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  3. I have deeply mixed feelings about #ActivityPub's adoption of JSON-LD, as someone who's spent way too long dealing with it while building #Fedify.

I have deeply mixed feelings about #ActivityPub's adoption of JSON-LD, as someone who's spent way too long dealing with it while building #Fedify.

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  • evan@cosocial.caE evan@cosocial.ca

    @cwebber @kopper @hongminhee

    I would be strongly opposed to any effort to remove JSON-LD from AS2. We use it for a lot of extensions. Every AP server uses the Security vocabulary for public keys.

    cwebber@social.coopC This user is from outside of this forum
    cwebber@social.coopC This user is from outside of this forum
    cwebber@social.coop
    wrote last edited by
    #107

    @evan @kopper @hongminhee The problem is that signing json-ld is extremely hard, because effectively you have to turn to the RDF graph normalization algorithm, which has extremely expensive compute times. The lack of signatures means that when I boost peoples' posts, it takes down their instance, since effectively *every* distributed post on the network doesn't actually get accepted as-is, users dial-back to check its contents.

    Which, at that point, we might as well not distribute the contents at all when we post to inboxes! We could just publish with the object of the activity being the object's id uri

    kopper@not-brain.d.on-t.workK evan@cosocial.caE smallcircles@social.coopS rigo@mamot.frR 4 Replies Last reply
    0
    • cwebber@social.coopC cwebber@social.coop

      @evan @kopper @hongminhee The problem is that signing json-ld is extremely hard, because effectively you have to turn to the RDF graph normalization algorithm, which has extremely expensive compute times. The lack of signatures means that when I boost peoples' posts, it takes down their instance, since effectively *every* distributed post on the network doesn't actually get accepted as-is, users dial-back to check its contents.

      Which, at that point, we might as well not distribute the contents at all when we post to inboxes! We could just publish with the object of the activity being the object's id uri

      kopper@not-brain.d.on-t.workK This user is from outside of this forum
      kopper@not-brain.d.on-t.workK This user is from outside of this forum
      kopper@not-brain.d.on-t.work
      wrote last edited by
      #108
      @cwebber @hongminhee @evan admittedly, codeberg.org/fediverse/fep/src/branch/main/fep/8b32/fep-8b32.md does kind of solve this specific problem. the json canonicalization used there is much lighter than rdf canonicalization (which iceshrimp had to implement in dotNetRdf specifically for its ld signature support, so tooling availability is not really an excuse in favor of json-ld either!)
      cwebber@social.coopC 1 Reply Last reply
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      • kopper@not-brain.d.on-t.workK kopper@not-brain.d.on-t.work
        @cwebber @hongminhee @evan admittedly, codeberg.org/fediverse/fep/src/branch/main/fep/8b32/fep-8b32.md does kind of solve this specific problem. the json canonicalization used there is much lighter than rdf canonicalization (which iceshrimp had to implement in dotNetRdf specifically for its ld signature support, so tooling availability is not really an excuse in favor of json-ld either!)
        cwebber@social.coopC This user is from outside of this forum
        cwebber@social.coopC This user is from outside of this forum
        cwebber@social.coop
        wrote last edited by
        #109

        @kopper @hongminhee @evan Interesting... I guess it means you can't re-compact with a new outer context, but maybe that's fine

        1 Reply Last reply
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        • cwebber@social.coopC cwebber@social.coop

          @evan @kopper @hongminhee The problem is that signing json-ld is extremely hard, because effectively you have to turn to the RDF graph normalization algorithm, which has extremely expensive compute times. The lack of signatures means that when I boost peoples' posts, it takes down their instance, since effectively *every* distributed post on the network doesn't actually get accepted as-is, users dial-back to check its contents.

