Someone asked me why did they get the error message "The service is unavailable"? when they try to access services from certain websites, e.g. the electronic payslip service like the above example.
I think most of layman nowadays could have answered "oh, there are many web users trying to access the same service at the same time, thus the server becomes tired and it goes down".
Sounds true, isn't it?
But, my college students would argue back "...computers are not human being, sir. Shouldn't they free from tiredness and boresome?"
Hmm, that is true as well.
So, what happens actually?
While computers do not feel tired, their capacity is restricted to their software and hardware limits. If you push it to the limit, it will eventually stop responding.
"But how come Gmail almost doesn't have that problem?
This mind-provoking question is interesting.
"Does that mean Google have unlimited resources of hardware and software capacity?"
Well, I think that is partially true.
While hardware and software are critical to the "availability" aspect of a web service, the creativity of the web application developers also contribute to the overall system performance.
I am not a civil servant and therefore not directly affected by this kind of problem. But I could imagine how disappointing it is when somebody who badly need a service being denied an assistance because of technical problem. Hopefully the developer could brainstorm more ideas on overcoming congested service requests problem like this.
