1y ago

Communities should be able to move servers

Idea: if you mod a community on a lemmy.somewhere you should be able to migrate it to lemmy.elsewhere which would include all post & comment links being forwarded and subbed users having their subscription updated to reflect the new location.

I'm aware this would be a way down the road as user account migration alone is still not great but it would be a great feature for the fediverse to have to avoid centralisation and mod/server admin wars.

97 comments

Yes. It is a must have feature, actually.

I think it should be a "copy community" feature, then mods can just prevent posts in the old community and make a sticky that points to the new location.
Making users automatically subscribe to a community on a different instance (even if it's "the same community") is pushing it a bit in terms of moderator power. Also makes things worse in terms of exploits and others have pointed out.
- Mastodon uses aliasing for account migration. Your old account still exists on the original server, but it points to your new account. Following the old account automatically reroutes the follow to the new one. This could be done at the group level for lemmy without needing to manually lock the original group or ask users to find the new one.
  
  The issue is that users might object to subscribing to a community on a particular instance. I guess it's not the end of the world, you can always unsubscribe but I can imagine some people being very upset to be associated with certain politically leaning instances or worse.
- Have something like a mass message to subscribers with a link to the new instance.
  Then the old instance owner can take the old community name back.

Data portability for instances and users is imo an essential feature of any fediverse app, and sorely missing here on Lemmy/Kbin. We’ve already seen the issue surface with the hacks in instances last week and other instances going down suddenly. Like mastodon, we need to be able to take our data to whatever instance we want easily.

Risky. Some hacker exploits a vulnerability, takes over the community and migrates it to some other server.... then what?
Also, if a community leaves a specific server, what stops anyone else from re-creating it in the original server?
- To the first, rollback.
  To the second, is that a problem?
  
  To the first, rollback.
  for the first, you still have everyone subbed to the newly created community made by the attacker and all the links are still updated
  if instead of migrating everything right away, you have the original server of the community give redirects for each request, then that won't help if the original server is closing down, but it's probably the only right way to do it, I guess you could also have an angry instance admin disable the redirect to keep the community on their own server
  To the second, is that a problem?
  migrating and then recreating the original is actually an issue that Github has when you rename a repo, Github will give redirects for the links to the old name of the repo, but if you create another repo with the old name then the redirects are no longer served and if someone clicks on an old link then they end up at the repo that stole the name instead of the repo that was renamed
  so if let's say there was an official linus_tech_tips community on beehaw and they moved to lemmy.world, some random person could create the community again on beehaw after the migration to appear official and hijack all the old links out on the internet
  you fix that by keeping the old name reserved after migration, I don't really think that's a big problem in this case
  I actually liked @Neato@kbin.social's idea, instead of "migrating", you just copy the community and then send a message to every subscriber, close the original community, and put a pinned post at the top, maybe a message in the sidebar too
- 🥱
  
  Bro, this kind of comment is exactly why I left digg back in the day.

But that also makes it incredibly easy for communities on defederated servers to set up shop elsewhere.
And those communities may be the sole reason that the server was defederated in the first place.
I think a possible outcome is that the larger instances would have to put a stop to open creation of new communities, to prevent toxic groups from setting up shop and moving all their objectionable content and users into the space.
- I think it can be solved with a two step process. First, the mods of the community and only them can make a request to move from instance A to instance B, and second, the admins or mods of instance B approve the request, importing only the posts and comments from federated users.
- Let instance admins approve or deny the requests then
- A good community leaving a bad server can maybe work if the server doesn't just turn that off.
  A bad community that was hosted on a bad server can continue to be blocked on a server level.
  A good server tolerating a somewhat bad community will let users continue to block communities.
  Two good communities on one server might grow large and want to split servers.
- What if an instance were able to block specific communities on other instances without defederating?
  
  Users can already do so, what would instance-level block bring?
- Meh. I think if users focused more on blocking what they don't want to see instead of defederating, then this wouldn't be an issue.
  This is only a problem if you're one of the children who thinks: "I don't want to see something, so neither should anyone else."
  
  Yeah exactly, defederation should be limited to instances with incompetent or malicious admins, not with crap communities.

This is indeed a very important feature. It needs to take into account that if similar name community exists on another server how the merger would proceed as well in terms of exporting and importing cache of posts and comments.
But generally it should be easier to transfer from one instance to other.

At first I thought this was a great idea. But need to understand a bit more about the security implications for those that subscribe and post to the communities that want to do a move. It's one thing to trust your credentials to the host server, but quite another to implicitly trust the community mod who wishes to move. How would the old posts migrate? How would integrity of the constituent posts be preserved? How easy would it be to inject comments into to historical posts and republish them on the new, official, server? Could you be held liable (whether officially or through reputational risk) for posting content that wasn't really yours? Maybe there are good mechanisms to maintain integrity of data? I'm just not sure what they are.
I think there may be implications to this that are not obvious.
Happy to have these concerns assuaged, of course!
- Possibly some kind of democratic voting system would work? Or maybe the mods must all vote to do the move. Just an idea from when I saw another instance do a vote (for federation) using emojis, on a post, and they just counted them basically.
  (edit: The mastadon method seems feasible though posts need to move too.)

