7 ms·

Why Do Mainframes Still Exist? What's Inside One? [video]

vb-8448 3y ago
One of the reason they still exist is that a software written and compiled in late 80s is still running in production environment unchanged since then. They also have some other cool features like "serverless", low operational overhead, decoupling between cpu and storage.
- shiroiuma 3y ago
  I thought the big thing was redundancy and correctness, like having 3 processors run every computation and voting, to make sure no one's bank balance is accidentally in error.
  - vb-8448 3y ago
    I don't think most of the programmers or managers knows about this, they just assume computation is right; and for sure the correctness check of the bank balance is done on the application level.
- guenthert 3y ago
  Well, if it were only to run software written in the 80s, an emulator would do (modern hardware compensating the inefficient execution many times over).
  - vb-8448 3y ago
    I'm not sure, but I guess under the hood IBM does some emulation to guarantee backward compatibility.
    - thequux 3y ago
      Largely no, actually; modern z/Architecture is a strict superset of the System/360 ISA from the 70's. Every instruction that accesses memory has the original 24-bit address version, a 32-bit version, and a 64-bit version that also uses 64-bit registers. Thus there's no emulation involved; at least, not that's visible to the OS (but who knows what the microcode is doing underneath)
  - Pet_Ant 3y ago
    > modern hardware compensating the inefficient execution many times over That's assuming volumes haven't changed. They had credit cards in 1980 but the volumes have gone up considerably. I'd also guess trading volumes and other financial products as well.
xattt 3y ago
What’s the deal with the microphone-in-face aesthetic of YouTube videos? Is there some sort of appeal other than showing off your gold-plated mic?
- emchammer 3y ago
  Keeping a cardioid or supercardioid mic close to your mouth reduces room reverberation in the audio which makes it listenable. The person in this video is using an RE20, a classic dynamic microphone widely used in radio broadcasting. In fact in this video it's a little further away than usual, so I think he is trying to play it down. As to the gold microphones that some YouTubers are practically making out with, they keep it so very close for the proximity effect which boosts the bass in their voice. The RE20 has a switch to approximate that effect without being so close, which sounds likely to be on in this video. The tacky gold plating on cheap microphones is not worth anything. The best microphones are grey or black, but you might see a little bit of the gold-plated condenser through the grille.
- Pet_Ant 3y ago
  Have you ever watch a podcast? It's the same, but they avoid the awkward shots by rarely looking into the camera.
hardware2win 3y ago
Arent mainframes good example of better technology that lost? It feels like world gave up on reliable hardware and started fixing it on software/multiple hw instances level
- Borg3 3y ago
  I think thats one of the reasons why Sun Microsystems disappeard. They HW was very reliable.
  - effie 3y ago
    Nope. They made great software, and not so good hardware. They went away because dot-com bubble burst and tech world cancelled orders of the hardware. Also, bad business decisions linking their success with sales of hardware, instead of support for software. > "Sun is responsible" for the problem, said a project manager at a large European bank that was affected by it. The manager spoke on condition of anonymity. "Their architecture was fundamentally flawed because there was no ECC checking on the cache memory. This is something you get in even the lowliest Intel processor that costs a few dollars," he said in an e-mail message. https://www.computerworld.com/article/2585204/sun-fixes-server-problem--but-controversy-persists.html https://www.computerworld.com/article/2585204/sun-fixes-serv...
- effie 3y ago
  Yep, it's a dinosaur concept nobody with tight budget wants to pay for, unless they already do and money is no object(big Fortune 500 companies).
- Brian_K_White 3y ago
  I'd say instead of good, it's what I call gold plating. Not in the cheap fake not real gold way but in the "sure a gold plated muffler would be better than an aluminum or zink plated one", but is ultimately not the best place to invest that much resource.
- lamontcg 3y ago
  > started fixing it on software/multiple hw instances level Really we just don't care about it. Things like ecommerce doesn't have the reliability requirements that finance can have. In some cases you can be losing a million dollars a minute, and screwing up can result in the SEC coming to your offices and arresting people. You can't just issue a refund or a gift card to fix the problems. And instead of dealing with the sharp edges of the CAP theorem you can just buy one big machine that never fails. It is the kind of decision you rationally make when eventual consistency means that you might wind up in prison.
qwerty456127 3y ago