          Which, at that point, we might as well not distribute the contents at all when we post to inboxes! We could just publish with the object of the activity being the object's id uri

          evan@cosocial.caE This user is from outside of this forum
          evan@cosocial.caE This user is from outside of this forum
          evan@cosocial.ca
          wrote last edited by
          #110

          @cwebber @kopper @hongminhee I talk about this in my book. Unless the receiving user is online at the time the server receives the Announce, it's ridiculous to fetch the content immediately. Receiving servers should pause a random number of minutes and then fetch the content. It avoids the thundering herd problem.

          patmikemid@sfba.socialP julia@eepy.moeJ cwebber@social.coopC 3 Replies Last reply
          0
          • evan@cosocial.caE evan@cosocial.ca

            @cwebber @kopper @hongminhee I talk about this in my book. Unless the receiving user is online at the time the server receives the Announce, it's ridiculous to fetch the content immediately. Receiving servers should pause a random number of minutes and then fetch the content. It avoids the thundering herd problem.

            patmikemid@sfba.socialP This user is from outside of this forum
            patmikemid@sfba.socialP This user is from outside of this forum
            patmikemid@sfba.social
            wrote last edited by
            #111

            @evan @cwebber @kopper @hongminhee I think that is a better algorithm than a brain dead exponential back off. Perhaps put the two together.

            evan@cosocial.caE 1 Reply Last reply
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            • kopper@not-brain.d.on-t.workK kopper@not-brain.d.on-t.work
              @evan @gugurumbe it's infeasible to preload all contexts, pretty much every pleroma instance hosts their own context on their own instance for example. then there is the obvious interop problems of how to handle contexts for new extensions your software is not aware of (though pretending like they're empty might work i guess?)
              gugurumbe@mastouille.frG This user is from outside of this forum
              gugurumbe@mastouille.frG This user is from outside of this forum
              gugurumbe@mastouille.fr
              wrote last edited by
              #112

              @kopper It does not; if a malicious context redefines the security properties then the JSON-LD processor will understand the data differently than the unaware processor.

              1 Reply Last reply
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              • patmikemid@sfba.socialP patmikemid@sfba.social

                @evan @cwebber @kopper @hongminhee I think that is a better algorithm than a brain dead exponential back off. Perhaps put the two together.

                evan@cosocial.caE This user is from outside of this forum
                evan@cosocial.caE This user is from outside of this forum
                evan@cosocial.ca
                wrote last edited by
                #113

                @patmikemid I call it trust, then verify. Usually caching the data with a ttl of a short number of minutes is enough.

                @cwebber @kopper @hongminhee

                cwebber@social.coopC 1 Reply Last reply
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                • kopper@not-brain.d.on-t.workK kopper@not-brain.d.on-t.work
                  @evan @gugurumbe it's infeasible to preload all contexts, pretty much every pleroma instance hosts their own context on their own instance for example. then there is the obvious interop problems of how to handle contexts for new extensions your software is not aware of (though pretending like they're empty might work i guess?)
                  evan@cosocial.caE This user is from outside of this forum
                  evan@cosocial.caE This user is from outside of this forum
                  evan@cosocial.ca
                  wrote last edited by
                  #114

                  @kopper @gugurumbe

                  https://en.wikipedia.org/wiki/Cache_%28computing%29

                  kopper@not-brain.d.on-t.workK natty@astolfo.socialN mia@void.rehabM 3 Replies Last reply
                  0
                  • evan@cosocial.caE evan@cosocial.ca

                    @kopper @gugurumbe

                    https://en.wikipedia.org/wiki/Cache_%28computing%29

                    kopper@not-brain.d.on-t.workK This user is from outside of this forum
                    kopper@not-brain.d.on-t.workK This user is from outside of this forum
                    kopper@not-brain.d.on-t.work
                    wrote last edited by
                    #115
                    @evan @gugurumbe i know what caching is, thanks. in fact, my current project is building one that's tailor made for solving the activitypub thundering herd problem (codeberg.org/KittyShopper/middleap)

                    i've been trying to keep civil through this thread largely because i started the conversation mentioning software i (temporarily) help maintain and therefore represent it even implicitly, but leaving that aside and letting my own personal thoughts enter the picture:

                    i think this passive aggressive reply is the last straw. thinking that i somehow know enough to write code for this protocol without knowing what a cache is? plugging your book in a network largely developed by poor minorities (i myself have the rough equivalent of less than 40 USD in my bank account total)? this inability to consider change? ("as2 requires compaction",
                    because you're the one defining the spec saying it does), the inability to consider the people and software producing and building upon the data, as opposed to the data itself? the inability to consider the consequences of your specifications and how they're being used in the real world?

