I’ve set up a Lemmy instance and tested federation by commenting with my Mastodon account on the lemmy instance, which worked.

But I broke the test instance and had to start over (not even once).

The productive instance runs now, but after a few days I figured out that there is still the old post from the old installation on Mastodon and over Mastodon I can’t see the new post and no new comments?

It is the same link (older Mastodon post, old Mastodon post, new Lemmy post), but the content is different.

  • The post itself doesn’t update (it is completely different)
  • The comments don’t update (different comments)

How to solve this problem? Is it even solvable?

    • maxmoonOP
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      1 year ago

      Might it be a good idea to to just copy the post so it gets a higher ID, which wasn’t used before? Because the productive system is already running and has a lot of content and a new reinstall might even block more IDs.

      • RoundSparrow
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        1 year ago

        if it were me right now with Lemmy 0.18.4, I’d take the server offline, do a PostgreSQL dump file - keep a copy, then hand-edit the sequence numbers in the dump file - and do a restore.

        you probably only had a few users, so I would set user to 100, person id can be higher because of federation - but jump ahead to 10000 maybe. Post and comment set ahead to 10000 … and community set ahead to 10000 because that gets federated

        the PostgreSQL sequence numbers should only get used on newly created objects here-forward.

        • maxmoonOP
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          1 year ago

          That sounds complicated and I am afraid something could break (again). The last days I tried to fix something in the db, which led to other problems.

          • RoundSparrow
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            1 year ago

            It is complicated. It’s surely a damned-if-do damned-if-don’t situation. It doesn’t sound like you had all that much in terms of local users, communities, posts, comments - so at least that’s in your favor.

            • maxmoonOP
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              1 year ago

              I tried to copy some posts, but it looks like it is totally screwed up, now. Even higher ids show wrong content on some Mastodon instances, even if I am sure I only did a few tests with posts.

              Only way to solve this (imho) is to reinstall Lemmy BUT use another subdomain.

              What do you think? Will this work?

              • RoundSparrow
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                1 year ago

                Only way to solve this (imho) is to reinstall Lemmy BUT use another subdomain.

                I wold agree that this is worth considering as an approach to not clash identity and get into custom SQL or Rust programming. But there isn’t even really a procedure in place to decommission the old lemmy entity… so another damned if you do, damned if you don’t in 0.18.4 era.

                I’m a little surprised that the federation private key/public key signing doesn’t get upset about all new keys appearing on the same domain name. I’ve tried to get details of exactly how a server joins the Lemmy network and gets discovered over on !lemmyfederation@lemmy.ml but haven’t gotten any actually discussion on the details.

                What do you think? Will this work?

                I’ve seen people nuke and start-over their database from empty several times while having problems setting up NGinx and Docker… or whatever part.

                I’m glancing at the list of SEQUENCE in Lemmy…

                CREATE SEQUENCE public.admin_purge_comment_id_seq
                CREATE SEQUENCE public.admin_purge_community_id_seq
                CREATE SEQUENCE public.admin_purge_person_id_seq
                CREATE SEQUENCE public.admin_purge_post_id_seq
                CREATE SEQUENCE public.captcha_answer_id_seq
                CREATE SEQUENCE public.comment_aggregates_id_seq
                CREATE SEQUENCE public.comment_id_seq
                CREATE SEQUENCE public.comment_like_id_seq
                CREATE SEQUENCE public.comment_reply_id_seq
                CREATE SEQUENCE public.comment_report_id_seq
                CREATE SEQUENCE public.comment_saved_id_seq
                CREATE SEQUENCE public.community_aggregates_id_seq
                CREATE SEQUENCE public.community_block_id_seq
                CREATE SEQUENCE public.community_follower_id_seq
                CREATE SEQUENCE public.community_id_seq
                CREATE SEQUENCE public.community_language_id_seq
                CREATE SEQUENCE public.community_moderator_id_seq
                CREATE SEQUENCE public.community_person_ban_id_seq
                CREATE SEQUENCE public.custom_emoji_id_seq
                CREATE SEQUENCE public.custom_emoji_keyword_id_seq
                CREATE SEQUENCE public.email_verification_id_seq
                CREATE SEQUENCE public.federation_allowlist_id_seq
                CREATE SEQUENCE public.federation_blocklist_id_seq
                CREATE SEQUENCE public.instance_id_seq
                CREATE SEQUENCE public.language_id_seq
                CREATE SEQUENCE public.local_site_id_seq
                CREATE SEQUENCE public.local_site_rate_limit_id_seq
                CREATE SEQUENCE public.local_user_id_seq
                CREATE SEQUENCE public.local_user_language_id_seq
                CREATE SEQUENCE public.mod_add_community_id_seq
                CREATE SEQUENCE public.mod_add_id_seq
                CREATE SEQUENCE public.mod_ban_from_community_id_seq
                CREATE SEQUENCE public.mod_ban_id_seq
                CREATE SEQUENCE public.mod_hide_community_id_seq
                CREATE SEQUENCE public.mod_lock_post_id_seq
                CREATE SEQUENCE public.mod_remove_comment_id_seq
                CREATE SEQUENCE public.mod_remove_community_id_seq
                CREATE SEQUENCE public.mod_remove_post_id_seq
                CREATE SEQUENCE public.mod_sticky_post_id_seq
                CREATE SEQUENCE public.mod_transfer_community_id_seq
                CREATE SEQUENCE public.password_reset_request_id_seq
                CREATE SEQUENCE public.person_aggregates_id_seq
                CREATE SEQUENCE public.person_ban_id_seq
                CREATE SEQUENCE public.person_block_id_seq
                CREATE SEQUENCE public.person_follower_id_seq
                CREATE SEQUENCE public.person_id_seq
                CREATE SEQUENCE public.person_mention_id_seq
                CREATE SEQUENCE public.person_post_aggregates_id_seq
                CREATE SEQUENCE public.post_aggregates_id_seq
                CREATE SEQUENCE public.post_id_seq
                CREATE SEQUENCE public.post_like_id_seq
                CREATE SEQUENCE public.post_read_id_seq
                CREATE SEQUENCE public.post_report_id_seq
                CREATE SEQUENCE public.post_saved_id_seq
                CREATE SEQUENCE public.private_message_id_seq
                CREATE SEQUENCE public.private_message_report_id_seq
                CREATE SEQUENCE public.received_activity_id_seq
                CREATE SEQUENCE public.registration_application_id_seq
                CREATE SEQUENCE public.secret_id_seq
                CREATE SEQUENCE public.sent_activity_id_seq
                CREATE SEQUENCE public.site_aggregates_id_seq
                CREATE SEQUENCE public.site_id_seq
                CREATE SEQUENCE public.site_language_id_seq
                CREATE SEQUENCE public.tagline_id_seq
                CREATE SEQUENCE utils.deps_saved_ddl_id_seq