Hi @angus, I can't be certain about what is actually happening, which needs an admin and knowledgeable person with the ActivityPub plugin, but I observe that this forum becomes slow or even unreachable at times and it looks to be related somehow to posts that are being federated. Notified about that…

I also noticed that SH becomes unresponsive when I publish a reply. This is because replies are delivered to many other servers, which start to load the reply tree, all at once. Sorry about that

if this is the case, then it is basically a "thundering herd" issue similar to how link previews can cause issues. to which the mitigation is that softwares should stop auto-fetching resources that might not ever be seen, and to instead use on-demand deferred "lazy loading" strategies.

I disable my plugin for that trouble I’ve received many request no stop from the same souce-instance or many others instances making the same type of request without none delay limit, sorry but this is weird all time requesting and flooding my server is too much.

angus: Hey guys, I’ll have a closer look at this soon, hopefully tomorrow. I don’t want to put pressure, and it may be inconvenient time now in the Summer vacation period, but if you have an opportunity to delve into the issue it would be great. Right now a single federated post may make the forum v…

Hey guys, if this is causing serious issues, I would note there a number of tools already in the plugin a community admin can use for this kind of scenario. There is comprehensive logging, including object logging, you can use to determine the source of any troublesome actors. activity_pub_verb…

Ok, SocialHub loaded, I fired up the logs and the culprit seems relatively clear. [Screenshot 2025-08-10 at 16.54.34] I’d suggest adding mastodon.sdf.org to the blocklist and sending a note to their admins that they’re spamming socialhub. *edit It seems another issue was that signed requests had…

Thanks for your quick reply, @angus. I am just a regular member of this forum, but this looks to be useful info for @how or other forum admins to look into.

No worries. I suspect simply enabling signed requests and adding mastodon.sdf.org to the blocklist is all that is needed.

[image] angus: I’d suggest adding mastodon.sdf.org to the blocklist It should block everywhere. It acts as a DDOS-agent. Amount of requests it does is totally horrible.

AP processing dragging forum down?

Support

angus (Angus McLeod) July 15, 2025, 7:55am 4

Hey guys, I’ll have a closer look at this soon, hopefully tomorrow.

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Why are supposedly ActivityPub-federated Discourse threads inaccessible via external AP clients? Bug activitypub	15	385	May 20, 2025

AP processing dragging forum down?

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