It is probably due to a number of people stopping using their alts after some instance hopping.

Also a few people who came to see how it was, and weren’t attracted enough to become regular visitors.

Curious to see at which number we’ll stabilize.

Next peak will probably happen after either major features release (e.g. exhaustive mod tools allowing reluctant communities to move from Reddit) or the next Reddit fuck up (e.g. removing old.reddit)

Stats on each server: https://lemmy.fediverse.observer/list

  • Anony Moose
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    410 months ago

    Can you explain to me why it isn’t social hazing?

    Like I said, this was my interpretation based on reading that exchange. It’s difficult to convey tone or intention with text, but I didn’t detect hostility from the devs, but I did sense that they were frustrated that process wasn’t being followed. Perhaps they should not have gotten hung up on that, but it didn’t appear to be malicious.

    Do you know how to read a SQL statement? I just can’t grasp how it isn’t social hazing. I’ve been reading SQL statements for decades, this is obviously a problematic one.

    I do, and your arguments about the joins being problematic seemed solid. From having worked on systems with huge scale, I also agree that Lemmy doesn’t seem to be big enough to be brought to its knees by the volume of posts it’s processing. However, I’m far from an expert, so I don’t want to suggest any certainty about the root causes, especially as I don’t have the energy or inclination to dig as deep into it as I would to form that opinion.

    I don’t know why they weren’t receptive, but perhaps they themselves felt attacked. I know that wasn’t your intention, but misunderstanding happen, especially over text.

    • RoundSparrow
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      210 months ago

      Here, you can dig into what posted days before the pull request you read:

      https://github.com/LemmyNet/lemmy/issues/2877#issuecomment-1685314733

       

      June 4:

      joins are better than in queries with potentially thousands of inserted IDs.

      Given that more than 8 JOIN statements is something PostgreSQL specifically concerns itself with (join_collapse_limit). I hand-edit the query with a single IN clause and the performance problem disappears. 8 full seconds becomes less than 200ms against 5,431,043 posts. And that 200ms is still high, as I was extremely over-reaching with “LIMIT 1000” in case the end-user went wild with blocking lists or some other filtering before reaching the final “LIMIT 10”. When I change it to “LIMIT 20” in the subquery, it drops almost in half to 115ms… still meeting the needs of the outer “LIMIT 10” by double. More of the core query filtering can be put into the IN subquery, as we aren’t dealing with more than 500 length pages (currently limited to 50).

      SELECT 
         "post"."id" AS post_id, "post"."name" AS post_title,
         -- "post"."url", "post"."body", "post"."creator_id", "post"."community_id", "post"."removed", "post"."locked", "post"."published", "post"."updated", "post"."deleted", "post"."nsfw", "post"."embed_title", "post"."embed_description", "post"."thumbnail_url",
         -- "post"."ap_id", "post"."local", "post"."embed_video_url", "post"."language_id", "post"."featured_community", "post"."featured_local",
           "person"."id" AS p_id, "person"."name",
           -- "person"."display_name", "person"."avatar", "person"."banned", "person"."published", "person"."updated",
           -- "person"."actor_id", "person"."bio", "person"."local", "person"."private_key", "person"."public_key", "person"."last_refreshed_at", "person"."banner", "person"."deleted", "person"."inbox_url", "person"."shared_inbox_url", "person"."matrix_user_id", "person"."admin",
           -- "person"."bot_account", "person"."ban_expires",
           "person"."instance_id" AS p_inst,
         "community"."id" AS c_id, "community"."name" AS community_name,
         -- "community"."title", "community"."description", "community"."removed", "community"."published", "community"."updated", "community"."deleted",
         -- "community"."nsfw", "community"."actor_id", "community"."local", "community"."private_key", "community"."public_key", "community"."last_refreshed_at", "community"."icon", "community"."banner",
         -- "community"."followers_url", "community"."inbox_url", "community"."shared_inbox_url", "community"."hidden", "community"."posting_restricted_to_mods",
         "community"."instance_id" AS c_inst,
         -- "community"."moderators_url", "community"."featured_url",
           ("community_person_ban"."id" IS NOT NULL) AS ban,
         -- "post_aggregates"."id", "post_aggregates"."post_id", "post_aggregates"."comments", "post_aggregates"."score", "post_aggregates"."upvotes", "post_aggregates"."downvotes", "post_aggregates"."published",
         -- "post_aggregates"."newest_comment_time_necro", "post_aggregates"."newest_comment_time", "post_aggregates"."featured_community", "post_aggregates"."featured_local",
         --"post_aggregates"."hot_rank", "post_aggregates"."hot_rank_active", "post_aggregates"."community_id", "post_aggregates"."creator_id", "post_aggregates"."controversy_rank",
         --  "community_follower"."pending",
         ("post_saved"."id" IS NOT NULL) AS save,
         ("post_read"."id" IS NOT NULL) AS read,
         ("person_block"."id" IS NOT NULL) as block,
         "post_like"."score",
         coalesce(("post_aggregates"."comments" - "person_post_aggregates"."read_comments"), "post_aggregates"."comments") AS unread
      