                    i honestly do not know if this line of thought is truly capable of leading this protocol out the slump it's currently in. if you're insistent on shooting yourself in the foot, so be it, but please take the time to consider how this behavior affects other people.

                    i've largely been burnt out of interacting in socialhub and other official protocol communities due to exactly this behavior, whether from you or others with influence on the final specs, and the only reason i keep trying is because of what's probably a self-destructive autistic hyperfixation on this niche network and trying to make it actually work for me and my friends, as opposed to
                    receiving funding from the well-known genocide enablers at meta and trying to shove failing standards where they don't belong.

                    please be a better example. if the protocol was actually desirable then sure, you may have earnt it, after all, atproto is teeming with silicon valley e/acc death cult weirdos and yet people seem to prefer it. have you wondered why?
                    or do you prefer to dismiss anything not coming from you without thinking about it
                    esm@wetdry.worldE evan@cosocial.caE 2 Replies Last reply
                    0
                    • evan@cosocial.caE evan@cosocial.ca

                      @cwebber @kopper @hongminhee I talk about this in my book. Unless the receiving user is online at the time the server receives the Announce, it's ridiculous to fetch the content immediately. Receiving servers should pause a random number of minutes and then fetch the content. It avoids the thundering herd problem.

                      julia@eepy.moeJ This user is from outside of this forum
                      julia@eepy.moeJ This user is from outside of this forum
                      julia@eepy.moe
                      wrote last edited by
                      #116

                      @evan@cosocial.ca @cwebber@social.coop @kopper@not-brain.d.on-t.work @hongminhee@hollo.social shared inboxes are a thing, Evan

                      The protocol isn't
                      just how it was initially defined. Protocols evolve and change from their ideals to fit the needs of their operation, and getting rid of individual inboxes is one of those changes.

                      Social media platforms are real-time- you can't just defer stuff like that.

                      evan@cosocial.caE 1 Reply Last reply
                      0
                      • julia@eepy.moeJ julia@eepy.moe

                        @evan@cosocial.ca @cwebber@social.coop @kopper@not-brain.d.on-t.work @hongminhee@hollo.social shared inboxes are a thing, Evan

                        The protocol isn't
                        just how it was initially defined. Protocols evolve and change from their ideals to fit the needs of their operation, and getting rid of individual inboxes is one of those changes.

                        Social media platforms are real-time- you can't just defer stuff like that.

                        evan@cosocial.caE This user is from outside of this forum
                        evan@cosocial.caE This user is from outside of this forum
                        evan@cosocial.ca
                        wrote last edited by
                        #117

                        @julia @cwebber @hongminhee @kopper

                        Hi! 👋🏼 Nice to meet you. I'm well aware of `sharedInbox` and helped design it.

                        Realtime is an illusion. You can make it pretty convincing.

                        Your users are mostly not online. Remote users are mostly not online. Tracking the last time remote and local users were seen can help you prioritize local and remote delivery.

                        It's a lot better to deliver to the tiny percent of users currently online first rather than delivering to the user named `aaaaaaaaamng` first.

                        julia@eepy.moeJ panos@ibe.socialP 2 Replies Last reply
                        0
                        • evan@cosocial.caE evan@cosocial.ca

                          @julia @cwebber @hongminhee @kopper

                          Hi! 👋🏼 Nice to meet you. I'm well aware of `sharedInbox` and helped design it.

