[jdev] MU-Conference and network connection loss

Heiner Wolf wolf at bluehands.de
Wed Jun 16 13:54:42 CDT 2004


I get an "interesing" behaviour with MU-Conference when the client's internet network connection drops and comes back. One source of connection loss is when a WLAN goes down temporarily. My client re-joins chat rooms silently. 

BUT: after the client sends the new presence-available to the room, it gets a presence-UNavailable from the room, even before it gets the presence-available back. It seems as if the room notices very late that the user disconnected and tells everyone. It does it so late, that the client already tried to join again. From the clients point of view its like: instead of the presence-available acknowledgement, it gets a presence-unavailable, which is very confusing. I need an ugly hack, that "ignores" presence-unavailable as long as the presence-available is not acknowledged. Sounds bad and may behave bad under different conditions.

This works quite deterministic, so that I guess wildly, that the conf component is not notified of the connection loss at all. Only when the client comes back, the server seems to notice and tell the conf component about the client's connection loss. But then its too late. 

In other words:

Client->Server: Connection setup, login, etc.
Client->Conf  : presence-available
Conf->Client  : presence-available (ack)
        -- network loss --
        -- network back --
Client->Server: New connection setup, login, etc.
Client->Conf  : presence-available
Conf->Client  : presence-UNavailable        <--- this one should not be here
Conf->Client  : presence-available (ack)

  Server: jabberd 1.4.3
  Conf: MU-Conference 0.6.1-20031116

Any comments from the MU-conf/server development?

Dr. Klaus H. Wolf
bluehands GmbH & Co.mmunication KG
+49 (0721) 16108 75
LLuna: Jabber enabled virtual presence on the web / http://www.lluna.de/
Galactic developments: Open source future history / http://www.galactic-developments.com/

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