Thinking more about this, I want... subscriber to ack to service the pubsub event message service to retry to subscriber by a configurable method if no ack service to report fail to publisher when retries spent for a specific subscriber service to report done to publisher when all subscribers either acked or failed
Thoughts? On Wed, Feb 3, 2010 at 8:07 PM, Liam <[email protected]> wrote: > > Understood. I'm going to chat about this with Jack Moffitt at the XMPP > > Summit next week to see if he has any insights. I'm not a web guru. :) > > Tell him I said hi (I've been working on the strophe pubsub plugin a lot > recently :) > > I improved my browser-tab-close issue by ensuring that strophe issues a > disconnect on tab-close. However there is no way to know that a stanza which > tcp transfers ok has been processed by the client without an explicit ack > mechanism. Closing a tab, etc. won't close the socket right away, or even > stop reading it. > > The nature of "publish-subscribe" implies greater reliability than IM, to > my mind. One can implement a custom ack for peer-to-peer messaging easily > enough via <message/>, but publishers shouldn't get acks from zillions of > subscribers. > > Liam > > > > On Tue, Feb 2, 2010 at 12:25 PM, Liam <[email protected]> wrote: > >> >The core problem here is that presence is not necessarily reliable or >> >immediate. Does the notification ever show up anywhere >> >> No, it never shows up. I suspect the browser gets it but my handler for >> XmlHttpRequest is gone by then, so the data is tossed. >> >> >> >> On Thu, Jan 28, 2010 at 3:52 PM, Liam <[email protected]> wrote: >> >>> Any comments on the issue of reliable delivery to offline subscribers? >>> >>> I seem to have this issue with ejabberd. Having configured >>> pubsub#notification_type = normal (which queues items to offline >>> subscribers), if I disconnect a subscriber (by closing a browser tab running >>> strophe) and immediately publish an item, it doesn't always show up on >>> reconnect, presumably because it is "delivered" before ejabberd knows the >>> user is offline. If I wait a bit before publishing, the item does show up. >>> >>> >>> >>> On Thu, Jan 28, 2010 at 2:17 AM, Liam <[email protected]> wrote: >>> >>>> Perhaps I'm missing something here... >>>> >>>> That presence-based delivery is an optional service feature implies that >>>> items published are normally queued to node subscribers when they are >>>> offline, and later delivered when they sign on. However I can't find this >>>> explicitly stated in the spec. >>>> >>>> Also, the impact of persist_items on delivery to offline subscribers is >>>> not discussed. Is a non-persisting node inherently presence-based delivery? >>>> (Intuitively, I'd say not.) >>>> >>>> That on_sub_and_presence is an option for send_last_published_item could >>>> imply that items published when a subscriber is offline need not be queued >>>> for later delivery, which seems very strange. >>>> >>>> Also, I see no method for reliable delivery of items to offline >>>> subscribers... IQ notifications seem to address this only for online >>>> subscribers. This seems like a significant omission. >>>> >>>> I discovered this when I configured a node on ejabberd as follows, >>>> expecting it to queue items if the subscriber is offline, as for normal >>>> messages (which it doesn't): >>>> >>>> <field var='pubsub#notify_retract'><value>0</value></field> >>>> <field var='pubsub#persist_items'><value>0</value></field> >>>> <field var='pubsub#publish_model'><value>open</value></field> >>>> <field var='pubsub#access_model'><value>whitelist</value></field> >>>> <field >>>> var='pubsub#send_last_published_item'><value>never</value></field> >>>> >>>> Thanks, >>>> >>>> Liam >>>> >>>> >>> >> >
