I realise this is a known issue and that lemmy.world isn’t the only instance that does this. Also, I’m aware that there are other things affecting federation. But I’m seeing some things not federate, and can’t help thinking that things would be going smoother if all the output from the biggest lemmy instance wasn’t 50% spam.
Hopefully this doesn’t seem like I’m shit-stirring, or trying to make the Issue I’m interested in more important than other Issues. It’s something I mention occasionally, but it might be a bit abstract if you’re not the admin of another instance.
The red terminal is a tail -f of the nginx log on my server. The green terminal is outputting some details from the ActivityPub JSON containing the Announce. You should be able to see the correlation between the lines in the nginx log, and lines from the activity, and that everything is duplicated.
This was generated by me commenting on an old post, using content that spawns an answer from a couple of bots, and then me upvoting the response. (so CREATE, CREATE, LIKE, is being announced as CREATE, CREATE, CREATE, CREATE, LIKE, LIKE). If you scale that up to every activity by every user, you’ll appreciate that LW is creating a lot of work for anyone else in the Fediverse, just to filter out the duplicates.
If it’s reproducible, you should file a bug report with Lemmy itself.
I can’t re-produce anything, because I don’t run Lemmy on my server. It’s possible to infer that’s it’s related to the software (because LW didn’t do this when it was on 0.18.5). However, it’s not something that, for example, lemmy.ml does. An admin on LW matrix chat suggested that it’s likely a combination of instance configuration and software changes, but a bug report from me (who has no idea how LW is set up) wouldn’t be much use.
I’d gently suggest that, if LW admins think it’s a configuration problem, they should talk to other Lemmy admins, and if they think Lemmy itself plays a role, they should talk to the devs. I could be wrong, but this has been happening for a while now, and I don’t get the sense that anyone is talking to anyone about it.
You can still make a bug report, so that somebody with the actual means can look into it. If every action is duplicated that’d be pretty severe, if not, well it’ll be closed.
A bug report for software I don’t run, and so can’t reproduce would be closed anyway. I think ‘steps to reproduce’ is pretty much the first line in a bug report.
If I ran a server that used someone else’s software to allow users to download a file, and someone told me that every 2nd byte needed to be discarded, I like to think I’d investigate and contact the software vendors if required. I wouldn’t tell the user that it’s something they should be doing. I feel like I’m the user in this scenario.
Idk, it’s FOSS, so you could always try, but just complaining and hoping somebody picks up on it probably also works. I don’t judge :)
I’ve since relented, and filed a bug
<3
Oooooo you sassin
It seems its a misconfiguration problem when running multiple server processes, which mostly is only done by larger instances. So it’s not a bug in lemmy per se, but perhaps a bug in lemmy.worlds configuration.
Is it a misconfiguration or a software bug?
When I’ve mentioned this issue to admins at lemmy.ca and endlesstalk.org (relevant posts here and here), they’ve suggested it’s a misconfiguration. When I said the same to lemmy.world admins (relevant comment here), they also suggested it was misconfig. I mentioned it again recently on the LW channel, and it was only then was Lemmy itself proposed as a problem. It happens on plenty of servers, but not all of them, so I don’t know where the fault lies.
Could it be something to do with an instance running multiple servers, i.e. for horizontal scaling? Maybe there’s some configuration problem where two servers are sending out the federation rather than just one.
Obviously if you only run one lemmy process (which I think most smaller instances do) then it’s not a problem. But if you run more (which I’d assume lemmy.world does) then it could perhaps be the reason.
EDIT: Probably should’ve checked your links first as that seems to be exactly what is happening lol
I’m only running one process, I’d assume the problem isn’t happening for Feddit.dk.
Yeah, that’s the conclusion I came away with from the lemmy.ca and endlesstalk.org chats. That’s it due to multiple docker containers. In the LW Matrix room though, an admin said he saw one container send the same activity out 3 times. Also, LW were presumably running multiple containers with 0.18.5, when it didn’t happen, so it maybe that multiple containers is only part of the problem.
I’m not surprised that it changed from 0.18.5 as the way that you spread the federation queue out changed significantly from that version to 0.19.
All the information is here but if you just run the same configuration as before 0.19, then you will have trouble.
Update: for LW, this behaviour stopped around about Friday 12th April. Not sure what changed, but at least the biggest instance isn’t doing it anymore.
we’ve switched from using multiple federation sending containers (which are supposed to split receiving instances across workers) to just using a single one.
