S2S Dialback issue
Occasionally Tigase XMPP Server is unable to establish S2S communication with other XMPP servers due to issue with dialback - it returns error:
Remote server not found. A remote server or service specified as part or all of the JID of the intended recipient does not exist. S2S - destination host not found
Remote server usually reports it as connection timeout or that it is not able to find dialback key, what forces remote server to fail during dialback.
#5 Updated by Andrzej Wójcik over 4 years ago
- Status changed from In Progress to In QA
- Assignee changed from Andrzej Wójcik to Artur Hefczyc
It looks like this issue was caused by a few things:
Tigase.IM was running version of Tigase XMPP Server in which it was possible to overload S2S connection establishing thread, which would lead to sending dialback request after another dialback request was sent with new secret.
Tigase XMPP Server established more than 1 connection to remove server (as remote server was a cluster - tigase.im) and each node received different secret for authentication which could lead some connections to fail as Tigase XMPP Server was keeping only last generated secret as valid.
Currently some things changed:
Tigase XMPP Server is using multiple threads for DNS resolution, so such overload is not possible now.
Since S2S now implements XEP-0185 (see #980) each generated secret sent to remote server will be validated (not only last one)