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View Full Version : How the Internet works, part XIXCLVIX



Jeff Root
2011-Nov-21, 03:51 PM
When I go to http://www.ubuntu.com/ after the page appears to
be finished loading and displaying, the modem lights show data
being transferred and the status line continuously cycles:

Done
Connecting to www.ubuntu.com...
Connected to www.ubuntu.com...
Waiting for www.ubuntu.com...
Transferring data from www.ubuntu.com...

with the last four lines repeating a few times before saying
"Done" again, on a 14-second neverending cycle.

Any idea what is being downloaded, and why it repeats?

When something is pushed at me from a website like this, is
the website actually transmitting the data over and over and
over again, or is some innocent intermediary local to me doing
all the work?

-- Jeff, in Minneapolis

HenrikOlsen
2011-Nov-21, 04:12 PM
That page has lots of javascript, I'd expect it to be your browser which keeps pulling ads to present to you.

Jeff Root
2011-Nov-21, 04:43 PM
What do you mean by "ads" in this case?

So, if they put a script in the webpage, the browser gets blamed
for "pulling" the ads, eh?

The page looks relatively simple, with no animation of any kind.
I expect that you did note that the downloading stuff is all from
that same website.

I don't have any kind of ad-blocking thingy, although I did tell
Firefox to "Block pop-up windows" -- whatever that means.

-- Jeff, in Minneapolis

Strange
2011-Nov-21, 04:52 PM
There is an animated graphic on that page. It may be that after it has finished downloading the page that you can see, it is still downloading the other images to be displayed.

Jeff Root
2011-Nov-21, 05:18 PM
The regular 14-second endless repetition tells me that the
same things are being downloaded repeatedly. Is the animated
graphic the large image, to the right of the headline "Hey, good
looking!" ?

When I right-click on the image (or probably any image) and
select "View Image Info", at the bottom of the list of images are
a bunch that are greyed-out. (Or *were* greyed out the first
time I did it.) They are not displayed on the page, but are icons
for standard controls: Play / Pause, etc.

I don't have Flash Player installed because it wasn't on the
Ubuntu install disk, and it is a humongous download for the
64-bit version. (I downloaded the 32-bit version, but currently
I'm using the 64-bit OS.) Most web pages show a notice that
Flash Player needs to be updated. Maybe this page does
nothing. Except continually download those files...

-- Jeff, in Minneapolis

Strange
2011-Nov-21, 05:35 PM
It displays 4 images on the laptop screen. It looks like it takes about 15 seconds to cycle through those. Maybe your browser doesn't have enough memory to cache them so has to continuously reload them.

It doesn't look like it uses flash, just javascript and image files.

Fazor
2011-Nov-21, 07:04 PM
It displays 4 images on the laptop screen. It looks like it takes about 15 seconds to cycle through those. Maybe your browser doesn't have enough memory to cache them so has to continuously reload them.

It doesn't look like it uses flash, just javascript and image files.

Either that, or when the script 'ticks' it sends a small relay/ping/call/whatever back to the server. Might not really be transferring any data, just 'refreshing'. I know javascript is client-side so doesn't run off of the server, but the script I'm currently working on calls to an object embedded in the PHP via the CSS, which both reside server side and likely would create a small blip of data back-and-forth.

Jeff Root
2011-Nov-21, 07:23 PM
Well, that's most curious. I'm sure I would have noticed if the
images were cycling like that before. They are now. Can't be
a cache memory limit... Seems more like some kind of bug.
Except for the first image, the rotating images don't show up
on the page until they have displayed in the "View Image Info"
window. After seeing the first three images in that window,
those three are being displayed on the webpage. I'm sure
that if I click on the URL of the fourth image in the "View Image
Info" window, it, too, will display on the web jage....

Oh, really! Well, that isn't quite how it worked! There was only
one URL for the rotating image in the "View Image Info" window,
so there wasn't a second, third, and fourth to click on. Instead,
when I right-clicked the image on the web page, the currently-
displayed image showed up in the "View Image Info" window.
When I clicked during the time the fourth image was *intended*
to display, it displayed in that Info window I keep repeating the
name of. Then when I went back to the web page, it finally
displayed there, too.

I think I recall seeing a glitch just like that years ago. Different
browser, different operating system.

Although I still don't understand it, it turned out to be simpler
than I imagined it would be!

-- Jeff, in Minneapolis

HenrikOlsen
2011-Nov-21, 09:53 PM
I didn't look at the page as rendered, I looked at its source and assumed ads as that's the vast majority of stuff getting pulled in inventive ways. I'm ignoring the half of the total internet traffic that is porn in this assessment. :)

So, if they put a script in the webpage, the browser gets blamed
for "pulling" the ads, eh?
Well, I'm a programmer, not a minister. I look at what does the action, I don't assign blame.
If it's javascript, it's the browser that executes it and it's the browser that does the pulling.