Kichae does the category show as having followers? (If the remote category doesn't have followers there will be a little warning note before the topic list.)

I do have a few categories I follow here and they seem to be working, though they may not be Lemmy specifically.

Was science@mander.xyz one of them?

julian No, science@mander.xyz isn't currently being followed, and it shows the warning, but all of the ones in the screen shot above are from this forum, are being followed by me, and haven't received a new topic in 8 days. science_memes@mander.xyz, in particular, is almost hyper active right now.

Kichae thanks, I'll take a look ASAP

New observation: I'm still receiving notifications for up/down votes from Lemmy, but no other content.

Hmm... I am not sure whether it is significant, but I am still getting topics from one of my communities. That's why I was not aware that federation was broken.

It does suggest that it's a NodeBB-specific bug though...

I tested on a dev instance with a lemmy test group and found nothing wrong. Two-way posts work, as do upvotes.

I can definitely confirm that followed communities here aren't working, which is concerning. Not sure why yet.

After more debugging today I am less convinced that this is a NodeBB issue.

I am finding Lemmy communities where federation continues without issue, and others where there is no activity at all.

The sequence of events is:

1. NodeBB sends out a Follow
2. Lemmy responds with a 200 or equivalent
3. Lemmy later sends me an Accept
4. Lemmy later sends content (posts, upvotes, etc.)

startrek.website and ani.social both do everything ok.

lemmy.world and mander.xyz fail at step 3, and existing connections (where step 3 completed in the past) do not execute step 4. I literally am not seeing anything besides Like activities coming from those servers.

Existing PieFed and NodeBB integrations continue to work without issue.

julian@community.nodebb.org I'm actually having trouble getting new ani.social posts into my instance. I'm not sure if kichae@community.nodebb.org is having the same problem, but it seems that it grabbed posts from up to 9 days ago, and then stopped federating them in.

It says Asserting 0 group(s) when I check the remote category on my instance directly though, so perhaps this is related?

@julian On my implementation, I have not received anything actionable from a lemmy instance recently, but I purge remote posts after about a week. So this may not be NodeBB related. I am following some lemmy.world and lemmy.zip communities. The last federated lemmy activity I received originated at lemmy.ca 4 days, 19 hours ago.

Kichae I suppose it's worth rolling back to 4.3 and figuring out what the change was...! I just wish testing federation wasn't such a long process.

It is rather silly that it inter-platform federation so damn fragile. I can't wait until there's a bigger network of nodeBB sites federating.

Confirming that follow-unfollow-follow-unfollow logic is working as expected against ani.social which means the plumbing actually works.

arachnibot@nodebb.arachnibot.com did you update NodeBB 9 days ago?

julian@community.nodebb.org not to my knowledge! I actually reset my instance within the past 7 days, so it's unlikely to be that if I'd guess. It could be an upgrade related script didn't fire, but that's pure speculation

Kichae I ended up opening up an issue on the Lemmy repo and they pointed out that there hasn't been a loss of federation with Lemmy, but that something (likely on the NodeBB end) is throwing errors and causing Lemmy to defer sending activities until after some timeout.

Loss of communication from Lemmy · Issue #5722 · LemmyNet/lemmy

I apologize in advance because this issue is absolutely vague as hell, but I will try to be as thorough and succinct as possible. I am receiving reports that an existing NodeBB connection to Lemmy is severed or becomes unreliable after a...

GitHub (github.com)

With the Lemmy developers' help, we figured it out! It was NodeBB's spam protection mechanism. One of our configurable options is to limit the number of upvotes one can make per day.

1. Someone (or someones) on Lemmy communities was sending lots of upvotes and running into this limitation when those activities were propagated to NodeBB.
2. NodeBB dutifully noted this and sent back an HTTP 500.
3. Lemmy dutifully noted this and retried sending the activity using an exponential backoff algorithm
4. Eventually enough 500s were recorded that Lemmy decided that our server needed a time-out of sorts

I updated the code to handle this case better, and now the activities are coming in at full speed. It'll take awhile to get back up to sync though