Bug in ActivityPub

Tue, 22 Nov 2022 10:41:24 +0100

adminsforum@hubzilla.org

Nolan wrote the following post Tue, 22 Nov 2022 10:41:10 +0100

Bug in ActivityPub

I wrote this post: #^https://ein-hub-von-vielen.de/item/882d4404-48cb-4b81-b68f-98f9d015a82c where I mentioned @Pierre
Yet, in the distribution report, nothing is sent to mastouille.fr (@Pierre's instance)
And my comment doesn't appear on #^https://mastouille.fr/@Pierre67/109383766046641102

Is there already an opened issue about this bug?

show all 26 comments

Tue, 22 Nov 2022 11:11:53 +0100

Mario Vavti

mario@hub.somaton.com

Hubzilla currently does not send comments to anyone mentioned or everybody in the conversation. It sends comments to the thread owner (top level post author) and relies on them to relay the comments to their audience. This is because Hubzilla does not know (and probably should not from a orivacy point of view) who the audience ofthe toplevel post is.

Tue, 22 Nov 2022 11:50:23 +0100

Jupiter Rowland

jupiter_rowland@hub.netzgemeinde.eu

So basically, mentioning people Mastodon-style in a thread started on Mastodon is not only unnecessary but actually useless because only the thread starter receives the reply?

If Hubzilla ignores mentions in comments by design, this amounts to quite a big difference in how threads are handled on Mastodon (as actual discussion threads) and Hubzilla (as comments on a blog post). This should be in the end user manual.

On the other hand, Hubzilla does have a button for replying to specific comments. If the above is the case, this button is pretty useless, and there should be one for the start post instead.

Tue, 22 Nov 2022 12:05:46 +0100

Mario Vavti

mario@hub.somaton.com

@Jupiter Rowland mentioning them will give them a notification if they get the message. In this case i think #^https://mastidon.top should have relayed @Nolans comment to #^https://mastouille.fr which it obviously did not.

It is not s bug per se. Just different expecations between platforms and federation models. The ActivityPub protocol does not say anything about messages flow...

Tue, 22 Nov 2022 12:06:46 +0100

Jupiter Rowland

jupiter_rowland@hub.netzgemeinde.eu

/help/member/member_guide

Tue, 22 Nov 2022 12:37:06 +0100

Grischa

grischa@hub.brockha.us

@Mario Vavti

Hubzilla currently does not send comments to anyone mentioned or everybody in the conversation. It sends comments to the thread owner (top level post author) and relies on them to relay the comments to their audience.

Is this behavior something that most AP software manage the same and only mastodon differs or is it something hubzilla only does like this? If other software does not relay but depends on sender doing the job to send to mentions, it at least feels like a bug on hubzillas site, doesn't it?

This is because Hubzilla does not know (and probably should not from a orivacy point of view) who the audience ofthe toplevel post is.

Well, but when a comment with mention is written on the hubzilla instance, the instance knows already about person mentioned.. What privacy problem do you mean? You don't need to know the complete audience of the toplevel post. The comment shout be sent to the toplevel author and any account mentioned in the comment only (imho).

Tue, 22 Nov 2022 12:45:55 +0100

Mario Vavti

mario@hub.somaton.com

@Nolan

Does somethin in #activitypub forbid it?

No, it is not forbidden. It is just that you can not compare the federation models of Hubzilla and Mastodon. It can be fixed in Hubzilla but it can also be fixed in Mastodon. And most important, there is no right or wrong. It is a deficiency in the ActivityPub protocol imho.

Tue, 22 Nov 2022 13:04:57 +0100

Mario Vavti

mario@hub.somaton.com

@Grischa

You don't need to know the complete audience of the toplevel post.

This way the rest of the audience will not get the complete conversation. And this is one of the reasons why we think that the thread owner should relay the comments.

Tue, 22 Nov 2022 13:14:28 +0100

Scott M. Stolz

scott@hubzilla.monster

My understanding, as it was explained to me, is that we have to do it that way because of how Mastodon distributes posts and comments.

