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AJAX instant Messenger
Posted: Wed Mar 04, 2009 11:48 am
by Omego2K
I am looking for a technique to implement an AJAX instant messenger. I understand that polling makes it possible, but if you look at say gmail and facebook instant messengers they seem to be, well, instant. I have tested it with two computers and I see no noticeable delay. I'm guessing that is considered a comet implementation, but I can't seem to see how it can be done. At least with php. I have tried it with ASP.NET and was able to do it with threading, however you can't thread with php. So am I missing something obvious? How is this being done? Especially since facebook uses php.
Re: AJAX instant Messenger
Posted: Wed Mar 04, 2009 4:11 pm
by VladSun
You could keep the HTTP connection opened and wait something to "happen" (by using sleep() in a loop). If nothing "happens" then close the connection just before the timeout.
Re: AJAX instant Messenger
Posted: Tue Mar 10, 2009 6:22 am
by Omego2K
wouldn't spinning like that be a huge a resource hog? sleep() pauses the thread itself I'm guessing?
Re: AJAX instant Messenger
Posted: Tue Mar 10, 2009 6:30 am
by VladSun
Omego2K wrote:wouldn't spinning like that be a huge a resource hog? sleep() pauses the thread itself I'm guessing?
While it's CPU friendly, it's not so Apache friendly (there is a limit of the maximum number of Apache spawned child processes)
So, if you are going to serve many and many clients don't use it, use AJAX instead.
But if you are going to use it for just a few clients (i.e. Intranet WWW application) it's better to use this approach.
Re: AJAX instant Messenger
Posted: Tue Mar 10, 2009 12:33 pm
by Omego2K
so what's the best server to use to accomplish this, on windows specifically? IIS?