ejabberd - Comments for "Flexible Offline Message Retrieval - not stopping flood of offline messages"

So the key here is to send a

adiohaion — Sun, 16 Jul 2017 13:47:12 +0000

So the key here is to send a presence with a negative priority after logging in and before the headers are fetched.
If I add this step, it acts as expected, and I don't get the flood of messages.
Thanks!

> So if Flexible Offline

badlop — Fri, 14 Jul 2017 10:31:00 +0000

> So if Flexible Offline Message Retrieval is enabled before the initial presence, I think it shouldn't send the offline messages after the initial presence is sent.

Right, and that behavior works correctly for me using ejabberd 17.07, as described in the second flow shown in https://xmpp.org/extensions/xep-0013.html#flow

See this example:
1. user1 sends a message to his contact user33, which is offline
2. user33 logins with negative priority. Consequently, user33 does not receive the offline message
3. user33 sends IQ as XEP-13 says, and receives a response indicating he has offline messages pending:

<iq type='get' id='asd'>
  <query xmlns='http://jabber.org/protocol/disco#items'
         node='http://jabber.org/protocol/offline'/>
</iq>
<iq xml:lang='es'
        to='user33@localhost/tka1'
        from='user33@localhost'
        type='result'
        id='asd'>
  <query node='http://jabber.org/protocol/offline'
        xmlns='http://jabber.org/protocol/disco#items'>
    <item node='1499979486413720'
        name='user1@localhost/tka1'
        jid='user33@localhost'/>
  </query>
</iq>

4. Now user33 sets a positive presence priority. He receives a response, but not the offline message flood. So, it works correctly:

<presence xml:lang='es'>
  <show>away</show>
  <priority>1</priority>
  <status>Busy</status>
  <c hash='sha-1'
        node='http://tkabber.jabber.ru/'
        ver='r8V40m6ZPI/XkmBng8oguZ139bA='
        xmlns='http://jabber.org/protocol/caps'/>
</presence>
<presence xml:lang='es'
        to='user33@localhost/tka1'
        from='user33@localhost/tka1'>
  <c hash='sha-1'
        node='http://tkabber.jabber.ru/'
        ver='r8V40m6ZPI/XkmBng8oguZ139bA='
        xmlns='http://jabber.org/protocol/caps'/>
  <x xmlns='vcard-temp:x:update'/>
  <priority>1</priority>
  <show>away</show>
  <status>Busy</status>
</presence>

I've also tried not using XEP-0013: if client doesn't send IQ in step 3, then in step 4 he receives the offline message flood.

Thanks for the quick

adiohaion — Wed, 12 Jul 2017 11:37:31 +0000

Thanks for the quick response!

If you look at the Process Flow in the doc you mentioned (https://xmpp.org/extensions/xep-0160.html#flow), you can see in #5:

"When the recipient next sends non-negative available presence to the server, the server delivers the message to the resource that has sent that presence. (Alternatively, the server may support Flexible Offline Message Retrieval (XEP-0013), although that functionality is not described herein.)"

This tells me that the alternative of Flexible Offline Message Retrieval is ignored in this document, when it says:
"Now the recipient authenticates with the server and sends initial presence (with a non-negative priority) to the server. [...] The recipient's server now delivers the offline message to that resource"

Also, in XEP-0013 it states:
"The protocol enables a connecting client to retrieve its offline messages on login in a controlled fashion, without receiving a flood of messages"

And

"Upon receiving a service discovery request addressed to a node of "http://jabber.org/protocol/offline" (either a disco#info request [...] or a disco#items request [...]), the server MUST NOT send a flood of offline messages if the user subsequently sends initial presence to the server during this session."

So if Flexible Offline Message Retrieval is enabled before the initial presence, I think it shouldn't send the offline messages after the initial presence is sent.
It's not a critical issue, but it's a lot of traffic to the client that could be avoided.

Do I understand this wrong?

Thanks again.

When you send initial

badlop — Wed, 12 Jul 2017 09:57:34 +0000

When you send initial presence in step 5, if it has positive priority, mod_offline sends all the messages, as specified in https://xmpp.org/extensions/xep-0160.html See:

> Now the recipient authenticates with the server and sends initial presence (with a non-negative priority) to the server. [...] The recipient's server now delivers the offline message to that resource