December 03, 2004, 12:40 PM —
As I write this, there is a barely audible, irregular thumping noise
emanating from a dusty 386 PC in the corner of the room. I fear a system
failure is on the way.
The noise reminds me of a recent echo cardiograph I undertook in which
the full extent of my advanced addiction to caffeine was transformed
into sound. Thumping sounds caused by palpitations emanating from the
most important muscle I possess. I no longer drink coffee by the way.
If the noises from the PC in the corner get any louder, I can think of a
number of people who work with me who may find themselves experiencing
stress - rather then caffeine induced - palpitations. You see, that
dusty PC in the corner is running a system last touched about seven
years ago. I kid you not. Seven years ago. It has given tireless, 24/7
service during those years with only occasional weeding, mulching and
the odd tender loving warm boot from tender, loving hands.
Sure we have backups. Weekly backups. We even have a machine in hot
backup mode ready to take its place if it goes belly up. Despite all
this, we are still nervous. Nervous because the system has not been
touched in years. Nervous that a number of its hardware and software
components are now antiques in IT terms. Nervous that while some of the
system was built in-house, some of it was outsourced and the people
responsible for its development have long since disappeared to find
themselves in the jungles of South America or snowboarding their way
around the USA.
We are nervous because we know in our hearts and souls, that under that
irregular thumping noise, lies a ball of tightly integrated software
applications.
For 'tightly integrated' in the above sentence, feel free to read 'ball of mud'. Unless you are extremely lucky, you have some balls of mud in your sphere of influence too. Can you think of any systems you know that you are afraid to touch? Systems that have become so tightly
knotted over the years that no one human brain understands it all both
at a conceptual and detail level? I thought so.
Now. Given that balls of mud are the harsh reality of many IT systems
and given that tight integration was the catalyst for creating them,
isn't it odd that the phrase 'tightly integrated' still sounds so
appealing? I have seen many a C-level executive nod approvingly as the
phrase 'tightly integrated' drops from the lips of the system vendor or
the system integrator. Tight is good.
Actually, tight is almost always bad.
To most business people, 'integration' means process integration. That
is, some applications are tightly integrated if they work as one to
perform some business function. It is a very unfortunate fact of life
that the quickest and cheapest way to get started with process
integration is by means of spot-welding systems together. This so called
point-to-point integration accounts for most of the world's "tight
integration" code developed by system integrators.
The downside of tight integration can be severe. First, the costs of
modifying the point-to-point integrations can be significant. With the
inevitability of change, this is more than just of mere academic
interest. Indeed, I have known systems where the point-to-point
integration code had to be redone *from scratch* after an
innocuous-sounding change request from the business managers.
Second, and perhaps most significant in these days of high application
counts, tight integration does not scale. By that I mean, as the number
of point-to-point integrations grows, the number of "spot welds"
increases exponentially. I'll leave it to your powers of deduction to
conclude what happens to the dollar cost!
So, tight integration sounds good but burns a hole in your wallet. What
is the alternative? Here things get interesting. The buzz phrase is
'loose coupling' achieved by means of middleware.
Loose coupling comes in a number of flavors - some of which do not
address the fundamental problems of tight integration at all.
