Does CNN Money use pull or push to get the market updates?

You can see the market change in every 2 seconds on money.cnn.com. It looks like the client pulls the data from the server. Is this correct?

What did you find when you looked at the source code?

I cannot tell. Can you?

I haven't looked. My bet is a pull as push technology is pretty resource-expensive.

I did a simple experiment:

While CNN Money showing the changing market data, I disconnected the network connection from my computer.
The last data remains on the page (values, timestamp, ...) without any changes during the period of disconnection.
The disconnection time is about a hour. Then I connected the computer to the internet, and saw the updates resumed in about 5 minutes after the connection.

I do not think CNN Money server keeps the connection information (or client session) after the connection are gone for over a hour. So server pushing in this
situation is impossible.

The code is in the numbered JavaScript file. It is an interval polling the server, it is basic Ajax, looks to have an iframe fallback if I am reading the code correctly. I just glanced at it.

Basic idea is make a call to the server after a set period of time looking for new data. If he call errors out, probably disconnected and change the polling time to a larger time difference. When you get new data, you just update the page.

Eric

[I knew Eric wouldn't be able to resist poking at the code.

]