[Standards] On PUB/SUB off-line event notification process

Justin Karneges justin-keyword-jabber.093179 at affinix.com
Thu Jan 13 18:08:24 UTC 2011

On Thursday 13 January 2011 09:21:05 Kaiduan Xie wrote:
> Hi, all,
> I am relatively new to XMPP world, and have a real problem to be
> addressed. The problem is, user subscribes to a particular event, when
> the event happens, system delivers an event notification to the
> interested users as soon as possible. This is a classical PUB/SUB
> system. One thing we need to consider is that the user may not stay
> connected all the time, for example he steps out of wireless coverage.
> We need to hold the event notification, and when the user becomes
> connected again, system delivers the event notification to the user.
> Base on my understanding, PUB/SUB does not define how to process
> off-line event notification, is there any extension covering this
> scenario? Any pointer is appreciated.

It is common for a user's server to save messages when a user is offline, so 
that when the user signs back on the server will send them.  So I would say if 
you want this effect, it is the responsibility of the user's server to provide 
this feature.  The pubsub service should not care about this.


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