Mainframes still existing don't seem the most weird part. Who doesn't want an ultra-reliable computer after all? Why not use them if your business is so huge and important that you can afford them? To me nuclear power plants controlled by Windows computers seem much more crazy. The thing which actually seems weird about mainframes is them still using EBCDIC.
- neverartful 3y ago
  That's a function of the software and not the hardware. If you run Linux bare metal LPAR (no one does) or as a z/VM guest you'll have ASCII.
- nuc1e0n 3y ago
  ASCII is still used by older systems also. A modern mainframe won't be using only EBCDIC. If regulations change then system upgrades will be needed to cope with that changing environment. But that involves spending money to do them of course. EBCDIC exists for compatibility with systems much older than ASCII. I don't like EBCDIC much, but it has valid reasons to exist. It's not like it would be a good choice for new development, nor would even big blue advocate something not Unicode related now I'd imagine. Times change and we need to change with the times.
PebblesHD 3y ago
I think I’ve made this comment before, but there really are some jobs that monolithic big iron does better, particularly in banking where you need guaranteed exactly-once delivery scaled massively to support transaction processing, where re-creating the system with a modern architecture would need multiple times the infrastructure and maintenance. That combined with existing COBOL/Natural codebases that work pretty reliably and are regulator approved gives mainframes an element of inertia that I suspect will outlive even me.
- effie 3y ago
  This is what IBM and people living off mainframes tell the world all day long, but I think you'll have trouble showing that mainframe's job can't be replaced by a few hi-end x86 servers under cost. Inertia, regulators, and company having lots of money to the point they don't care (banks...) explains mainframes. They do the job well, so why bother replacing them if you don't care that they cost more.
  - freedomben 3y ago
    > This is what IBM and people living off mainframes tell the world all day long, but I think you'll have trouble showing that mainframe's job can't be replaced by a few hi-end x86 servers under cost. It's been tried many times before, and it never works out. Whether it's system complexity that can't be replicated, or woes from floating point imprecision, it's a hell of a lot harder than people who haven't dug into it think.
    - unmole 3y ago
      > It's been tried many times before, and it never works out. Seems to work just fine for Indian banks and the Income Tax Department.
      - freedomben 3y ago
        Is the story published anywhere that you know of? I'd be interested in reading more about this
effie 3y ago
I can't stand Dave's garage. There's no garage - he's a Microsoft millionaire who became a youtuber bragging about his empty golden tech life escapades fueled by the well-paying position as a programmer at Microsoft in the past. Now he made a shallow acolyte video which seems like it should have been a paid marketing by the IBM mainframe division. I hope he got payed well, otherwise Dave is even more self-unaware that I thought. I get this is what Linus Tech Tips would do for a living, but really, a senior programmer with gobs of money is doing this superficial reporting on a what IBM told him on his trip there??? Seriously, this video (and YT comments it has) is a naive uncritical sucker reverberating most of the standard phrases from the mainframe sphere, although admittedly, with nice high-def shots of the machine components. I expected more serious adult commentary, not a teenage boy fan ravings. Mainframes by IBM are a niche expensive product that is an interesting concept and history, but it is not an "amazing machine" to be put up today. There is no perspective for most young people working on mainframes, they will be phased out eventually. It's a solid product for the captured audience, which is like 2 banks and card payment processors, but that's it. "Woo, they don't rely on ECC, they have multiple independent modules, because cosmic radiation, so cool" Get real, this is not an important problem, ECC works already, and good software has to account for occassional HW errors anyway.
- theandrewbailey 3y ago
  Mainframes have their uses, and I haven't heard of anyone pushing them outside of financial applications, where mainframes don't offer much value. As for being eventually phased out, so will everything else, even x86 and ARM. You don't have to like Dave, his "garage", his channel, or his previous employers, but lots of people find his videos interesting.
  - effie 3y ago
    I agree. But that's a problem. People are easy to impress these days and don't think through what the message actually is.
- tambourine_man 3y ago
  You make good points but with excessive vitriol.
nuc1e0n 3y ago
Dave says he hopes that they don't tip over the mainframes that often. I hope they do frequently subject them to such testing. In a world with hurricanes, earthquakes and other disasters it can be really important that the mainframe just keeps on trucking. The sysadmins might not be around to babysit them all the time, such as during flooding.

