Does anyone know of a good document describing how mastodon federation works? How do new instances become discovered, what determines whether other instances federate with them or not by default? Also (especially), what is the role of relays? I keep encountering references to relays, and lists of them, but I haven't found anything describing their function, their role in the network distinct from server instances. Any breadcrumbs would be greatly appreciated!
@interfluidity
I have been trying to understand this issue of 'discovery'. What I know understand is that when an instance is created. It basically has no knowledge of anything other instance. And it gains knowledge when a user on your instances 'follows' or 'boosts' a user/toot from another instance. I have heard of mailing list like bots that you can join and send any message to all users. Is that what you mean by relays?
@kevix I find lists like this https://github.com/brodi1/activitypub-relays
So far, the best explanation I have is from @aredridel moments ago, that they merge and copy federated timelines to give instances a more comprehensive picture of what's going on than lazily acquiring toots from local follows would do.