On Sat, Nov 27, 2010 at 7:50 PM, David Masover <ninja / slaphack.com> wrote:
>
> I suppose I expected people to be developing modern Linux apps that just
> happen to compile on that hardware.

Linux is usually not the OS the vendor supports. Keep in mind, a day
of lost productivity on this kind of systems means losses in the
millions of dollars area.

> But then, corporations the size of Google tend to store their information
> distributed on cheap PC hardware.

If they were incorporated where there was such a thing as "cheap PC
hardware". Google is a young corporation, even in IT. And they need
loads of custom code to make their search engine and datacenters
perform and scale, too.

>> And mainframes with vector CPUs are ideal for all sorts of simulations
>> engineers have to do (like aerodynamics), or weather research.
>
> When you say "ideal", do you mean they actually beat out the cluster of
> commodity hardware I could buy for the same price?

Sure, if you can shell out for about 14 000 Xeon CPUs and 7 000 Tesla
GPGPUs (Source: http://en.wikipedia.org/wiki/Tianhe-I ).

> All three of which suggest to me that in many cases, an actual greenfield
> project would be worth it. IIRC, there was a change to the California minimum
> wage that would take 6 months to implement and 9 months to revert because it
> was written in COBOL -- but could the same team really write a new payroll
> system in 15 months? Maybe, but doubtful.

So, you'd bet the corporation on the size of Exxon Mobile, Johnson &
Johnson, General Electric and similar, just because you *think* it is
easier to do changes 40 years later in an unproven, unused, upstart
language?

The clocks in the sort of shops that still run mainframes tick very
different from what you or I are used to.

> But it's still absurdly wasteful. A rewrite would pay for itself with only a
> few minor changes that'd be trivial in a sane system, but major year-long
> projects with the legacy system.

If the rewrite would pay for itself in the short term, then why hasn't
it been done?

-- 
Phillip Gawlowski

Though the folk I have met,
(Ah, how soon!) they forget
When I've moved on to some other place,
There may be one or two,
When I've played and passed through,
Who'll remember my song or my face.