this post was submitted on 21 May 2024
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That's a nice idea but has some pretty obvious technical drawbacks that aren't discussed in the blog article:
The complexity of most networks grows about exponentially with the number of connections between the entities. It gets immensely more computationally expensive that way and you're bound to use lots of additional network traffic and total cpu power that way.
And some (a lot of) people like using social media on their phones instead of a computer. You're bound to drain their batteries real fast by moving application logic there.
Other than that I like the general idea. The Fediverse should be more dynamic. Caching and discovery have some big issues in the current form. That should be tackled and we need technical solutions for that. And the current architecture isn't perfect at all.
Furthermore, if talking about the edge where networks are smarter... Why then move it into the browser which isn't at the edge? Wouldn't that be an argument to invent edge-routers like in edge computing? I mean with c2s you have a server on the one side and a client on the other side with the edge somewhere in between. If you now flip it you end up in a different situation. But there's still nothing at the edge where you could introduce some smarts...
Messaging applications (that need to be online all the time) don't have this issue. Mobile email clients are even more conservative in resource usage. Why would an AP client be any different?
You are not going to be transcoding video or executing complex machine learning analysis on the device. I can reasonably argue that a local-first AcvitityPub application would be no different in resource usage than something like a modern XMPP or Matrix client.
Because with all of that, messaging, email, xmpp, matrix and ActivityPub most of the magic happens on the server. Take email for example. The server takes care to be online 24/7. It provides like 5GB of storage for your inbox that you can access from everywhere. It filters messages and does database stuff so you can habe full text search. Same with messaging. Your server coordinates with like 200 other servers so messages from users from anywhere get forwarded to you. It keeps everything in sync. Caches images so they're available immediately.
That allows for the clients/Apps to be very simplistic. It just needs to maintain one connection to your server and ask if there's anything new every now and then. Or query new data/content. Everything else is already taken care for by the server.
OP's suggestion is to change that. Move logic into the client/App. But it's not super easy. If you now need to be concerned on the client with maintaining the 200 connections at all times instead of just 1 to see if anyone replied... Your phone might drain 200 times as much battery. And requiring the phone to be reachable also comes with a severe penalty. Phones have elaborate mechanisms to save power and sleep most of the time. Any additional network activity requires the processor and the modem to stay active for longer periods of time. And apart from the screen thats one of the major things that draws power.
What I am proposing is not getting rid of the server, just reducing the amount of functionality that depends on it. You won't be connecting with 200 different servers, you will still have only one single node responsible to get notifications.
Regarding storage: I can speak from experience that it you can have a local-first architecture for structured data that does not blow up the client. In a previous work, we built a messenger app where all client data was stored on PouchDB which could be synced via a "master" CouchDB. All client views would be built from the local data. Of course, media storage would go to the cloud, which means that the data itself was only highly-compressible text. You can go a looooong way with just a 1GB of storage, which is well within the limits of web storage
Hmmh. But how would that then change Mastodon not displaying previous (uncached) posts? Or queries running through the server with it's perspective?
And I fail to grasp how hashtags and the Lemmy voting system is related to a client/server architecture... You could just implement a custom voting metric on the server. Sure you can also implement that five times in all the different apps. But you'd end up with the same functionality regardless of where you do the maths.
And if people are subscribed to like 50 different communities or watch the 'All' feed, there is a constant flow of ActivityPub messages all day long. Either you keep the phone running all day to handle that. Or you do away with any notification functionality. And replicating the database to the device either forces you to drain the battery all day, or you just sync when the user opens the App. But opening Lemmy and it takes a minute to sync the database before new posts appear, also isn't a great user experience.
I'd say we need nomadic identity, more customizability with the options like hashtags, filters and voting. Dynamic caching because as of now Fediverse servers regularly get overwhelmed if a high profile person with lots if followers posts an image. But most of that needs to be handled by servers. Or we do a full-on P2P approach like with Nostr or other decentralized services. Or edge-computing.
I don't quite get where in between federated and decentralized (as in p2p) your approach would be. And if it'd inherit the drawbacks of both worlds or combine the individual advantages.
And ActivityPub isn't exactly an efficient protocol and neither are the server implementations. I think we could do way better with a more optimized, still federated protocol. Same with Matrix. That also provides me with a similar functinality my old XMPP server had, just with >10x the resource usage. And both are federated.
You default to push (messages that come through the server), and you fall back to pull (the client accessing a remote server) when you (your client) is interested in fetching data that you never seen.
hashtags, sorting and ranking methods, moderation policies, and pretty much everything aside from the events themselves are just ways to visualize/filter/aggregate the data according to the user's preferences. But it turns out that this is only "complex" when your data set is too large (which is bound to happen when your server has to serve lots of users). If you filter the data set at the client, its size becomes manageable.