One of the reason they still exist is that a software written and compiled in late 80s is still running in production environment unchanged since then. They also have some other cool features like "serverless", low operational overhead, decoupling between cpu and storage.

shiroiuma 3y ago
I thought the big thing was redundancy and correctness, like having 3 processors run every computation and voting, to make sure no one's bank balance is accidentally in error.
- vb-8448 3y ago
  I don't think most of the programmers or managers knows about this, they just assume computation is right; and for sure the correctness check of the bank balance is done on the application level.
guenthert 3y ago
Well, if it were only to run software written in the 80s, an emulator would do (modern hardware compensating the inefficient execution many times over).
- vb-8448 3y ago
  I'm not sure, but I guess under the hood IBM does some emulation to guarantee backward compatibility.
  - thequux 3y ago
    Largely no, actually; modern z/Architecture is a strict superset of the System/360 ISA from the 70's. Every instruction that accesses memory has the original 24-bit address version, a 32-bit version, and a 64-bit version that also uses 64-bit registers. Thus there's no emulation involved; at least, not that's visible to the OS (but who knows what the microcode is doing underneath)
- Pet_Ant 3y ago
  > modern hardware compensating the inefficient execution many times over That's assuming volumes haven't changed. They had credit cards in 1980 but the volumes have gone up considerably. I'd also guess trading volumes and other financial products as well.

xattt 3y ago

What’s the deal with the microphone-in-face aesthetic of YouTube videos? Is there some sort of appeal other than showing off your gold-plated mic?

emchammer 3y ago
Keeping a cardioid or supercardioid mic close to your mouth reduces room reverberation in the audio which makes it listenable. The person in this video is using an RE20, a classic dynamic microphone widely used in radio broadcasting. In fact in this video it's a little further away than usual, so I think he is trying to play it down. As to the gold microphones that some YouTubers are practically making out with, they keep it so very close for the proximity effect which boosts the bass in their voice. The RE20 has a switch to approximate that effect without being so close, which sounds likely to be on in this video. The tacky gold plating on cheap microphones is not worth anything. The best microphones are grey or black, but you might see a little bit of the gold-plated condenser through the grille.
Pet_Ant 3y ago
Have you ever watch a podcast? It's the same, but they avoid the awkward shots by rarely looking into the camera.

hardware2win 3y ago

Arent mainframes good example of better technology that lost? It feels like world gave up on reliable hardware and started fixing it on software/multiple hw instances level

Borg3 3y ago
I think thats one of the reasons why Sun Microsystems disappeard. They HW was very reliable.
- effie 3y ago
  Nope. They made great software, and not so good hardware. They went away because dot-com bubble burst and tech world cancelled orders of the hardware. Also, bad business decisions linking their success with sales of hardware, instead of support for software. > "Sun is responsible" for the problem, said a project manager at a large European bank that was affected by it. The manager spoke on condition of anonymity. "Their architecture was fundamentally flawed because there was no ECC checking on the cache memory. This is something you get in even the lowliest Intel processor that costs a few dollars," he said in an e-mail message. https://www.computerworld.com/article/2585204/sun-fixes-server-problem--but-controversy-persists.html https://www.computerworld.com/article/2585204/sun-fixes-serv...
effie 3y ago
Yep, it's a dinosaur concept nobody with tight budget wants to pay for, unless they already do and money is no object(big Fortune 500 companies).
Brian_K_White 3y ago
I'd say instead of good, it's what I call gold plating. Not in the cheap fake not real gold way but in the "sure a gold plated muffler would be better than an aluminum or zink plated one", but is ultimately not the best place to invest that much resource.
lamontcg 3y ago
> started fixing it on software/multiple hw instances level Really we just don't care about it. Things like ecommerce doesn't have the reliability requirements that finance can have. In some cases you can be losing a million dollars a minute, and screwing up can result in the SEC coming to your offices and arresting people. You can't just issue a refund or a gift card to fix the problems. And instead of dealing with the sharp edges of the CAP theorem you can just buy one big machine that never fails. It is the kind of decision you rationally make when eventual consistency means that you might wind up in prison.