                          Realtime is an illusion. You can make it pretty convincing.

                          Your users are mostly not online. Remote users are mostly not online. Tracking the last time remote and local users were seen can help you prioritize local and remote delivery.

                          It's a lot better to deliver to the tiny percent of users currently online first rather than delivering to the user named `aaaaaaaaamng` first.

                          julia@eepy.moeJ This user is from outside of this forum
                          julia@eepy.moeJ This user is from outside of this forum
                          julia@eepy.moe
                          wrote last edited by
                          #118

                          @evan@cosocial.ca @cwebber@social.coop @hongminhee@hollo.social @kopper@not-brain.d.on-t.work I feel like deferring activity resolution and publishing based on online status would only serve to create more reasons for your average person to feel that the fediverse is unstable- explaining the logistics of the herd problem to someone who doesn't know what a distributed system is is kinda difficult.

                          evan@cosocial.caE 1 Reply Last reply
                          0
                          • evan@cosocial.caE evan@cosocial.ca

                            @kopper @gugurumbe

                            https://en.wikipedia.org/wiki/Cache_%28computing%29

                            natty@astolfo.socialN This user is from outside of this forum
                            natty@astolfo.socialN This user is from outside of this forum
                            natty@astolfo.social
                            wrote last edited by
                            #119

                            @evan@cosocial.ca @kopper@not-brain.d.on-t.work @gugurumbe@mastouille.fr Evan, to put it bluntly, the status quo only creates a further divide between the "big certified implementations" and the small implementation independent developers can make without worrying about making the implementation vulnerable-by-default

                            There could totally be a body that at least
                            attempts to standardize well-known LD prefixes while retaining compatibility with JSON-LD (like IANA and protocol schemes), but there isn't

                            There could be a
                            subset of JSON-LD that prohibits common pitfalls, but there is not one. In fact, there are very few high-quality openly available libraries that can process ActivityPub objects. There is no way to declare the actual shapes of objects without heavy fuzzing.

                            There is no safe amount of JSON-LD in a distributed network where context URIs may fade in and out of existence. I'm saying distributed because that's essentially what happens in practice over sufficient time.

                            Can we for the love of all that's serializable shrink the state space of this mess? It's possible and it's actionable, without anyone left out. We don't need a Rube-Goldberg machine to share a JPEG online

                            1 Reply Last reply
                            0
                            • kopper@not-brain.d.on-t.workK kopper@not-brain.d.on-t.work
                              @evan @gugurumbe i know what caching is, thanks. in fact, my current project is building one that's tailor made for solving the activitypub thundering herd problem (codeberg.org/KittyShopper/middleap)

                              i've been trying to keep civil through this thread largely because i started the conversation mentioning software i (temporarily) help maintain and therefore represent it even implicitly, but leaving that aside and letting my own personal thoughts enter the picture:

                              i think this passive aggressive reply is the last straw. thinking that i somehow know enough to write code for this protocol without knowing what a cache is? plugging your book in a network largely developed by poor minorities (i myself have the rough equivalent of less than 40 USD in my bank account total)? this inability to consider change? ("as2 requires compaction",
                              because you're the one defining the spec saying it does), the inability to consider the people and software producing and building upon the data, as opposed to the data itself? the inability to consider the consequences of your specifications and how they're being used in the real world?

                              i honestly do not know if this line of thought is truly capable of leading this protocol out the slump it's currently in. if you're insistent on shooting yourself in the foot, so be it, but please take the time to consider how this behavior affects other people.

                              i've largely been burnt out of interacting in socialhub and other official protocol communities due to exactly this behavior, whether from you or others with influence on the final specs, and the only reason i keep trying is because of what's probably a self-destructive autistic hyperfixation on this niche network and trying to make it actually work for me and my friends, as opposed to
                              receiving funding from the well-known genocide enablers at meta and trying to shove failing standards where they don't belong.