Nostr is not p2p, and p2p is not what I am talking about. Having logic at the client does not mean "p2p".
Yes, because the XMPP server is only concerned with passing messages around!
Ah, you're right. Nostr uses relays. Now I know what the name stands for. Sounds a bit like your proposal in extreme. The "servers" get downgraded to relatively simple relays that just forward stuff. The magic happens completely(?) on the clients.
I'm still not sure about the application logic. Sure I also like the logic close to me (the user.) The current trend has been towards the opposite for quite some time. Sometimes the explanation is simple: If you do most things on the server, you retain control over what's happening. That's great for selling ads and controlling the platforms in general. On the other hand it also has some benefits for power efficiency on the devices. I'm not talking about computing stuff, but rather about something like Google Cloud Messaging which has the purpose of reducing the amount of open connections and power draw and combine everything into a single connection for push messages. In order to do decide when to wake a device, it has access to to the result of the filtering and message priorization. Which then needs to be done server-side.
I'm also not sure with the filtering of hashtags. I mean if you subscribe to a hashtag. Or want to count the sum to calculate a trend... Something needs to work through all the messages and filter/count them. Doesn't that mean you'd need all Mastodon's messages of the day on your device? I'm sure that's technically possible. Phones are fast little computers. And 4G/5G sometimes has good speed. But l'm not sure what kind of additional traffic you'd estimate. 50 Megabytes a day is 1.5GB for your monthly cellular data plan. A bit less because sometimes people are at home and use wifi... But then they also don't just use one platform, but have Matrix, Lemmy and Mastodon installed. And you can't just skip messages, you'd need to handle them all to calculate the correct number of upvotes and hashtag use. Even if the user doesn't open the app for a week.
I don't quite "feel it". But I also wouldn't rule out the possibility of something like a hybrid approach. Or some clever trickery to get around that for some of the things a social network is concerned with...
Or like something I'd attribute more to edge computing. The client makes all the decisions and tells the edge (router) exactly what algorithm to use to do the ranking, how to do the filtering and when it wants to be woken up... That device does the heavy lifting and caches stuff and forwards them in chunks as instructed by the client.
You wouldn't need that. Think in terms of XMPP: a server could create the equivalent of a MUC room for tags, and the client could "follow" a tag by joining the room. The server would then push all messages it receives to that room. This scales quite well and still puts the client in control of the logic.
Similar architecture could be used for groups.
A Matrix app connects to a Matrix server, same for XMPP and email. Sometimes they might connect to a few more for extra accounts.
An AP client in the way you're describing will need to connect to thousands of servers (at least). The whole point of federation is that you get content from a large network but through a single source.
So does a web browser. So does a mobile Lemmy client like Jerboa. "Connecting to thousands of servers" doesn't mean anything, if these connections are sporadic and uncorrelated.
How will you get a list of users on different servers without connecting to them?
Changing this will require the client to search through a bunch of servers itself, or use a 3rd party search engine.
How will you get trending hashtags from servers without connecting to them?
How would you fetch posts, their score and comments from servers without connecting to them?
In the same way that a RSS reader knows which feeds to download?
Yes, but the 3rd party search engine can be specialized. It could be a service that indexes all of the fediverse, or it could be a "standard" search query with some special operators.
Your application will already receive updates from the communities you are subscribed to. In the case where you want to browse by /all, then yes, on first load your client will be making a bunch of queries to different servers that have communities to get a list of updates. But this would be an issue only on first load, because subsequent queries would be "give me all events that happened since the last time I visited".
But if you really don't want to run this on your device, then how about this: someone develops a "client" which is actually an aggregator of all the different instances which can then be used as web service that provides an API for end-users. This way, we still get to enjoy a distributed system, we still have a client-first application and we also get the benefit of having a service that makes it easier for the people who think that "federation is too complicated for non-techies."
I meant how will you fetch a list of users from which you could generate recommendations.
I guess with proper integration for different search engines (or maybe just something like Searx) this could be useful.
Currently a Lemmy app loads all posts from a single server (which in turn, aggregates posts from different servers), and then loads stuff like images from their respective hosts. With your suggestion, every post might come from a different server, any of which might be temporarily down (not uncommon unfortunately). Caching will make this issue and the other issues less severe, but it won't solve them.
I don't disagree with the idea BTW, I just honestly think it's not practical (at least with ActivityPub).
Why? Take our interaction, for example. the community is on lemmy.world, you are on lemm.ee and I'm on communick.news. My response generates an activity that is sent to LW, and LW then announces that activity to all the servers who have at least one subscriber. If LW went down, you wouldn't be able to see this message until it came back up and it started processing the federation queue again. Right?
