Re: OT: The Geek defense

On Thu, 28 Feb 2008 19:19:34 +0000, tim wrote:

Sorry about that.

The stories about working all weekend reminded me of a couple of things...

One was the anxiety that accompanied a major production change. On one
occasion I designed a whole lot of changes designed to make the system run
faster, as there were response time problems. On paper they looked great,
and I even wrote and ran a small IMS simulator and it looked good there as
well. However when we stress tested it, it ran fast alright, until IMS
crashed. It lasted about 20 minutes between crashes. It turned out that
the increased intensity of multiprocessing brought out some latent bugs in
IMS and caused the crashes. Eventually IBM fixed the bugs and the changes
went in OK, but I was sweating that weekend.

Another time, I proposed massively increasing the number of streams in the
overnight batch run. The sequential IO in IMS Fastpath was very slow and
we needed the streams to run all the CPUs to capacity and get the run
finished as fast as possible. Again I had modeled the changes and I they
had been stress tested. However computer ops were making all sorts of
objections, for no obvious reason. One day the manager made the comment
that "You systems programmers have no idea what we go through out here. If
you spent a night out here you would really understand." So I went out to
the computer center and spent the night talking to the operators. A very
enjoyable experience, if tiring. The amazing thing was after that the
changes sailed through with no objections. Once they felt we understood
their problems they were happy to co-operate.

Tim
.