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
Well, actually… big instances like kbin.social (but that is the same with other big instances or software), need to process not only the outbox but also the inbox of the activitypub. So this thread with comments, need to be sent to several instances. And each instance need to process this comment now. And the other way around is also true, I created this thread but that needed to be sent towards multiple instances (which is converted the inbox from their server perspective). Kbin.social had mainly issues with sending out messages actually (the outbox), because many instances are not responding or are blocked, causing retries and eventually also an increase in the queue.