Yeah there are issues. I don't think the Lemmy devs anticipated this kind of expansion in such a short period. Some of the issues should be resolved in the next version. Especially the removal of websockets is something we're looking forward to
Part of me wonders if we're starting to see a limitation of ActivityPub? I might be wrong but I don't see any sort of batching in the protocol? So every post, comment or heck every upvote will not only trigger a service call from your machine to your instance but would it not also trigger dozens or more service calls from your instance out to all of the federated servers? And as more and more instances come online the number of service calls per action starts to grow exponentially?
I donโt think itโs a protocol issue. Itโs not that different from how e-mail lists work. Except most users are on a very small number of big instances (which makes it easier).
In Usenet itโs even worse as messages have to go through multiple hops and arenโt filtered by what groups users subscribe too, and that worked decades ago on hardware less powerful than a cheap cloud instance is today.
Lemmy is still tiny in comparison so I think it must be a software issue.
Ya I keep forgetting it's similar to email. But at the same time for every reply, is it not similar to doing a reply-all, with each federated instance being in the recipients list? And don't forget what happens when everyone starts doing a reply-all when on an email with a large distribution list... The email server ends up taking hours or even days to processes that queue. Hopefully I'm over thinking it, but I'll learn more over the next few weeks as I study ActivityPub more and more.
Itโs not that different from how e-mail lists work.
Lemmy hasn't even reached 1990's level email system design for a database-backend MTA. The outbound delivery queue has no management tools, is not saved when a sever stops, and runs in-process with the same service as the rest of lemmy_server - for interactive end-users. Federation really needs to be moved to a separate server service, the massive number of connections to send votes and comments isn't even holding up under current loads. And this is without major social events with dozens of comments per second, people leaving Reddit was largely limited by signup problems - major servers crashing and restricted signup approvals.
Huh! That's possible, but that doesn't sound right to me. I think for example that if I post a comment on a lemmy.ml thread, my client sends a request to A, lemmy.world, and then A sends a request to B, lemmy.ml, and then third-parties C would see the result of my like if they individually request content from B.
I don't think cross-instance interaction is shared with every federated instance at once. They each need to go "find out" on their own.
From what I can tell, and I've only been reading the docs for a few days now. Everything is considered an actor.... Users, comments, posts, communities and even the instance itself. When you create a new post to a community you're essentially replying to that community's actor. If that community is not on your instance then your instance needs to post that reply via an ActivityPub service call. Now once the target instance receives that post request it adds it to it's database but then that instance needs to inform all of the other instances that something has been added to that community. So it'll queue up a service call to every other instances that has federated with that community's instance.
So in the end if you're a user on instance A but trying to create a post to a community that belongs to instance B, A has to tell B about the post. Next B then, since it's the owner of that community, has to inform instance C,D,E, etc... that there's now a new reply to that community.
Again I might still be missing something as I've only been reading these for about a day or so. But if this is correct then each action anyone takes produces a lot of network traffic to update every other instance in the fediverse.
Part of me wonders if weโre starting to see a limitation of ActivityPub? I might be wrong but I donโt see any sort of batching in the protocol?
Agreed. There is also a lot of protocol boilerplate overhead, digital signing, to send a single Like of a comment one to one server. Thee implementation also has no way for the server operator to know that another server is backing up or failing, and when the server is stopped - the queue gets lost.
at least I know this silly thing is working. I was debating on creating my own instance b/c nothing seemed to be working, but now I can put away the dockerfiles :)
I just tested inbound federation from sh.itjust.works and it was instantaneous.
For the past few days, none of my outbound from lemmy.world to anywhere, including sh.itjust.works has succeeded and it took hours for the few that made it through before that.
So I'm guessing its a .world issue of some kind.
Probably the sheer amount of activity, not helped by the Federation model of every synced server connecting to every other synced server.
Since there are a lot of users on lemmy.world, we're probably connecting to a lot of different servers, to say nothing of going in the other direction, where we're also getting hammered by a lot of other servers that are accessing posts hosted here.
This topic is related to different stuff from that. Accounts are exclusive to their instance, and it's the instance (e.g. lemmy.world) that talks to other ones (e.g. lemmy.ml).
Your lemmy.world account is only for lemmy.world and can't sign in to any other Lemmy instance, but it doesn't need to, because you can access all other Lemmy instances that Lemmy.world is linked to and hasn't blocked. So you can go to [email protected] from here by either searching that in the topbar, or you should be able to via this link: [email protected]