qwerty456127 3y ago

Mainframes still existing don't seem the most weird part. Who doesn't want an ultra-reliable computer after all? Why not use them if your business is so huge and important that you can afford them? To me nuclear power plants controlled by Windows computers seem much more crazy. The thing which actually seems weird about mainframes is them still using EBCDIC.

neverartful 3y ago
That's a function of the software and not the hardware. If you run Linux bare metal LPAR (no one does) or as a z/VM guest you'll have ASCII.
nuc1e0n 3y ago
ASCII is still used by older systems also. A modern mainframe won't be using only EBCDIC. If regulations change then system upgrades will be needed to cope with that changing environment. But that involves spending money to do them of course. EBCDIC exists for compatibility with systems much older than ASCII. I don't like EBCDIC much, but it has valid reasons to exist. It's not like it would be a good choice for new development, nor would even big blue advocate something not Unicode related now I'd imagine. Times change and we need to change with the times.

PebblesHD 3y ago

I think I’ve made this comment before, but there really are some jobs that monolithic big iron does better, particularly in banking where you need guaranteed exactly-once delivery scaled massively to support transaction processing, where re-creating the system with a modern architecture would need multiple times the infrastructure and maintenance. That combined with existing COBOL/Natural codebases that work pretty reliably and are regulator approved gives mainframes an element of inertia that I suspect will outlive even me.

effie 3y ago
This is what IBM and people living off mainframes tell the world all day long, but I think you'll have trouble showing that mainframe's job can't be replaced by a few hi-end x86 servers under cost. Inertia, regulators, and company having lots of money to the point they don't care (banks...) explains mainframes. They do the job well, so why bother replacing them if you don't care that they cost more.
- freedomben 3y ago
  > This is what IBM and people living off mainframes tell the world all day long, but I think you'll have trouble showing that mainframe's job can't be replaced by a few hi-end x86 servers under cost. It's been tried many times before, and it never works out. Whether it's system complexity that can't be replicated, or woes from floating point imprecision, it's a hell of a lot harder than people who haven't dug into it think.
  - unmole 3y ago
    > It's been tried many times before, and it never works out. Seems to work just fine for Indian banks and the Income Tax Department.
    - freedomben 3y ago
      Is the story published anywhere that you know of? I'd be interested in reading more about this

effie 3y ago

I can't stand Dave's garage. There's no garage - he's a Microsoft millionaire who became a youtuber bragging about his empty golden tech life escapades fueled by the well-paying position as a programmer at Microsoft in the past. Now he made a shallow acolyte video which seems like it should have been a paid marketing by the IBM mainframe division. I hope he got payed well, otherwise Dave is even more self-unaware that I thought. I get this is what Linus Tech Tips would do for a living, but really, a senior programmer with gobs of money is doing this superficial reporting on a what IBM told him on his trip there??? Seriously, this video (and YT comments it has) is a naive uncritical sucker reverberating most of the standard phrases from the mainframe sphere, although admittedly, with nice high-def shots of the machine components. I expected more serious adult commentary, not a teenage boy fan ravings. Mainframes by IBM are a niche expensive product that is an interesting concept and history, but it is not an "amazing machine" to be put up today. There is no perspective for most young people working on mainframes, they will be phased out eventually. It's a solid product for the captured audience, which is like 2 banks and card payment processors, but that's it. "Woo, they don't rely on ECC, they have multiple independent modules, because cosmic radiation, so cool" Get real, this is not an important problem, ECC works already, and good software has to account for occassional HW errors anyway.

theandrewbailey 3y ago
Mainframes have their uses, and I haven't heard of anyone pushing them outside of financial applications, where mainframes don't offer much value. As for being eventually phased out, so will everything else, even x86 and ARM. You don't have to like Dave, his "garage", his channel, or his previous employers, but lots of people find his videos interesting.
- effie 3y ago
  I agree. But that's a problem. People are easy to impress these days and don't think through what the message actually is.
tambourine_man 3y ago
You make good points but with excessive vitriol.

nuc1e0n 3y ago

Dave says he hopes that they don't tip over the mainframes that often. I hope they do frequently subject them to such testing. In a world with hurricanes, earthquakes and other disasters it can be really important that the mainframe just keeps on trucking. The sysadmins might not be around to babysit them all the time, such as during flooding.