So trying to not go into the technical details too much but when two instances federate with each other, they literally share all of the community, post and comment data with all other federated servers. But it’s the job of the host do manage that passing of data.
Now once the host decides to go offline, that activity of informing all other instances of “hey here’s something new about XYZ community!” no longer happens, but each instance still has the historical data from prior to them going offline. So you can still see that old data and still technically reply to it. Just that the host won’t tell other instances that you did reply.
Lets assume you have an account on Lemmy.world. Let’s also assume you see some post on Lemmy.ml. And finally lets assume you have a friend that’s actually on Mastodon. When you reply to that post on Lemmy.ml, Lemmy.world sends your reply to Lemmy.ml and then Lemmy.ml tells Mastodon (and all other federated instances) about your reply. But if Lemmy.ml decides to go offline, Lemmy.world has no where to send that reply to, so it’s only kept locally on Lemmy.world. The user on Mastodon can’t see it as their instance wasn’t told about it from Lemmy.ml as it went offline.
OK thanks. I am still a bit confused at how it works tho, if they did nuke the website, where would the data from the post and comments be stored
So trying to not go into the technical details too much but when two instances federate with each other, they literally share all of the community, post and comment data with all other federated servers. But it’s the job of the host do manage that passing of data.
Now once the host decides to go offline, that activity of informing all other instances of “hey here’s something new about XYZ community!” no longer happens, but each instance still has the historical data from prior to them going offline. So you can still see that old data and still technically reply to it. Just that the host won’t tell other instances that you did reply.
Replying to my own post with an example…
Lets assume you have an account on Lemmy.world. Let’s also assume you see some post on Lemmy.ml. And finally lets assume you have a friend that’s actually on Mastodon. When you reply to that post on Lemmy.ml, Lemmy.world sends your reply to Lemmy.ml and then Lemmy.ml tells Mastodon (and all other federated instances) about your reply. But if Lemmy.ml decides to go offline, Lemmy.world has no where to send that reply to, so it’s only kept locally on Lemmy.world. The user on Mastodon can’t see it as their instance wasn’t told about it from Lemmy.ml as it went offline.