IE pools XMLHttp connections. To quote the new "ASP.Net Ajax in Action" book verbatim:
Another interesting tidbit is that in IE, only two connections
can be opened at a time...
Question: Now, How do I verify this?
Answer: How about opening a multiple connections to a long running query?
This was precisely what I had done. I had IE open XmlHttp requests to a
Here are the results:
The operation had the thread wait for 10 seconds at the server. Now look at how the results are clumped by two. So IE QUEUEs all your async XmlHttp requests (I assume it allows as many as you want to open... The test opened 10 as shown above), and services them by a pool of 2 XmlHttp objects.
Script# and Nikhil, you guys rock :)