#lemmy/#kbin has a problem that #mastodon hasn’t even attempted to solve; groups and what happens when they get popular.
#Communities, #groups, #magazines, whatever they are called are implemented as #Actors in #ActivityPub. They are basically just *very* popular users who boost a *lot*.
You can’t just distribute them across instances the way normal actors do. Whichever server hosts @technology@lemmy.ml or @technology@beehaw.org is going to get HOSED on the regular.
@schizanon @technology@lemmy.ml @technology@beehaw.org Yep. I expect that long-term a lot of instances will limit the ability to create groups (as Beehaw does) or place restrictions on the size a group is allowed to grow before asking that group to move to another/their own instance or ask for finances to help with the costs.
While it’s true that the hosts of popular communities will get more traffic, it’s actually not as bad as it first seems.
Every Lemmy instance with at least one subscriber in that popular community will act as a mirror. That means that users who are just reading posts and comments will not cause any additional load on the home-instance of the popular community, because they are consuming local copies of the posts and comments.
This will actually help scaling a lot, and is in fact exactly how many centralized platforms scale (by creating a bunch of read-only copies of content).
As long as we can distribute the Lemmy userbase between different instances (and avoid creating one or two centralized super-instances), we can take a lot of advantage of this mirroring and the scaling will be quite good!
In those cases, the action will need to propagate back to the home server (that’s where the “hosts of popular communities will get more traffic” comes from), but keep in mind - people usually read at least one or two orders of magnitude more than they write.
Did you post this from Mastodon? I wish I could tell where this came from.
Basically if I understand this right, if you have an instance with a very popular community on it. It is likely that it will need some massive infrastructure scaling if it wants to handle the enormous amount of world wide traffic?
@Nymphioxetine posted from mastodon (because Lemmy is slow right now😊)
Yes. If you run the server, then you are the source of truth of that community. All other servers that federate your community query your server to access the community and show it to their users.
So if you run a server and a community explodes there, you might only have 500 users on your instance, but you might have 50k users reading that community and interacting with it from other Lemmy instances, thus your server needs to scale to 50k users worth.
And ever more essential, your server is the source of truth of that community. So if your server is hacked or corrupted or deleted, that community is gone. Other instances don’t mirror it (except for temporary caching), so the Lemmy network essentially is a trust network of other people maintaining servers long term (and each inventing a monetary system to pay for it). I still think the network might be better than a centralized system like reddit, but it definitely has a lot of growing and policies that need to be sorted out very soon
So are these other servers just routing requests from their users to your server’s community? Or are they actually copying everything over every so often (caching) and serving up the requests themselves? How real time is it, I guess is what I’m asking?
Yeah, apparently I was wrong about this (still learning lemmy and fediverse stuff…). Text content of posts and comments are “synced” to your server and stored in your database there. Then future requests for that content are served from your instance. So its not as bad as I thought it was (the network load should be lower since you aren’t acting as entirely a proxy, more like a cache), but database bloat will be a huge problem (its already a big problem in other federated things like mastodon and matrix, where every server ends up saving everything they want into their own database).
I’m not sure what happens when the original server goes down, does the federated servers discard that data? Or do we each maintain a forever copy until we want to get rid of it ourselves? There’s also some notes I’ve seen about how servers only incrementally cache federated content (only posts and comments that are viewed by someone are fetched, and new comments may not be fetched until someone wants to see it)… so not everybody has a “pure and full” copy of posts necessarily.
But overall I wonder how all the various sysadmins hosting these lemmy instances will deal with the expotential growth they’re going to see, or if smaller instances will start defederating to save on hardware costs (no reason for my tiny instance that only talks about blue shiny rocks to federate with lemmy.world and store all that content)
So there is no way to horizontally scale?
The network can actually scale quite well thanks to the fact that other instances will act as mirrors of communities!
No. The “single source of truth” is the instance hosting the community. If it goes down the community itself goes down with the ship. The only way to prevent it is to have a IT infrastructure that can provide redundancy
If it’s just a temporary outage, whatever the mirror has received prior to the outage will be shown to users on that other instance but only local interactions for that instance will update it, when it comes back up, things like votes and comments will be synchronized again across all of the instances.
For permanent outages, the community will just need to be started again on a new instance.
it may be worth putting a bug request on the activitypub github, because I agree that could become a huge problem, but its also alot of work to implement because most instances will need to update to the newest activitypub standard once they approve a new version of the standard.
