Recovering federation automatically
A bug in a client package caused the federation to become out of sync for some users (applications/hubl#1055 (closed))
They were members of a distant circle, but their user object was not aware of this connection (the backlink had not been created successfully), and so it didn't show up on their user
Fixing the bug and then resending the backlinks manually put the federation back into sync. Other times the federation could become out of sync e.g. if the receiving server goes down and the connection times out
In all cases that the backlink is unsuccessful, the sender will save an Activity
object to the database with failure information and the payload of the activity. If the activity is old, then it might be out-of-date, so something like resending all of these activities periodically isn't a viable solution in itself
A script which could repair a federation, triggered manually, would be very useful, or at least a way to see in which ways the federation is out of sync, so that we don't need the users to tell us that their circles aren't showing up
Ping @jbpasquier we were discussing this last week