It has long been a hallmark of our profession to over-achieve. We prepared for 
Y2K so well that predicted chaos was averted. Even entertaining chaos was rare. 
😉

I was personally convinced that we would be 'OK', but I made one particular 
concession to the doomsday crowd. I collected a few hundred dollars' worth of 
$5 bills on the grounds that ATMs might be the only source of cash. Didn't want 
to have to pay $20 each for every little thing. I eventually spent them all at 
leisure.  

.
.
J.O.Skip Robinson
Southern California Edison Company
Electric Dragon Team Paddler 
SHARE MVS Program Co-Manager
323-715-0595 Mobile
626-543-6132 Office ⇐=== NEW
[email protected]

-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On Behalf Of 
Vernooij, Kees (ITOP NM) - KLM
Sent: Friday, January 3, 2020 6:43 AM
To: [email protected]
Subject: (External):Re: it was 20 years ago today

Correct. 
And then I see yesterday on a local news site an article with a suggestive 
title like: a lot of fuzz, but hardly any problems really occurred.

The article itself has a little more nuance, but it is still nice food for 
title hunters (useful if your business model exists of getting as much people 
as possible to generate advertisement hits).

Kees.

-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf 
Of Jeremy Nicoll
Sent: 03 January 2020 15:24
To: [email protected]
Subject: Re: it was 20 years ago today

On Fri, 3 Jan 2020, at 00:49, Joel C. Ewing wrote:

> The problem for us was not "how" to fix a single instance of the 
> problem, but finding "where" to fix an unknown number of instances of 
> the problem in 1000's of lines of in-house code and in associated data sets.

I think how complex this was depended a lot on how old a site's applications 
were.  It also depended on how long the 'tail' or archived data was.

Suppose you identified all the instances of a single date data column in a 
single current file that might be read and rewritten by umpteen programs.  If 
you changed all the programs you'd also need either to change the data in all 
the archived files as well, or make the program able to decide whether it was 
running in pre-change or post-change mode.

But you'd also need to change all the other programs that also read those old 
archive files.  And that might have knpck-on effects on other files that they 
manipulated.

While doing this, you also had to make sure that - if your change failed - you 
could back it out and create/recreate all the related files.

It's rapidly obvious that you can't change all old files in sync with a series 
of program changes and still allow all your old, or not-yet-changed programs to 
process the old files (because you changed those).

That's why the date-window approach got  used.  The as-yet-unchanged programs 
could contine to read all the archived data, while the updated programs could 
handle the old-format data more intelligently.

If I remember correctly, one of the changes that happened (to customer
TS&Cs) was that we no longer supported customers aged > 100.  I have no idea 
what they were meant to do with their money.

Where I worked (a UK bank), Y2K was a big deal.  A colossal amount of work was 
done in the two or so years beforehand, and on the night the computer centre 
was heavily staffed - not quite as many of us as on a normal day, but 
nevertheless lots.

We had by then run simulated workloads back and forth across the date change 
many times, as well as checking things like how end-of-financial/ tax 
year/calendendar year processing could be expected to go (at eg end of March 
2000, 5/6 April 2000, 31 Dec 2000) and I expect beyond that as eg programmes 
doing 2-year, 5-year etc historical reports and those doing forecasting that 
might not run until some months later also needed to be thought to be ok.


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