Scalability. This is much better for people running a lemmy instance without terabytes of disk space.
this post was submitted on 09 Jan 2024
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subscriptions are per-community
You shine a torch at someone in the dark, you can see more than just them though
Yeah but that's a waste of light. Why use a floodlight when you can use a laser?
in america, we drive on a parkway and park on a driveway
You still have maps and GPS though.
So im guess you’re asking why things behave this way?
There are two parts.
- Synchronising all of the data from all of the communities would consume more data and network resources. So instead, it’s only done if a user subscribes. Should help save on some data and synchronisation.
- You may also want to know that a community exists on another instance even though you’ve never subscribed to it. And that’s fair IMO. Being able to explore what’s on another instance directly from yours makes sense. But that’s what the other instance is for. Go to their web page and explore from there. This is a decentralised system. Sure there are some rough edges … like being able to subscribe directly from the other instance should help smooth over the UX (and I think this might have been added in v0.19?)
Thanks for the useful insight.
No worries!!
The ActivityPub protocol works by sending out every action on one server to any subscribed server. The subscribed servers save this data and make it available to the local users. If it worked the way you described, every server on the fediverse would store all the data from the whole fediverse. That seems wasteful.
Because that would multiply the amount of work lemmy.world (and the other site involved) has to do by some number, which would make the whole site slower for arguably little benefit.