Why bad design sucks! - Part I

There are many areas of computing that have been let down by poor design.

Actually that may be a little harsh.

However, poor assumptions have definitely led to numerous designs that in hindsight could be considered questionable at best. These decisions have in turn led to systems that have suffered due to higher than anticipated volumes or longer than expected life spans.

A few examples that come to mind are:-

The millennium bug. Everyone knows this story. Developers designed systems in the 60s, 70s and 80s with 6 character dates ie DDMMYY or MMDDYY. The assumption being that storage is expensive and this system won't be around in 20 or 30 years. Well we all know how much effort was involved ensuring that airplanes never fell out of the sky in the late 90's, not to mention the contract rates for COBOL programmers that went with it. So I guess the lesson learned here is short sightedness.

http://www.trademe.co.nz/. Another example I heard about was for a very popular auction trading site here in New Zealand. The founders at a Microsoft TechEd conference a few years ago talked candidly about the early days of the business. They were describing growth of the business and unexpected challenges for the fledgling company.

The site was adding customers at a nice steady state when one day the system stopped working. No more new customers could be added.

They were a little concerned at first. After all they had just added their 32767th customer.

The issue was that in the early versions of their database they hadn't considered the domain of this particular field to carefully. i.e. the size. They had reached the limit for the integer field type on their platform. Now that the site is the most successful site in New Zealand and has made the creator a multi-millionaire, I am sure they have used at a minimum a long integer. The lesson learned here would be factor your wildest assumptions into your database designs.

www.Virtualrugby.co.nz. A sports predictions site here in NZ that has just rebranded again with another sponsor but suffered the ignominy of poor application performance and a whole host of players unable to access the site. On one occasion I was advised that the server was unable to make a connection because the limit of 111 connections had been reached. This is for a site that had over 100,000 active participants the previous year. I will go as far as suggesting the infrastructure suppliers arrangement may have changed as a result of the sponsorship change. Hopefully they'll get it sorted.

The lesson learned here. Never underestimate your audience and your processing peaks. Most of all ensure that your test systems have a reasonable subset of data to stress a mass participant application. Three guys in a room pressing the submit button as often as possible is not load/stress testing.

IPv6. Another in a long line of bad designs, or is it? It is alleged that we are to run out of IP addresses in the next few years. Some claim that this is the millennium bug of the 2000's. If it is and given the age of computing in general, we might have a few more yet. Sounds not too different to the 100 year storm scenario that happens every 4 years in these days of global warming.

I guess this one could have also been avoided but the caveat once again was when IP addressing got going the internet was quite young and connected devices were at a far lower number than they are today. Lesson earned! What do you think?

......

With all these though, IMHO it was human expectations that were at fault or shortcuts being taken to save a few bytes here or there. My advice to all application developers is to ensure that all your applications have database fields that are capable of supporting data sets beyond your wildest dreams. And to ensure that your application architecture is fit for purpose.

Bad design really does suck. Ask your end user(s).

Thanks for reading.
Lee.

p.s. I titled this Part I as I guess that now I have finally got this off my chest there will be other scenarios out there that will jump out shouting - BLOGGERTUNITY. Actually, one has just emerged but I will save that for another day.