The same thing would happen in a "message-relay" system. My client would send a message to LW, and LW would then send the activity to lemm.ee, which would then "push" it to you. If any of the servers went offline, the whole process would stop at the node that is offline and would then resume when it came back up.
If you load /all, you will get posts from communities on a bunch of different servers. If you load your subscriptions, those communities still likely come from multiple servers.
Currently, lemmy.world, lemm.ee, and communick.news are running all the time, with random downtime due to issues/maintenance. When I log in to lemm.ee, I fetch the posts from lemm.ee, including any posts that may have been posted to lemmy.world and communick.news while I was logged out, even if both are down while I'm logged in.
I guess my main issue with your idea is that it will (IMO) encourage people to host more servers, which in turn could lead to communities being more spread out across servers, which will then make the experience worse since a client side implementation depends much more heavily on servers being available.
Why? If anything, I believe that it would be the opposite. Less "responsibility" on the servers would mean better capacity to scale and serve more clients on the same hardware and (if the identity is not dependent on the server and can be easily portable) it would mean less attached value to the server itself, so people wouldn't care so much about "what instance they are joining".
The best analog there is to what I am proposing is movim, and if you go take a look at their server list, you will see quite a limited amount of servers even though it has as many active users as Lemmy.
I really agree with your premise. Less responsibility on the server means less depending on it. We'd gain independence, could move accounts and do some more nuanced things. But I really think the less your own server or relay does, the more you're prone to suffer from network outages, other servers becoming unavailable etc. So you'd need to duplicate everything no matter what to compensate for that. And you introduce lots of additional traffic by fetching all the hashtags from everywhere. Or you'd end up in the same situation as before where they're subject of availability on your instance or perspective on the network.
Plus you want unsubscribed old posts showing up and a perspective that's independant of the chosen instance. So you basically need to replicate everything everywhere. And this introduces additional complexity and resource usage and your goal was to reduce that. (And federation becomes just an inconvenience and additional unnecessary work at that point.)
It's not that it's technically difficult. We could do that. And you're right by pointing at XMPP and Movim and stuff. But that also doesn't solve most of the issues you outlined in your initial post. It's even more narrow in how you rely on your own server and shaping your perspective on the whole network.
And sometimes this is what we want. People do dedicated instances to a topic. For example a Mastodon server for IT and tech people. Of course you want IT related stuff to show up on your main page. And we sometimes want moderation and a place to have civilized discussions. Not a place of anarchy and shitposting like on 4chan. That requires some form of hierarchy or democracy. And at the end of the day the server operators are responsible for what content is shared (publicly) via their infrastructure...
So I'd say you can't achieve all your goals with ActivityPub. You need to think bigger. Maybe do away with federation altogether. Since federation is all about having different instances with a different focus and perspective on the same network. Maybe focused on a language or subject or sub-community of users, different rules and moderation. And you want more a unified perspective, everyone gets the same and less intermediaries. I'd say that is fundamentally incompatible with this form of federation and kind of out of scope. You probably want a network without that hierarchy. And that comes with different technical challenges and advantages.
(And suppose we extended ActivityPub. Instead of separating and moving stuff to the client, we could imagine you install a Lemmy or Mastodon server/instance on your computer or phone. Along your browser. You'd have it all on your device and could configure it like you wanted. I'm not sure if that'd be a superior solution.)
I feel like one of the issues with these "new plan for X" essays or posts is that readers usually interpret it as something to completely replace the status quo. It's not the case. I'm not saying that everyone should start using this. I'm not saying that everyone should leave Mastodon. I'm not saying that all server-focused software using AP needs to go away.
I'm just saying that the current approach is not the only one and that Mozilla could have benefited from trying something different. I'm saying that Federation might be the right unit of organization for some cases, but that there is a whole world of possibilities where Federation is not so suitable.
I get it, it makes no sense to say that a network with 1M+ active users is "doing everything wrong" and that we need to start anew. I am not arguing the case to change those that are already here. I am arguing for changes that could help those that looked at "Federated Social Media" and went away because this model didn't work for them.
Hmm, I get you. But I don't think that's what this discussion is about. I'm more concerned with the technical difficulties / impossibilities / inconsistencies with the approach. Less so if it should replace the current solution or a possible upgrade path. That's something to worry about later. It's more like I don't think it's going to work properly. It's more combining the disadvantages of two different approaches.
But I'm happy if someone goes ahead and does a better approach. I also see the shortcomings of the current solution. Maybe I'm being too pessimistic.
To me, this makes it sound much more attractive to run a server, as it will be easier to do. Though I guess this is subjective.