                              please be a better example. if the protocol was actually desirable then sure, you may have earnt it, after all, atproto is teeming with silicon valley e/acc death cult weirdos and yet people seem to prefer it. have you wondered why?
                              or do you prefer to dismiss anything not coming from you without thinking about it
                              esm@wetdry.worldE This user is from outside of this forum
                              esm@wetdry.worldE This user is from outside of this forum
                              esm@wetdry.world
                              wrote last edited by
                              #120

                              @kopper @evan @gugurumbe thank you for saying this; the relatively poor DX is one thing, but i could get around that if it weren't for the insistence by the authors and major developers here on minimizing much of the very real problems of this protocol/network and then complaining about those who look elsewhere without considering why they would want to do that

                              i continue to maintain existing stuff for this network, but i'm incredibly hesitant to make anything new mostly due to the reasons stated above - especially when we have other options now

                              1 Reply Last reply
                              0
                              • evan@cosocial.caE evan@cosocial.ca

                                @kopper @gugurumbe

                                https://en.wikipedia.org/wiki/Cache_%28computing%29

                                mia@void.rehabM This user is from outside of this forum
                                mia@void.rehabM This user is from outside of this forum
                                mia@void.rehab
                                wrote last edited by
                                #121

                                @evan @kopper @gugurumbe what, you got a book on caching you want to plug too?

                                1 Reply Last reply
                                0
                                • kopper@not-brain.d.on-t.workK kopper@not-brain.d.on-t.work
                                  @evan @gugurumbe i know what caching is, thanks. in fact, my current project is building one that's tailor made for solving the activitypub thundering herd problem (codeberg.org/KittyShopper/middleap)

                                  i've been trying to keep civil through this thread largely because i started the conversation mentioning software i (temporarily) help maintain and therefore represent it even implicitly, but leaving that aside and letting my own personal thoughts enter the picture:

                                  i think this passive aggressive reply is the last straw. thinking that i somehow know enough to write code for this protocol without knowing what a cache is? plugging your book in a network largely developed by poor minorities (i myself have the rough equivalent of less than 40 USD in my bank account total)? this inability to consider change? ("as2 requires compaction",
                                  because you're the one defining the spec saying it does), the inability to consider the people and software producing and building upon the data, as opposed to the data itself? the inability to consider the consequences of your specifications and how they're being used in the real world?

                                  i honestly do not know if this line of thought is truly capable of leading this protocol out the slump it's currently in. if you're insistent on shooting yourself in the foot, so be it, but please take the time to consider how this behavior affects other people.

                                  i've largely been burnt out of interacting in socialhub and other official protocol communities due to exactly this behavior, whether from you or others with influence on the final specs, and the only reason i keep trying is because of what's probably a self-destructive autistic hyperfixation on this niche network and trying to make it actually work for me and my friends, as opposed to
                                  receiving funding from the well-known genocide enablers at meta and trying to shove failing standards where they don't belong.

                                  please be a better example. if the protocol was actually desirable then sure, you may have earnt it, after all, atproto is teeming with silicon valley e/acc death cult weirdos and yet people seem to prefer it. have you wondered why?
                                  or do you prefer to dismiss anything not coming from you without thinking about it
                                  evan@cosocial.caE This user is from outside of this forum
                                  evan@cosocial.caE This user is from outside of this forum
                                  evan@cosocial.ca
                                  wrote last edited by
                                  #122

                                  @kopper @gugurumbe sorry, friend, for the curt response. I'm flying today for a death in the family, and I'm having a hard time keeping a lot of conversations going. You should have heard me trying to chair a meeting as I went through airport security!

                                  evan@cosocial.caE 1 Reply Last reply
                                  0
                                  • evan@cosocial.caE evan@cosocial.ca

                                    @kopper @gugurumbe sorry, friend, for the curt response. I'm flying today for a death in the family, and I'm having a hard time keeping a lot of conversations going. You should have heard me trying to chair a meeting as I went through airport security!