If you send it to the thread owner, Mastodon will send the comment to anyone following their thread.

When you try to send comments directly to users, if they are not following you, they probably won't see it.

At least that is my understanding. Correct me if I am wrong.

Tue, 22 Nov 2022 13:18:40 +0100

Malendur

malendur8944@hub.art3mis.de

And most important, there is no right or wrong

According to Nolan's testcase, this behaviour is obvilousy wrong.
Because as said @Jupiter Rowland, the main purpose of mentions (from a user point of view) is to notify the mentioned user.

This way the rest of the audience will not get the complete conversation.

OK, not a problem: as long as all mentioned users get the message it is find. See this as private messages if you want.

One more reason to not relay on thread owner relay: the owner instance could have blocked the mentioned user's instance, and will absolutly not relay to him the message. But we, as Hubzilla users, have zero way to know that. This result, as said @Nolan, to "random behavior", which is the worst behavior for an average user...

Tue, 22 Nov 2022 13:22:19 +0100

Einer von Vielen

einer@digitalesparadies.de

@Nolan (nolan@ein-hub-von-vielen.de) offtopic: ein-hub-von-vielen.de is a private server. The registration was open by accident for some time. I do not want to say anything. This is just an information. I would recommend to have a clone. This server is also used to test certain addons. This might result in high CPU load and slow response times in the weeks to come.

Tue, 22 Nov 2022 13:24:10 +0100

emaxmax

emaxmax@hub.netzgemeinde.eu

@Mario Vavti

It is a deficiency in the ActivityPub protocol imho.

Then override this deficiency with, on purpose, sending the message to mentioned users. That way you'll have a consistent process.

My understanding, as it was explained to me, is that we have to do it that way because of how Mastodon distributes posts and comments.

Sending explicitly the message won't change the default Mastodon process. I can't see what could go wrong (except maybe double msg (to be confirmed!), but that already happends with boosts...)

Tue, 22 Nov 2022 13:25:41 +0100

Grischa

grischa@hub.brockha.us

@Mario Vavti

This way the rest of the audience will not get the complete conversation. And this is one of the reasons why we think that the thread owner should relay the comments.

Well but exactly this is what I see from other AP hosts, if I am not totally misunderstanding things. I don't get all comments in a thread always, but I get the comments I am mentioned in at least. Isn't that better then getting no comment although mentioned?

As far I have seen how it works on "other" AP instances (I am using Pleroma, Friendica and rarely Mastodon beside of Hubzilla): I get all comments I am mentioned in and all comments of users I follow. These two options seem to be "safe". But in most cases I get even more (I don't know from what "rule").

Tue, 22 Nov 2022 14:03:30 +0100

Mario Vavti

mario@hub.somaton.com

@Malendur

According to Nolan's testcase, this behaviour is obvilousy wrong.

As already mentioned: not wrong, just a different set of expectations :wink:

Tue, 22 Nov 2022 14:07:10 +0100

Mario Vavti

mario@hub.somaton.com

@Grischa

These two options seem to be "safe".

Well, as long as the post is public...

Tue, 22 Nov 2022 14:10:25 +0100

Mario Vavti

mario@hub.somaton.com

@Malendur

One more reason to not relay on thread owner relay: the owner instance could have blocked the mentioned user's instance, and will absolutly not relay to him the message.

Possibly not relaying for a good reason then? It is the thread owners thread...

Tue, 22 Nov 2022 14:35:12 +0100

emaxmax

emaxmax@hub.netzgemeinde.eu

@Mario Vavti

Well, as long as the post is public...

Granted. But Hubzilla has this information, so that's not blocking.

