3 ms·

A million tx/hour is only few hundred/second. I've done call routing, including full ACID balance updates, at over 10x that volume, on commodity hardware and so

A million tx/hour is only few hundred/second. I've done call routing, including full ACID balance updates, at over 10x that volume, on commodity hardware and software. Why is this a huge challenge for anyone? I get the feeling it's mostly legacy plus scenarios where the rigor IBM applies is valuable and you go along with whatever they suggest.

rdtsc 11y ago
It depends on the size/type of the transaction of course... A financial transaction might not be exactly comparable with a call setup.
- StillBored 11y ago
  IBM doesn't have magic pixie dust in zseries mainframes. I had one, and trust me, you can beat it in every single metric with commodity hardware. What makes them "faster" in many cases is that the decades old apps were written by people "with a clue" and they run pretty much on the hardware. I've had a joke going for a few years, that websphere was created to cause efforts to port off the mainframe to fail. AKA its pretty much impossible to take something running in ztpf, rewrite it in java and plunk it on a EC2 instance and have a hopes chance in hell of making it work without spending more than the next two decades of mainframe maintenance costs in monthly amazon bills. That doesn't mean you can't rewrite it in C++ on a DL580 with an attached Flash840 and leave the mainframe in the dust if you have competent programmers.
  - jussij 11y ago
    > you can beat it in every single metric with commodity hardware. The zSeries selling point is not the hardware, but the reliability (which is in fact the hardware). The z in that series stands for zero down time and they are not selling hardware, but close to 100% reliability. Now in reality, no one can guarantee zero down time, but IBM does in fact guarantee 5 nines (99.999%) and 6 nines (99.9999%) up time and that guarantee costs money. You certainly can't get those sort of up-time numbers using nothing but commodity hardware.
- MichaelGG 11y ago
  Sure. But I doubt it's more than an order of magnitude more difficult. Each call needs routing info (lookups over a hundred million rows a few times). It also generates a CDR, which, in some systems, means a full transaction (insert a row, update a balance). Another way to view this: since mainframe workloads have existed for a long time, if their performance was way beyond what you can still accomplish with commodity hardware, then we should see tech companies utterly flocking to these systems. We should see IBM selling their chips all over (after all, why wouldn't Microsoft want to get in on the action?). No one wants to deal with huge fleets of servers. If they could just give IBM some money and be done, they'd do that, no? But instead it's mostly used for older, risk adverse, applications. So while I've no doubt they end up delivering solid systems, I'm skeptical that the scale is more massive than people are used to.

rdtsc 11y ago

It depends on the size/type of the transaction of course... A financial transaction might not be exactly comparable with a call setup.

StillBored 11y ago
IBM doesn't have magic pixie dust in zseries mainframes. I had one, and trust me, you can beat it in every single metric with commodity hardware. What makes them "faster" in many cases is that the decades old apps were written by people "with a clue" and they run pretty much on the hardware. I've had a joke going for a few years, that websphere was created to cause efforts to port off the mainframe to fail. AKA its pretty much impossible to take something running in ztpf, rewrite it in java and plunk it on a EC2 instance and have a hopes chance in hell of making it work without spending more than the next two decades of mainframe maintenance costs in monthly amazon bills. That doesn't mean you can't rewrite it in C++ on a DL580 with an attached Flash840 and leave the mainframe in the dust if you have competent programmers.
- jussij 11y ago
  > you can beat it in every single metric with commodity hardware. The zSeries selling point is not the hardware, but the reliability (which is in fact the hardware). The z in that series stands for zero down time and they are not selling hardware, but close to 100% reliability. Now in reality, no one can guarantee zero down time, but IBM does in fact guarantee 5 nines (99.999%) and 6 nines (99.9999%) up time and that guarantee costs money. You certainly can't get those sort of up-time numbers using nothing but commodity hardware.
MichaelGG 11y ago
Sure. But I doubt it's more than an order of magnitude more difficult. Each call needs routing info (lookups over a hundred million rows a few times). It also generates a CDR, which, in some systems, means a full transaction (insert a row, update a balance). Another way to view this: since mainframe workloads have existed for a long time, if their performance was way beyond what you can still accomplish with commodity hardware, then we should see tech companies utterly flocking to these systems. We should see IBM selling their chips all over (after all, why wouldn't Microsoft want to get in on the action?). No one wants to deal with huge fleets of servers. If they could just give IBM some money and be done, they'd do that, no? But instead it's mostly used for older, risk adverse, applications. So while I've no doubt they end up delivering solid systems, I'm skeptical that the scale is more massive than people are used to.