Today kbin.social is blocking a huge list of domains just to get federation working again.
The reason for this temporally block is not to defederate, but rather to get the large backlog of 500k messenger queue processed again. Anyway, this does mean that kbin.social is federating again with other instances.
This is a temporary measure. Several users / developers are looking into how to better optimize the failed message queue, as we speak. Hopefully Ernest has eventually time to dive into solutions as well instead of workarounds, once his instance is migrated to Kubernets. See my preview thread: https://kbin.melroy.org/m/updates/t/4257/Kbin-federation-issues-and-infra-upgrade
List of the domains causing trouble:
lemmygrad.ml, eientei.org, vive.im, lemmy.ml, lemmynsfw.com, kbin.lol, lemmy.webgirand.eu, tuna.cat, posta.no, lemmy.atay.dev, sh.itjust.works, kbin.stuffie.club, kbin.dssc.io, bolha.social, dataterm.digital, kbindev.lerman-development.com, test.fedia.io, mer.thekittysays.icu, lemmy.stark-enterprise.net, kbin.rocks, kbin.cocopoops.com, kbin.lgbt, lemmy.deev.io, lemmy.lucaslower.com, lemmy.norbz.org, social.jrruethe.info, digitalgoblin.uk, pwzle.com, lemmy.friheter.com, federated.ninja, lemmy.shtuf.eu, u.fail, arathe.net, lemmy.click, thekittysays.icu, lemmy.ubergeek77.chat, lemmy.maatwo.com, faux.moe, eslemmy.es, seriously.iamincredibly.gay, test.dataharvest.social, programming.dev, kbin.knocknet.net, pawb.social, lucitt.social, longley.ws, kbin.dentora.social, atay.dev, lemmy.kozow.com, ck.altsoshl.com, pawoo.net, techy.news, lemmy.vergaberecht-kanzlei.de, lemmyonline.com, beehaw.org, pouet.chapril.org, kbin.pcft.eu, fl0w.cc, lemmy.sdf.org, lemmy.zip, feddit.dk, fedi.shadowtoot.world, lemmy.noogs.me, lemmy.kemomimi.fans, social.agnitum.co.uk, fediverse.boo, hive.atlanten.se, forkk.me, lemmy.ghostplanet.org, lemmy.mayes.io, lemmy.mats.ooo, lemmy.world, lemmy.sdfeu.org, lemmy.death916.xyz, geddit.social, masto.fediv.eu
I'm surprised to see lemmy.sdf.org on the list of domains causing trouble when it only has 2.7k users. Growing pains is weird lol
Actually in that case it's not the amount of users. But the downtime of that server yesterday, causing a spike in queued messages on kbin.social.
See errors: https://fediverse.observer/lemmy.sdf.org
Or.. it could be that lemmy.sdf.org blocked kbin.social.. Which is also possible, but I can't verify this. I can only confirm that https://lemmy.ml is actively blocking all kbin instances, based on user-agent strings.