multiplexing question (does it work as expected?)

[Vasya Novikov]

Hi Lift community! I wonder: is the current behavior of multiplexing
expected?:

* open a first tab with: http://demo.liftweb.net/
* open the same page on a second tab

Check out network console. What I see is 3-5 requests per second with
empty contents.

What is happening? Is this really the expected behavior?
I first found it out on my own site, thinking this is a
misconfiguration.. But it happens on the official Lift demo, too.

// I'm sorry if that's a popular question, please point me in the right
direction if I should just read some previous mailing list topic.


--
Vasya Novikov

[Antonio Salazar Cardozo]

Multiplexing has a few different components, but I'm guessing you're asking

about multiplexing over the same connection to the server. Two tabs/windows

cannot currently easily share connections in browsers. As such, if there are

two tabs open, they must have independent connections to the server—even

though these connections may ultimately communicate with a single CometActor

instance.

Additionally, if multiple CometActors are referenced on one page, they

communicate through one connection to the server.

Now, to your observed behavior. Browsers have a limit on the number of

connections they may have to the same host. That limit varies by browser.

Lift keeps track of connections per session; in cases where a session is

trying to maintain more comet connections than the browser would support

having simultaneously, Lift serializes the long-poll connections into short-

poll connections. This means a lot of requests with no response data, but

it ensures that if, say, you open another tab, you will still be able to load it

normally.

That said, this shouldn't kick in at just two tabs unless you're using a browser

we don't recognize properly. I believe we default to serializing early, but if

we recognize the browser as one that supports many connections, we pay

attention to that number of connections.

Thanks,

Antonio