Comments on: Simple Web Chat with Meteor Comet Server

By: cappadochian

cappadochian — Sat, 12 Sep 2009 11:48:54 +0000

hi!

i tried reverse proxy, restarted apache and i didn’t see the magic work…

Sat Sep 12 15:49:07 2009 debug New Meteor::Subscriber for 127.0.0.1
Sat Sep 12 15:49:07 2009 debug Meteor::Document: Request received for ‘/’
Sat Sep 12 15:49:07 2009 info document / 0 404
Sat Sep 12 15:49:07 2009 debug Will close Meteor::Subscriber for 127.0.0.1 when write buffer empty
Sat Sep 12 15:49:07 2009 debug Closed Meteor::Subscriber for 127.0.0.1

and where i had my starting page there’s only this:

Service Temporarily Unavailable
The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

——————————————————————————–

Apache/2.2.3 (CentOS) Server at 192.168.1.102 Port 80

any help would be appreciated.

thanks

By: Joe

Joe — Sat, 24 Jan 2009 05:33:36 +0000

Thanks for the response Andrew, Would you mind going into a little more detail as to how Meteor does this garbage collection or where I can find some more information about how it works? Thanks.

By: Andrew

Andrew — Mon, 19 Jan 2009 11:51:40 +0000

Jimmy – thanks for an excellent writeup. Regarding your ‘fourth way’ of co-locating Meteor and Apache on the same host with mod_proxy – yes, that does work, but it’s not recommended, because the very reason for using Meteor in the first place is that it’s optimised for handling lots of concurrent connections, whereas Apache is optimised for dealing with lots of *sequential* connections, closing them as quickly as possible (though it does also handle several at once, of course). So if you put Apache in front of Meteor, you lose much of the benefit of Meteor. At low volumes however, it will certainly work.

@Joe: The problem with IE7 is that it has an annoying habit of keeping connections open after the page has been destroyed – so you could have navigated away from the Comet-powered site, but there are still comet connections persisting in memory. You then rapidly encounter the two-connection limit. The solution to this is better garbage collection, which was implemented in Meteor thanks to a contributed solution several releases ago.

@Baderous: Meteor has no concept of authentication, but you could easily set up very obscure channel names, and there is no limit on the number of channels you can create, nor the number you can subscribe to at the same time.

By: BasTijs

BasTijs — Fri, 24 Oct 2008 10:11:06 +0000

Any idea on how to solve the IE refresh problem? Maybe with flush()?

By: Jimmy Vu

Jimmy Vu — Fri, 03 Oct 2008 05:16:49 +0000

@Baderous Meteor server does not support private channels (yet) but I think creating something random like UUID is OK.

By: Baderous

Baderous — Thu, 02 Oct 2008 17:49:55 +0000

Any idea how to implement private channels with this? Maybe creating random channel names that only the client and the server is aware of?

Nice article by the way. I came up with this exactly solution myself.

By: Joe

Joe — Mon, 29 Sep 2008 01:36:27 +0000

It seems the problem is being caused by IE’s strict connection limiting. Every website is only allowed two simultaneous to any web browser via an RFC standard. For some reason (IE sucks) IE isn’t closing these connections on page close, even if you manually call the ajax.abort() function they still aren’t closed. The one solution I have found is to have the client force the connection to reload. For example, if you put some code in the window.onload() function to post a message like “joe has entered the chat” solves this problem be forcing the connection to close and reopen. This isn’t a perfect solution but at least IE won’t hang anymore.

By: Joe

Joe — Thu, 25 Sep 2008 02:49:03 +0000

I have been looking into several different comet applications and so far, including this example, they work perfectly in IE7 until you refresh the page about 2-3 times. After then the page just infinitely loads and the chat doesn’t show up. If anyone has any ideas as to why this is happening in IE I’d love to hear it.