My home instance is shutting down soon.

https://lemm.ee/post/65824884.

I am slightly unclear about what the instance admin meant.

Because of how Lemmy is built, everything posted on lemm.ee will still be accessible from other instances, even after we go offline.

How are other Lemmy instance able to access the content from the post-shutdown lemm.ee?

Do all the other Lemmy instances keep a copy of the content from lemm.ee?

If so, wouldn’t that be rather taxing on each Lemmy instance? (since they have to keep a copy of all the content from all instances they federate with).

I tried reading this up by researching on Lemmy federation, but this is still unclear to me.

  • Xylight@lemdro.id
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    19 hours ago

    The way ActivityPub federation works, once an instance is “linked” (like lemm.ee linking with lemmy.world, lemdro.id, etc), the instance will now send them an event once a post is made or something like that.

    For example:

    • lemm.ee —links–> lemmy.world
    • lemm.ee user makes a post A
    • lemm.ee —notifies–> lemmy.world
    • lemmy.world makes a copy of post A.

    So yes, every Lemmy instance stores copies of new data from other instances once they link.

    • TrivialKin@lemm.eeOP
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      18 hours ago

      every Lemmy instance stores copies of new data

      What about the old data? Are they also stored retroactively once the link happens?

      And about the linking, from what I gather, (taking your example) as long as any one user from lemmy.world from retrieves posts from lemm.ee, or if they subscribe to it, the “link” will happen. Is that correct?

      Is there anyway to verify that the data is persisted on lemmy.world? As long as the post/community is visible right now from lemmy.world, would it be indication that it will be there even after lemm.ee shuts down?

      Basically, I am mainly concerned whether my previous content on lemm.ee will be persisted.

      • Mark with a Z@lemmy.kde.social
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        18 hours ago

        When instances federate, they don’t send old content. Old content will be fetched if a user tries to open it, for example by clicking a link to an old post (on some apps) or pasting its url into the search box.

        The data copied to the other instance will stay on the other instance, unless manually deleted for some reason.

      • Rentlar@lemmy.ca
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        18 hours ago

        So if a brand new instance is started, it does not retroactively receive any content from other servers. Only ones that were connected by a link at the time content was posted will have a copy, essentially.

        To know which posts will be kept on different servers, look up your own username, e.g. https://lemmy.ca/u/[email protected]