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Most use cases of ActivityPub would be better off as Atom or RSS feeds

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Re: Most use cases of ActivityPub would be better off as Atom or RSS feeds

#2

Post by edhelas »

I agree with those statements.

That is why we are using Atom on top of Pubsub in XMPP to built social networking features. The sub-layer is changing (Atom is embeded into Pubsub XML on top of TCP real time streams, XMPP) but in the end the content is not "transformed" but just "transported".

Atom already provides most of what ActivityPub provides regarding the description of the content (rich content, attachments, external links, comments, reply-to...).

You just need to put it on top of a layer that specifies how this content can be accessed, subscribed and delivered. In our case it's XMPP Pubsub but it can also be pure HTTP requests. Good thing is that moving from one to another is pretty easy.

This is a static page generated from Atom articles published on a XMPP Pubsub feed from TechCrunch RSS/Atom feeds https://nl.movim.eu/?node/news.movim.eu/TechCrunch, we can even generate back an Atom feed from it easily. On a similar way you can handle personal "blogs" https://nl.movim.eu/?blog/edhelas@movim.eu with likes, shares and comments :)

The XMPP Standard Fundation is working for more than 10 years now on integrating those concepts together and glueing existing standards to deliver social-features next to IM features and so on...

You don't have to create "new standards that will cover everything else" (see https://xkcd.com/927/) if you can just glue the existing ones together.

Re: Most use cases of ActivityPub would be better off as Atom or RSS feeds

#3

Post by cjslep »

I feel need to address some points of the authors (I realize it's a hot take so it's meant to be biased):

> But what does this buy us? For the most part it means that every piece of content everyone writes needs to be replicated to every point in the federation mesh to be useful.

This is because ActivityPub is tied to RDF and linked data concepts. This isn't specific to ActivityPub, just a criticism of the linked data web. As we will see later, the author doesn't quite understand that linked data can be fetched only on demand and represented otherwise as only an IRI, reducing data replication to a minimum. It depends on the specific ActivityPub implementation.

> This isn’t creating a distributed network, this is creating a whole bunch of massive points of failure.

This is a pretty ungenerous characterization. It's a distributed system where robustness is not a part of the protocol. It needs to be solved elsewhere, so innovation is needed.

> Meanwhile, what does this buy you? Immediacy of updates? Okay, does it really matter how quickly you see someone’s new content, if it’s worth seeing?

I think this is another ungenerous characterization. It buys a federated set of communities and applications that can exchange linked data in real time.

> For example, user-agents and RSS providers can use the If-Modified-Since: header to only get the feed updates if the content has changed since the last fetch.

ActivityPub also has a diffing system of data in place with Update activities too.

> Oh, and ActivityPub stuff generally also means that all attachments and other content also get replicated.

This is not true and is entirely implementation specific. If Mastodon creates local caches of federated data, that's it's design choice. Other applications can always fetch-on-demand and go back to the Pull Model.

That being said, static sites are not served by ActivityPub so that portion of criticism is definitely spot on.

Re: Most use cases of ActivityPub would be better off as Atom or RSS feeds

#4

Post by giancarlostoro »

That's weird that you have to download from a whole other instance, I would have thought the client requests what it needs when it needs it, and points to some sort of UUID to another instance that can be queried later by a client.

I'm really lovestruck by the capabilities of ActivityPub and I want to work on a federated Tumblr alternative, but I just have not found the time with all the personal stuff I have going on currently, but ideally you wouldn't store everything on your instance (unless you rather cache it, now THAT makes perfect sense to me) you would let a browser request certain things via AJAX and maybe your instance could tell the other instance, hey guy you keep asking me for this waaay too often, can you cache it for me? kthxbai and those who don't do it would be considered broken instances and possibly rejected? Not sure I feel like the protocol is still way too young. Also not sure about the security implications but let's assume that sane SSL cryptomagic is a requirement for blogging instances (or just all of them).

Re: Most use cases of ActivityPub would be better off as Atom or RSS feeds

#5

Post by phoe-krk »

The author doesn't see the difference between ActivityPub as a specification and implementations of ActivityPub that make some implementation choices of their own. No one forces the AP clients or implementations to build local caches, no one forces them to replicate everything on their own.

Re: Most use cases of ActivityPub would be better off as Atom or RSS feeds

#6

Post by aepiepaey »

giancarlostoro wrote: post #4

That's weird that you have to download from a whole other instance, I would have thought the client requests what it needs when it needs it, and points to some sort of UUID to another instance that can be queried later by a client. I'm really lovestruck by the capabilities of ActivityPub and I want to work on a federated Tumblr alternative, but I just have not found the time with all the personal stuff I have going o…

Pet peeve: it's "would have", not "would of".

A problem with opportunistic caching would be degraded user experience for the first user that sees some specific piece of content, since they'd have to wait (potentially for seconds) for their instance to fetch the content from the origin instance.

Re: Most use cases of ActivityPub would be better off as Atom or RSS feeds

#8

Post by xj9 »

aepiepaey wrote: post #6
giancarlostoro wrote: post #4

That's weird that you have to download from a whole other instance, I would have thought the client requests what it needs when it needs it, and points to some sort of UUID to another instance that can be queried later by a client. I'm really lovestruck by the capabilities of ActivityPub and I want to work on a federated Tumblr alternative, but I just have not found the time with all the personal stuff I have going o…

Pet peeve: it's "would have", not "would of". A problem with opportunistic caching would be degraded user experience for the first user that sees some specific piece of content, since they'd have to wait (potentially for seconds) for their instance to fetch the content from the origin instance.

pleroma's media proxy is works just like that and the user experience is fine. actually, i've run instances that don't have caching configured and it still works fine (if a bit unfriendly to other instances).

Re: Most use cases of ActivityPub would be better off as Atom or RSS feeds

#10

Post by viswanathdurbha »

I like the W3C WebSub standard (formerly known as PubSubHubbub) which uses RSS/Atom underneath to syndicate content. The only catch is that it requires a publicly visible URL for callback. This is great for services like Feedly but may not work for individual subscribers who just want to use a client application and not run a server with public facing URL. But maybe, this is better than running a Mastodon server because we can still have the benefits of a simple Atom format and protocol.
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