Hi,
Here's a little performance calculation, which I do because: (1) I think
it's better than nothing for assessing the possible impact of the new
page and (2) it's fun (for me).
If there are 2 million hits a day, that means 2,000,000 / 1440 = 138.89
hits per second. Suppose z% of the traffic is for the old/new page, that
it takes D0 secs of cpu time to process the old page and D1 secs on the
average to process the new. Let D1-D0 = delta. Then the additional CPU
utilization due to using the new page is
U(delta) = delta * 138.89 * z / 100.
For laughs, suppose delta = 0.005 and z = 40. Then U(delta) = 0.005 *
55.556 = 0.28
so this means that 28% additional CPU time is being consumed. The delta
is made up: if you don't like it, pick your own or do a measurement :-).
What does this mean? Suppose with the old page the cpu is busy 60% of the
time, processing all traffic. With the new page, it will be busy 88% of
the time. If driving the CPU utilization this high doesn't bother you,
consider the effect on average CPU response time.
Simplistically, R = S / (1 - U), where R is average response time and S
is average service time. Now let S0 be the average CPU service time for a
request with the old page on the site and S1 when the new page is on the
site. U0 = 0.60, U1 = 0.88, so R0 = S0 * 2.5 and R1 = 8.33 * S1. So, if
the CPU is busy 60% of the time with the old page, using the new page
(with the off the wall assumptions I've made) cause the CPU part of
response time to increase by a factor of between 3 and 4!
For what it's worth, a lot of computing systems have been designed using
these kinds of calculations: maybe that's why they're sometimes called
"back of the envelope calculations".
I enjoyed this. I hope you did too. It might even be useful in the
future.
Roy
--
Roy Wilson
E-mail: [EMAIL PROTECTED]
>>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<
On 11/11/00, 2:45:09 PM, Nick Bauman <[EMAIL PROTECTED]> wrote regarding
Re: [OPINION] - New Jakarta Website:
> On Fri, 10 Nov 2000, Jon Stevens wrote:
> > Also, you need to realize that *.apache.org gets somewhere around 2
million
> > hits/day. Adding a lot of images (even small ones) to the website is a
> > _really_ bad idea. The more you can do with just nice text layout, the
> > better.
> For software developers, systems integrators; those of us in the trenches
> - less is more in website design. The artisitry on that demo page is
> really really great. But I believe Jakarta would be better served if this
> were more a study in user interface design than graphic design.
> > Another thing about the design that you posted, it wastes a HUGE amount
of
> > white space. You also need to remember that people often print these
pages
> > (don't ask me why!) and you should account for that by not wasting white
> > space.
> Once again, good graphic design != good user interface design. I agree
> with Jon.
> > -jon
> >
> >
> --
> Nicolaus Bauman
> Software Engineer
> Simplexity Systems
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