Just thought I'd flag this up: !issue_tracker@lemm.ee
It's a community to coordinate idea suggestions as well as image tracking. Perhaps this could be flagged up over there with a link back here or cross-posted.
- Does a bot post issues raised / commented on Lemmy, back into GitHub? Or is it just one directional?
  
  I think they are still figuring that out.

It's going to be incredibly necessary in the long run. Decentralized means some proportion of important communities are going to be on servers that will eventually be shut down for various reasons. Not everybody who's running an instance now will run it forever, but there may be communities with important conversations that folks will want to preserve.
Mastodon has account migration and Lemmy community migration should work similarly.
- Mastodon migration is still somewhat limited.
  Your posts don't transfer over, being the big catch.
  (Most everything else does, though)
  
  Ok, Calckey migration, then.
- And Lemmy should also have account migration.
  
  I made a tool that does this until we can get something baked into Lemmy itself: https://github.com/CMahaff/lasim
  There are a handful of other options out there too if ya search for em. Mine backs up / copies subscriptions, blocks, and a handful of profile settings.
  
  https://github.com/LemmyNet/lemmy/issues/1985

It should, but the Lemmy devs are swamped right now to add more features. Before, they had a pretty small dev team too. Now that there's a lot more eyes on Lemmy, hopefully we'll get more features while they iron out the stability issues.

Additionally, if your server disappears cough VLemmy cough you should be able to load a backup from somewhere and register your channels on another server. I realize this is still a crawl-walk-run scenario and that's going to be far in the future. But we can still hope for it.

server gets defederated, server moves to new server, defederation bypassed.
- This is part of why it's better to have users block servers instead of servers block servers.

And somehow be redundant/mirrored/backed up. Hacks, crashes, instance owner gets pissed, decides to take their sandbox and everything in it. Lots of ways and reasons that communities wlll disappear and a way to recover might be helpful.
- All of this could be there with the matrix.org protocol. The matrix protocol saves the comments and content in a directed graph, and that graph is copied to every instance, once one views it. It may not scale though. But it has benefits, such as encryption (making communities private or gated when under attack)
  
  I've been out of this loop for decades, but can see a train wreck if this vulnerability isn't addressed.
  Matrix says, "The functionality that Matrix provides includes: Creation and management of fully distributed chat rooms with no single points of control or failure..."
  I don't know what 'fully distributed' means. But one potential way of securing everything might be through something like torrenting. Have all Instances on several servers, such that the loss of a single server or Instance couldn't wipe out a community. If that happens more than a few times, I could see federating setback considerably.
  That's my two cents, and I'll leave it to the smarter and more capable folks to resolve.

Yep, I lost my communities when vlemmy shut down

Agreed!

Absolutely. I don’t think we really have fediverse until we get this.

I feel like this opens up the doors to "impostor" instances opening up, copying content from another instance and re-uploading it elsewhere. I can already think of tons of opportunities to commit various types of fraud this way, honestly.
There may also be legal issues with importing user account data and content, as well.
- Nothing is stopping anyone from copying content already.
  Legal issues - possibly, but then everything you write or do is federated already.
- Every instance is doing this, right now. When you post on one instance, every instance with a single subscriber to the community gets sent a copy.
  On kbin, even the media is stored on the instance. It helps distribute the load. Instances share posts between instances which can then each support many users.
  In terms of "taking over" a community. Not so easy.
  See, I could take fediverse@lemmy.world from my instance, do some SQL hacking and turn it into a local community. But, that would only work on my instance. Everyone else would still be following the original and the original would still exist.
  For it to work it needs to be a co-ordinated community move.
  Mods pick an instance with as much of the original data already federated as possible. They communicate the new home. People start subscribing, the old group is made read only with a message linking the new one.
  To keep existing posts though other instances would also need to SQL hack. So adding some features to communicate and automate the SQL effort would be a nice thing.
- 🥱

Yeah there HAS to be a way to cache all the posts comments replies etc at a certain point. Maybe every so often it flashes a cache on your server; saves everything; and lets you either create new with what you had OR move or.

What actually happens when servers are federated with one another? Does the content of each server get mirrored for redundancy, or does it just mean that users can see users, posts and communities from servers that are federated? When they defederate, does content that was previously visible to users just vanish completely, or is it merely that new content (created after defederation) will not be visible?
- Currently it just means you can post to communities on the servers yours is federated with.
  It doesn't mean you can sign into the other server with your account a la "sign in with Google/Twitter/etc." That needs to change first.

That would be a great feature.

That's just federation. I seeing this community on my instance. I am not a part of lemmy.world.
- no, being able to move the home server of a community is different from being able to join the community from other servers. It would mean that if a server has an issue or becomes an undesirable place, the community can live on by moving somewhere else.

I disagree. If one is that important, I say those mods need to create their own instance.
- They would still need to be able to migrate the community to their own instance.
  
  Yeah I understand that but I just disagree with automatically moving people around between instances.

97 comments