lift"

wolf550e 2y ago
The amount of throughput you can get out of AMD EPYC zen5 servers for the price of a basic mainframe is insane. Even if IBM wins in single core perf using absurd amount of cache and absurd cooling solution, the total rack throughput is definitely won by "commodity" hardware.
- rbanffy 2y ago
  Maybe, but then you need to engineer the 99.99999% uptime yourself. If it were actually cheaper, IBM wouldn’t be selling these machines so well.
  - oldpersonintx 2y ago
    [dead]
  - wolf550e 2y ago
    I don't think they are actually selling those machines so well. They have a captive legacy customer base, who else is buying those?
    - neverartful 2y ago
      From TFA: "Overall, Z is growing very healthily. LinuxONE is the fastest area of growth for us right now." However, he didn't elaborate or give any examples. If I were the interviewer, I would have followed it with: "Oh?! Can you provide some examples for the readers who believe that you only sell to captive audiences?"
      - rbanffy 2y ago
        If I had the need to ridiculously scale up a Linux workload, I’d immediately think LinuxONE or POWER. If I had the R&D budget for an on-prem VM hosting box, I’d seriously consider their smaller Express 4, which is not much pricier than a similarly capable x86 machine.
      - IanCutress 2y ago
        Because I've covered that in a previous video :) https://www.youtube.com/watch?v=ZVO55oxJ464 https://www.youtube.com/watch?v=ZVO55oxJ464
  - Muromec 2y ago
    They are mostly selling to the captive audience who is 40 years deep into COBOL and can't pull out until it falls on top of them.
    - feurio 2y ago
      Well, you know what to do - just sell a system that runs COBOL on an x86 cluster or Kubernetes or whatever, and you'll make billions! Be sure to allocate me a bunch of shares for giving you the idea.
    - pjmlp 2y ago
      Many of those machines are running Java workloads, also COBOL isn't the only mainframe language, and the best thing in terms of security is that they don't use C as systems language, rather saner stuff with proper arrays, strings and bounds checking. That is why Unisys ClearPath MCP is still a thing, tracing back to its Burroughs 1961 heritage, security above all.
      - rbanffy 2y ago
        Java workloads might be easier to port away from but aren’t MCP machines x86-based nowadays? Unisys did a ton of work for Microsoft making itself obsolete by adding a lot to their secret multiprocessor stuff to Windows. It’s amazing how Microsoft convinced so many companies to shoot their feet.
        pjmlp 2y ago
        They still use NEWP as systems language, there is no C stuff to exploit.
        rbanffy 2y ago
        I had a lot of trouble with the idiosyncratic ways of MCP, and I have no doubt Tron's villain was named after it.
    - rbanffy 2y ago
- neverartful 2y ago
  These comments always come up with every mainframe post. It's not only about performance. If it were it would be x86 or pSystems (AIX/POWER). The reason customers buy mainframes is RAS (reliabililty, availability, scalability). Notice that performance is not part of RAS.
  - jiggawatts 2y ago
    You and the parent are both "missing the point", which is sadly not talked about by the manufacturer either (IBM). I used to work for Citrix, which is "software that turns Windows into a mainframe OS". Basically, you get remote thin terminals the same as you would with an IBM mainframe, but instead of showing you green text you get a Windows desktop. Citrix used to sell this as a "cost saving" solution that inevitably would cost 2-3x the same as traditional desktops. The real benefit for both IBM mainframes and Citrix is: latency. You can't avoid the speed of light, but centralising data and compute into "one box" or as close as you can get it (one rack, one data centre, etc...) provides enormous benefits to most kinds of applications. If you have some complex business workflow that needs to talk to dozens of tables in multiple logical databases, then having all of that unfold in a single mainframe will be faster than if it has to bounce around a network in a "modern" architecture. In real enterprise environments (i.e.: not a FAANG) any traffic that has to traverse between servers will typically use 10 Gbps NICs at best (not 100 Gbps!), have no topology optimisation of any kind, and flow through at a minimum one load balancer, one firewall, one router, and multiple switches. Within a mainframe you might have low double-digit microsecond latencies between processes or LPARs, across an enterprise network between services and independent servers its not unusual to get well over one millisecond -- one hundred times slower. This is why mainframes are still king for many orgs: They're the ultimate solution for dealing with speed-of-light delays. PS: I've seen multiple attempts to convert mainframe solutions to modern "racks of boxes" and it was hilarious to watch the architects be totally mystified as to why everything was running like slow treacle when on paper the total compute throughput was an order of magnitude higher than the original mainframe had. They neglected latency in their performance modelling, that's why!
    - le-mark 2y ago
graycat 2y ago
Virtual machine changes since CP67/CMS?
- froh 2y ago
  ah, a connoisseur... alas the last bottle of that was served in 1972 the current incarnation is z/VM, which started 2000. it is rumored to have one or two new features.
bitsandboots 2y ago
The heart of the mainframe success was being first to make a real OS and real forward compatibility. The heart of the mainframe's continued existence is as you say, combined with risk aversion to changing software that currently works, and a lack of people who understands how it even works to know how to change it. But the heart of the mainframe's failure to expand is IBM's reluctance to join the modern world in pricing and availability. There is no simple way to become a mainframe dev because there is no simple way to get access to modern zOS. There is an entry fee. And it's hard to be excited about anything they do to the silicon when you know that you don't just buy the system, you're charged for consumption as if it were a cloud device. So, nobody with a wallet wants to run anything other than the essentials there, hence the platform never grows.

