Client presence update creates flood of presence updates from gateway

[dazzzl]

First, it is related to #218 and #204, but it is a general problem. Therefore, I created a new issue.

Setup:
Prosody trunk (~May 2017) with latest Spectrum in gateway mode.

Problem:
On resource changes the status (e.g., available -> away or away -> available). Prosody spread this update to all buddies in the roster. Spectrum receives for each buddy in this gateway a presence update. The answer of Spectrum is an update of the presence of the gateway for all resources, even if the gateway status was not changed. The result is: If one resource is changing the presence status, all resources gets a flood of duplicated presence updates for the gateway.

Expected result:
Only on presence update per resource and only if the gateway status is changed.

Solution:
I made a quick hack in User::handlePresence Line 302:

if (presence->getTo().toString().find("@") != std::string::npos) return;

[languitar]

Is there no chance to fix this in Spectrum? I think I am experiencing the same thing with ejabberd, but I have to check this again before I can say something real.

[dos1]

I can confirm that presence flooding happens with ejabberd as well.

[thundergreen]

Don't know if this isbreoated to this topic but I get annoying leave messages for my discord transport .I think its spectrum related

[dos1]

With ~600 contacts and 2+ resources usually connected this issue gets really hard to stand, so as a hacky personal workaround I'm using ACLs to prevent presence updates from reaching Spectrum contacts (they still reach the transport itself). In its effects it should be analogous to the workaround as presented by @dazzzl, but it doesn't need patching and recompiling :)

[languitar]

@dos1 could you explain how the ACLs work. Maybe I can use that as a workaround then, too.

[dos1]

I denied both "Presence-Out" and "Presence-In" because reasons, but generally you just need to block Presence-Out.

[edhelas]

I'm also experiencing the same issue, would it be possible to fix it ? It creates a lot of useless traffic on the server.

[thundergreen]

Any idea how to fix that with ejabberd ACL? Or how is it supposed to work?