                                    evan@cosocial.caE This user is from outside of this forum
                                    evan@cosocial.caE This user is from outside of this forum
                                    evan@cosocial.ca
                                    wrote last edited by
                                    #123

                                    @kopper @gugurumbe

                                    Anyway, to me, a backwards-incompatible change is absolutely the worst possible choice we could make for the Fediverse. It splits the network, possibly permanently. We have about 100 implementations of ActivityPub, and they can't all upgrade at the same time.

                                    evan@cosocial.caE kopper@not-brain.d.on-t.workK smallcircles@social.coopS 3 Replies Last reply
                                    0
                                    • evan@cosocial.caE evan@cosocial.ca

                                      @kopper @gugurumbe

                                      Anyway, to me, a backwards-incompatible change is absolutely the worst possible choice we could make for the Fediverse. It splits the network, possibly permanently. We have about 100 implementations of ActivityPub, and they can't all upgrade at the same time.

                                      evan@cosocial.caE This user is from outside of this forum
                                      evan@cosocial.caE This user is from outside of this forum
                                      evan@cosocial.ca
                                      wrote last edited by
                                      #124

                                      @kopper @gugurumbe I just don't think the downside of having to cache the results of context URL fetches outweighs that.

                                      1 Reply Last reply
                                      0
                                      • evan@cosocial.caE evan@cosocial.ca

                                        @kopper @gugurumbe

                                        Anyway, to me, a backwards-incompatible change is absolutely the worst possible choice we could make for the Fediverse. It splits the network, possibly permanently. We have about 100 implementations of ActivityPub, and they can't all upgrade at the same time.

                                        kopper@not-brain.d.on-t.workK This user is from outside of this forum
                                        kopper@not-brain.d.on-t.workK This user is from outside of this forum
                                        kopper@not-brain.d.on-t.work
                                        wrote last edited by
                                        #125
                                        @evan @gugurumbe

                                        here is a backwards incompatible change in a fep you authored:
                                        codeberg.org/fediverse/fep/src/branch/main/fep/b2b8/fep-b2b8.md#attributedto (specifically, the Link-and-name bit. mobile Firefox does not let me send highlights apparently)

                                        the http signature draft->rfc change is backwards incompatible.

                                        mastodon api to c2s is backwards incompatible for client developers (and,
                                        if done correctly, would require long and unwieldy migrations on servers. ask firefish.social users how those kinds of migrations end up)

                                        whatever the replacement for as:summary as content warnings would be backwards incompatible. replacing as:name with as:description for media alt text is backwards incompatible (gotosocial did it, and we adapted)

                                        making webfinger optional is backwards incompatible

                                        backwards compatibility is not here yet. now is the second best time to get rid of legacy cruft
                                        esm@wetdry.worldE evan@cosocial.caE 2 Replies Last reply
                                        0
                                        • evan@cosocial.caE evan@cosocial.ca

                                          @cwebber @kopper @hongminhee I talk about this in my book. Unless the receiving user is online at the time the server receives the Announce, it's ridiculous to fetch the content immediately. Receiving servers should pause a random number of minutes and then fetch the content. It avoids the thundering herd problem.

                                          cwebber@social.coopC This user is from outside of this forum
                                          cwebber@social.coopC This user is from outside of this forum
                                          cwebber@social.coop
                                          wrote last edited by
                                          #126

                                          @evan @kopper @hongminhee But that means either:

                                          - Users don't get to see content that has been federated to them for *minutes*
                                          - Unless we show unverified messages, allowing for windows of impersonation attacks, in which substantial reputational damage can be done!

                                          And also:

                                          - Whenever I boost several of @vv's posts, her server can be down *for a while*. Random delays can help reduce load but not as substantially as signature verification
                                          - This has to be done for both the activity *and* the object
                                          - And there's no reason to include either the activity or the object if you care about not risking impersonation attacks, because you might as well just send {"@id": "https://example.org/post/12345/"}

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