[Standards-JIG] MUC traffic issues
gnauck at ag-software.de
Sun Feb 19 16:40:26 UTC 2006
i had a small discussion with Ulrich about it in the JSF meeting today,
and we had discussions about that in the jdev room quite often in the
With very busy chat servers and chat rooms all current MUC
implementaions scale very bad, because too much bandwidth is wasted and
too many message and presence stanzas are routed.
5 users in a room room at conference.jabber.org, user1 sends a message to
the room. All users are connected to jabber.org in the scenario
user1 -> jabber.org -> conference.jabber.org
the messages reached conference.jabber.org which creates now 5 new
messages, because the message must be delivered to all participants.
conference.jabber.org |-> jabber.org -> user1
|-> jabber.org -> user2
|-> jabber.org -> user3
|-> jabber.org -> user4
|-> jabber.org -> user5
we send 2*usercount messages. If the Muc server is build in the server
or cluster we could reduce the messagecount by 50% with a good software
design. But if MUC is used of the component protocol we can't.
So Ulrich proposed to use a combination of muc and pubsub to reduce the
traffic which is a great idea.
The message flow would be the following then:
conference.jabber.org -> MUC_Pubsub |-> user1
We send only usercount+1 messages now.
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