Tue, 22 Nov 2022 17:25:20 +0100

emaxmax

emaxmax@hub.netzgemeinde.eu

@Mario Vavti No. In Mastodon's world, blocking is to prevent the blocked instance to "write" (comment, spam). It's not to block "reading" (which would be stupid as the posts are public, and anyone can read them directly on the instance)

Tue, 22 Nov 2022 17:45:17 +0100

RockyIII

rocky3@im.allmendenetz.de

@Nolan
now you post reached the thread

https://mastodon.top/@Sandrousseau/109382468824174465

Tue, 22 Nov 2022 18:37:43 +0100

Jupiter Rowland

jupiter_rowland@hub.netzgemeinde.eu

@RockyIII So it was just a case of an overloaded Mastodon instance?

We should keep an eye on this regardless. That said, the functionality of commenting on Mastodon toots from Hubzilla isn't too bad. I know from personal experience that if you comment on a Mastodon toot from Hubzilla, and someone on Mastodon likes your comment, the like appears here as a thumb up.

Maybe it's really just slow sometimes.

Tue, 22 Nov 2022 18:38:46 +0100

Malendur

malendur8944@hub.art3mis.de

@RockyIII Indeed. But for instance my post #^https://ussr.win/item/3e8aef64-eed1-45c6-8fa9-82e74596a314 (24h hours old) still doesn't appears in the original post #^https://respublicae.eu/@KarimaDelli/109377189314277000 and was not sent to @Sandrine Rousseau.
Randomness and inconstancy are really the worst scenario...

Sun, 11 Dec 2022 10:24:04 +0100

Mike Macgirvin

mike@macgirvin.com

Bob starts a conversation. He makes it private - including only Alice and Eve. Alice replies. She mentions @judy. Here's the problem - it is Bob's conversation and he didn't invite Judy. Now all of a sudden she's in the conversation.

In Hubzilla, Judy will not receive a mention notification. In Streams and some later works, she'll receive a notification only if the conversation is public. Mastodon allows you to mention somebody in a private conversation and bring them into somebody else's private conversation. So it isn't really private, is it?

Sun, 11 Dec 2022 11:56:19 +0100

Scott M. Stolz

scott@hubzilla.monster

I have noticed some weird variations between Mastodon instances. Since I just started connecting with people on Mastodon, I have been going to their Mastodon profile to see if my like, follows, and comments are appearing. Sometimes they do, and sometimes they don't.

One thing I noticed is that not all of them are running the same version, and I wonder if there may be a difference there.

Tue, 17 Jan 2023 21:29:29 +0100

Scott M. Stolz

scott@hubzilla.monster

Even with Mastodon instances running the latest version, I don't always get the whole conversation. I've seen situations where I'll get one comment from a person, but then not see their second comment on the same thread. It's very odd. So it's likely a delivery issue, not permissions.

Wed, 18 Jan 2023 22:15:49 +0100

Jupiter Rowland

jupiter_rowland@hub.netzgemeinde.eu

I've noticed a few things.

First, if you want to reply to a toot that isn't a reply already, you have to mention at least the original poster. The mentioning won't be visible on #Mastodon. If you reply to a reply, you may be lucky enough not to need to mention anyone.

Otherwise, it seems rather random which makes it from #Hubzilla to Mastodon or vice versa. I've seen a reply from Mastodon to one of my posts be visible to another one of my channels under the same account, but not to "myself".

I've been notified (in-world!) by someone that she has sent me a direct message from Mastodon which I've never received. And I'm slowly but steadily getting doubts that this has anything to do with whitelist filtering.

Thu, 19 Jan 2023 03:04:00 +0100

Scott M. Stolz

scott@hubzilla.monster

At this point, ActivityPub communications with Mastodon are so inconsistent, that I will only run it on personal hubs. When I open up Complete Hosting Guide as a public hub that anyone can sign up for, I think I might keep ActivityPub off. I don't think it gives a good user experience at this point.

Fri, 23 Jun 2023 03:37:22 +0200

emaxmax

emaxmax@hub.netzgemeinde.eu

@Altyr on Stream So..... is there a opened issue for the backport to #hubzilla?