Post by @artyom@piefed.social

2026-10-20 02:10 UTC

TIL the fediverse basically DDOS's sites when you share a link. I shared a link from NPR Tiny Desk but there was no image preview or video embed. After investigating this I learned that when you do that, each instance picks up the link and individually retrieves the link preview nearly simultaneously. For gargantuan sites like YT or Reddit, this is a trivial amount of traffic and not a problem, but for smaller sites like NPR this results in a sort of botnet DDOS attack on the site’s servers. More here. Another example here . For that reason, NPR has blocked Fediverse servers like Mastodon. I have experienced this on my personal server as well (DDOS), but at the time didn’t know why, exactly. This isn’t the end of the world, but certainly is not great and hurts engagement with the content. Is there a solution for this? Perhaps using some sort of webtorrent service like PeerTube where they just fetch the information from another fediverse server instead of the source server? Maybe fetching embeds client-side? At least that would stagger the requests. E: Many people have replied comparing this to the Reddit “hug of death” or “The Slashdot effect”. This is not the same at all. Those are legitimate site visits from humans that happen over the course of several hours. This is the result of several thousand servers all automatically fetching the same image simultaneously , and without any human involvement, and potentially next to zero human traffic to the site, which is why I compared it to a botnet or DDOS attack.

Replies (10)

@wjs018@piefed.wjs018.xyz 2026-10-20 02:28

There are two proposed solutions I have seen. I do not claim that this is exhaustive, just only limited to the proposals that I have stumbled across. FASP - Fediverse Auxiliary Service Provider The idea that mastodon has is to have a third-party service that does something like generate a link preview once and then share that to fediverse instances that need it. They have a whole spec they wrote up about these kinds of services that can be run to help out fediverse instances with different things like this, search, or discoverability. They call these FASPs - the repo with the spec is here. I don’t yet know of any FASP that is live and running, so it is kind of a paper spec at the moment. I don’t do too much on the microblogging side of the fediverse though, so I very well could be wrong. Federate link metadata and the post at the same time This comes from an issue on PieFed’s repo. It is basically just an idea at this point, but it is a pretty basic one; have the originating instance fetch the link preview information and simply federate it out alongside the post itself.

Open ##5264997
@TropicalDingdong@lemmy.world 2026-10-20 02:25

smaller sites like NPR

Open ##5265028
@frongt@lemmy.zip 2026-10-20 02:55

A slight delay would be perfectly sufficient.

Open ##5265884
@ieightpi@lemmy.world 2026-10-20 04:12

This probably why my place of work blocked it behind the firewall

Open ##5266882
@cybervegan@lemmy.world 2026-10-20 12:13

I have my blog address (which goes to my home server) in my Mastodon profile, and every time I post on Masto, my server gets a request from every Mastodon site that federates with my instance - i.e. hundreds of requests. It’s no problem for my server, because my blog is a static site, but for anything that dynamically generates every single page impression (like worpress or joomla), it could be a problem. Caching settings might help, I suppose. Truth is, though, I get far more traffic from vulnerability scanners and AI crawlers that don’t honour robots.txt (or aren’t yet listed).

Open ##5272832
@Pamasich@kbin.earth 2026-10-20 08:25

I don't really get it. The image is federated, there's no need for instances to refetch it. Just checked out some posts and indeed it's there, in the image property. With the URL pointing to the Lemmy instance. So if this is actually an issue, that's just bad programming and needs to be fixed. Edit: didn't notice OP uses Piefed. Unlike Lemmy and Mbin, it seems like Piefed doesn't federate it. Edit: actually I'm blind, Piefed does federate it too, sorry piefed

Open ##5273034
@GenosseFlosse@feddit.org 2026-10-20 13:01

Is there a reason why the publishing instance is not downloading the preview image, and then submits it with the post to the other instances? This way they would not have to fetch it themselves.

Open ##5274218
@ByteJunk@lemmy.world 2026-10-20 07:54

I mean, just how many instances are gonna ping the URL? Several hundred, low thousands at worst? Unless it happens to be some very large media content or a dynamic page with no caching, I’d think the automated federation hits shouldn’t be too bad. The influx of users that might come after a viral post though, that’s rough…

Open ##5279585
@AdrianTheFrog@lemmy.world 2026-10-21 03:29

it seems like ideally it shouldn’t attempt to preview the link before a user tries to view the content. i guess that would increase latency for users though

Open ##5280759
@yuki2501@lemmy.world 2026-10-22 01:00

Heh. Ever heard of the Slashdot effect?

Open ##5306269