4 ms·

Not as long as IBM continues to make mainframes and components, which they do. If you were unable to source replacement hardware to keep it running indefinitel

Not as long as IBM continues to make mainframes and components, which they do. If you were unable to source replacement hardware to keep it running indefinitely, then yes, but until then it's better to keep paying a couple million a year to keep your business running as-is than to spend hundreds of millions to effectively rebuild the entire infrastructure from the ground up in parallel to the running infrastructure. Remember that these are large, public businesses. Explaining to shareholders that profits are going to take a noticeable hit for years because of IT investment that isn't strictly necessary is effectively a non-starter.

benj111 7y ago
"rebuild the entire infrastructure from the ground up in parallel" I wasn't thinking that. I was thinking more like when you add a new feature, fit it into an API that is portable. Or add a translation layer so the feature can be written how you would like system to be in the future, but it works on your hardware today.
- wahern 7y ago
  Everybody attempts this. But the problem is that the ground keeps moving under your feet. Your portable interfaces become irrelevant as software systems evolve. XML gives way to JSON, etc. Eventually it costs just as much in time and effort to interoperate with your 10-20 year old "portable" interface as it would to interface with the mainframe directly, which was already established to have been too costly to bother. So now you have two problems, not just one.
  - benj111 7y ago
    Possibly. First I'd say that xml doesn't become 'wrong' when json came about. If that 1950s data format works for you, and you don't see advantages to moving, then fine stay with it. 2nd I'd say theres a half life of best practise. Over the 10 20 year tome frame, id expect some of what you were doing is going to become outdated yes, on the same way some of your knowledge over your career will become outdated, or the phone I your pocket will, you wouldn't use that as an argument against education, or buying that phone. Btw, if its as costly to deal with the interface as with the mainframe directly, that's a win. The interface can move off the mainframe to somewhere cheaper/better.
    - wahern 7y ago
      > First I'd say that xml doesn't become 'wrong' when json came about. It doesn't become wrong, it just evolves into another dead-end. The 3270 is an interface, too, but the reason everybody suggests replacing it or augmenting it is precisely because the spartan tooling and mindshare makes it expensive. As XML recedes into history it is likewise becoming more expensive as an interface. I chose XML vs JSON because I figured it was a transition everybody was somewhat familiar with. And younger programmers have an almost visceral dislike of XML, which I thought might help get the point across--that an interface someone once thought (and probably still thinks) would help ease future interoperability becomes a reason or excuse for future programmers to avoid that integration. > Btw, if its as costly to deal with the interface as with the mainframe directly, that's a win. I think the problem is that you don't really know if it's as costly. The error bars on that sort of risk assessment are huge because our industry sucks at accurately predicting migration costs. And it sucks because complex software systems are intrinsically unique. Commercial solutions that claim to be able to capture and control all those dimensions of complexity tend to be sold by vendors with names like IBM and Oracle. Such vendors also pioneered interfaces like SQL, which is both a soaring achievement in terms of capturing complexity behind a beautiful interface while also falling epically short of what's needed to actually reduce long-term integration costs.

benj111 7y ago

"rebuild the entire infrastructure from the ground up in parallel" I wasn't thinking that. I was thinking more like when you add a new feature, fit it into an API that is portable. Or add a translation layer so the feature can be written how you would like system to be in the future, but it works on your hardware today.

wahern 7y ago
Everybody attempts this. But the problem is that the ground keeps moving under your feet. Your portable interfaces become irrelevant as software systems evolve. XML gives way to JSON, etc. Eventually it costs just as much in time and effort to interoperate with your 10-20 year old "portable" interface as it would to interface with the mainframe directly, which was already established to have been too costly to bother. So now you have two problems, not just one.
- benj111 7y ago
  Possibly. First I'd say that xml doesn't become 'wrong' when json came about. If that 1950s data format works for you, and you don't see advantages to moving, then fine stay with it. 2nd I'd say theres a half life of best practise. Over the 10 20 year tome frame, id expect some of what you were doing is going to become outdated yes, on the same way some of your knowledge over your career will become outdated, or the phone I your pocket will, you wouldn't use that as an argument against education, or buying that phone. Btw, if its as costly to deal with the interface as with the mainframe directly, that's a win. The interface can move off the mainframe to somewhere cheaper/better.
  - wahern 7y ago
    > First I'd say that xml doesn't become 'wrong' when json came about. It doesn't become wrong, it just evolves into another dead-end. The 3270 is an interface, too, but the reason everybody suggests replacing it or augmenting it is precisely because the spartan tooling and mindshare makes it expensive. As XML recedes into history it is likewise becoming more expensive as an interface. I chose XML vs JSON because I figured it was a transition everybody was somewhat familiar with. And younger programmers have an almost visceral dislike of XML, which I thought might help get the point across--that an interface someone once thought (and probably still thinks) would help ease future interoperability becomes a reason or excuse for future programmers to avoid that integration. > Btw, if its as costly to deal with the interface as with the mainframe directly, that's a win. I think the problem is that you don't really know if it's as costly. The error bars on that sort of risk assessment are huge because our industry sucks at accurately predicting migration costs. And it sucks because complex software systems are intrinsically unique. Commercial solutions that claim to be able to capture and control all those dimensions of complexity tend to be sold by vendors with names like IBM and Oracle. Such vendors also pioneered interfaces like SQL, which is both a soaring achievement in terms of capturing complexity behind a beautiful interface while also falling epically short of what's needed to actually reduce long-term integration costs.