by froh 2y ago

wolf550e 2y ago

The amount of throughput you can get out of AMD EPYC zen5 servers for the price of a basic mainframe is insane. Even if IBM wins in single core perf using absurd amount of cache and absurd cooling solution, the total rack throughput is definitely won by "commodity" hardware.

rbanffy 2y ago
Maybe, but then you need to engineer the 99.99999% uptime yourself. If it were actually cheaper, IBM wouldn’t be selling these machines so well.
- oldpersonintx 2y ago
  [dead]
- wolf550e 2y ago
  I don't think they are actually selling those machines so well. They have a captive legacy customer base, who else is buying those?
  - neverartful 2y ago
    From TFA: "Overall, Z is growing very healthily. LinuxONE is the fastest area of growth for us right now." However, he didn't elaborate or give any examples. If I were the interviewer, I would have followed it with: "Oh?! Can you provide some examples for the readers who believe that you only sell to captive audiences?"
    - rbanffy 2y ago
      If I had the need to ridiculously scale up a Linux workload, I’d immediately think LinuxONE or POWER. If I had the R&D budget for an on-prem VM hosting box, I’d seriously consider their smaller Express 4, which is not much pricier than a similarly capable x86 machine.
    - IanCutress 2y ago
      Because I've covered that in a previous video :) https://www.youtube.com/watch?v=ZVO55oxJ464 https://www.youtube.com/watch?v=ZVO55oxJ464
- Muromec 2y ago
  They are mostly selling to the captive audience who is 40 years deep into COBOL and can't pull out until it falls on top of them.
  - feurio 2y ago
    Well, you know what to do - just sell a system that runs COBOL on an x86 cluster or Kubernetes or whatever, and you'll make billions! Be sure to allocate me a bunch of shares for giving you the idea.
  - pjmlp 2y ago
    Many of those machines are running Java workloads, also COBOL isn't the only mainframe language, and the best thing in terms of security is that they don't use C as systems language, rather saner stuff with proper arrays, strings and bounds checking. That is why Unisys ClearPath MCP is still a thing, tracing back to its Burroughs 1961 heritage, security above all.
    - rbanffy 2y ago
      Java workloads might be easier to port away from but aren’t MCP machines x86-based nowadays? Unisys did a ton of work for Microsoft making itself obsolete by adding a lot to their secret multiprocessor stuff to Windows. It’s amazing how Microsoft convinced so many companies to shoot their feet.
      - pjmlp 2y ago
        They still use NEWP as systems language, there is no C stuff to exploit.
        rbanffy 2y ago
        I had a lot of trouble with the idiosyncratic ways of MCP, and I have no doubt Tron's villain was named after it.
  - rbanffy 2y ago
neverartful 2y ago
These comments always come up with every mainframe post. It's not only about performance. If it were it would be x86 or pSystems (AIX/POWER). The reason customers buy mainframes is RAS (reliabililty, availability, scalability). Notice that performance is not part of RAS.
- jiggawatts 2y ago
  You and the parent are both "missing the point", which is sadly not talked about by the manufacturer either (IBM). I used to work for Citrix, which is "software that turns Windows into a mainframe OS". Basically, you get remote thin terminals the same as you would with an IBM mainframe, but instead of showing you green text you get a Windows desktop. Citrix used to sell this as a "cost saving" solution that inevitably would cost 2-3x the same as traditional desktops. The real benefit for both IBM mainframes and Citrix is: latency. You can't avoid the speed of light, but centralising data and compute into "one box" or as close as you can get it (one rack, one data centre, etc...) provides enormous benefits to most kinds of applications. If you have some complex business workflow that needs to talk to dozens of tables in multiple logical databases, then having all of that unfold in a single mainframe will be faster than if it has to bounce around a network in a "modern" architecture. In real enterprise environments (i.e.: not a FAANG) any traffic that has to traverse between servers will typically use 10 Gbps NICs at best (not 100 Gbps!), have no topology optimisation of any kind, and flow through at a minimum one load balancer, one firewall, one router, and multiple switches. Within a mainframe you might have low double-digit microsecond latencies between processes or LPARs, across an enterprise network between services and independent servers its not unusual to get well over one millisecond -- one hundred times slower. This is why mainframes are still king for many orgs: They're the ultimate solution for dealing with speed-of-light delays. PS: I've seen multiple attempts to convert mainframe solutions to modern "racks of boxes" and it was hilarious to watch the architects be totally mystified as to why everything was running like slow treacle when on paper the total compute throughput was an order of magnitude higher than the original mainframe had. They neglected latency in their performance modelling, that's why!
  - le-mark 2y ago

graycat 2y ago

Virtual machine changes since CP67/CMS?

froh 2y ago
ah, a connoisseur... alas the last bottle of that was served in 1972 the current incarnation is z/VM, which started 2000. it is rumored to have one or two new features.

bitsandboots 2y ago

The heart of the mainframe success was being first to make a real OS and real forward compatibility. The heart of the mainframe's continued existence is as you say, combined with risk aversion to changing software that currently works, and a lack of people who understands how it even works to know how to change it. But the heart of the mainframe's failure to expand is IBM's reluctance to join the modern world in pricing and availability. There is no simple way to become a mainframe dev because there is no simple way to get access to modern zOS. There is an entry fee. And it's hard to be excited about anything they do to the silicon when you know that you don't just buy the system, you're charged for consumption as if it were a cloud device. So, nobody with a wallet wants to run anything other than the essentials there, hence the platform never grows.