      FROM (
         ((((((((((
         (
      	   (
      	   "post_aggregates" 
      	   INNER JOIN "person" ON ("post_aggregates"."creator_id" = "person"."id")
      	   )
         INNER JOIN "community" ON ("post_aggregates"."community_id" = "community"."id")
         )
         LEFT OUTER JOIN "community_person_ban"
             ON (("post_aggregates"."community_id" = "community_person_ban"."community_id") AND ("community_person_ban"."person_id" = "post_aggregates"."creator_id"))
         )
         INNER JOIN "post" ON ("post_aggregates"."post_id" = "post"."id")
         )
         LEFT OUTER JOIN "community_follower" ON (("post_aggregates"."community_id" = "community_follower"."community_id") AND ("community_follower"."person_id" = 3))
         )
         LEFT OUTER JOIN "community_moderator" ON (("post"."community_id" = "community_moderator"."community_id") AND ("community_moderator"."person_id" = 3))
         )
         LEFT OUTER JOIN "post_saved" ON (("post_aggregates"."post_id" = "post_saved"."post_id") AND ("post_saved"."person_id" = 3))
         )
         LEFT OUTER JOIN "post_read" ON (("post_aggregates"."post_id" = "post_read"."post_id") AND ("post_read"."person_id" = 3))
         )
         LEFT OUTER JOIN "person_block" ON (("post_aggregates"."creator_id" = "person_block"."target_id") AND ("person_block"."person_id" = 3))
         )
         LEFT OUTER JOIN "post_like" ON (("post_aggregates"."post_id" = "post_like"."post_id") AND ("post_like"."person_id" = 3))
         )
         LEFT OUTER JOIN "person_post_aggregates" ON (("post_aggregates"."post_id" = "person_post_aggregates"."post_id") AND ("person_post_aggregates"."person_id" = 3))
         )
         LEFT OUTER JOIN "community_block" ON (("post_aggregates"."community_id" = "community_block"."community_id") AND ("community_block"."person_id" = 3)))
         LEFT OUTER JOIN "local_user_language" ON (("post"."language_id" = "local_user_language"."language_id") AND ("local_user_language"."local_user_id" = 3))
         )
      WHERE 
        post_aggregates.id IN (
           SELECT id FROM post_aggregates
           WHERE "post_aggregates"."creator_id" = 3
           ORDER BY "post_aggregates"."featured_local" DESC , "post_aggregates"."published" DESC
           LIMIT 1000
        )
        AND
        (((((((
        (
        (("community"."deleted" = false) AND ("post"."deleted" = false))
        AND ("community"."removed" = false))
        AND ("post"."removed" = false)
        )
        AND ("post_aggregates"."creator_id" = 3)
        )
        AND ("post"."nsfw" = false))
        AND ("community"."nsfw" = false)
        )
        AND ("local_user_language"."language_id" IS NOT NULL)
        )
        AND ("community_block"."person_id" IS NULL)
        )
        AND ("person_block"."person_id" IS NULL)
        )
      ORDER BY "post_aggregates"."featured_local" DESC , "post_aggregates"."published" DESC
      LIMIT 10
      OFFSET 0
      ;
      

       

      If it isn’t social hazing, then what is going on here? Why has this issue gone on since May and servers are crashing every day?

    • RoundSparrow
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      110 months ago

      . However, I’m far from an expert,

      Funny, because I’m a published author and expert on messaging systems… like Lemmy. Iv’e been building them since 1986 professionally.

      There was a massive thread I posted dozens of comments on that came before today’s pull request… I suggest you read that too.

      Did you notice them even acknowledge server crashes are happening? Do you think developers ever suggest Memcache or Redis? Or discuss how Reddit solved their scaling in 2010 with PostgreSQL?

      but perhaps they themselves felt attacked. I know that wasn’t your intention, but misunderstanding happen, especially over text.

      I don’t have any trouble understanding a bad SQL statement that has 14 JOINs and being told “JOIN is a distraction” after posting tons of examples.

      Do we really need to spoon fed the stuff I did post?

      Have you never seen social hazing in action? is it possible that I might be on to something going on psychologically besides my autism?

      I can’t believe anyone thinks a server should be crashing with 1 user on it.

      • Anony Moose
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        410 months ago

        Have you never seen social hazing in action? is it possible that I might be on to something going on psychologically besides my autism?

        Okay, I can’t speak to whether social hazing happened or not, but I can tell you that you’re making me extremely uncomfortable.

        I started a dialogue, but at this point you’re now sending multiple messages for each of my replies, and asking a lot from me in terms of attention. I do not wish to continue this conversation, but I wish you all the best.

        • @[email protected]OP
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          310 months ago

          Welcome to discussions with RoundSparow!

          It can be a bit tiring interaction wise, but you usually can learn a lot

          • Anony Moose
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            310 months ago

            Haha, indeed. Any time I see an open-source discussion (especially a heated one), I’m reminded about just how much effort it takes to contribute. I’m happy to just stick to browsing memes :P

        • RoundSparrow
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          10 months ago

          who would have predicted that Elon Musk would do all the wild things he did with Twitter. Reddit pissing everyone off in June… pretty odd how audiences are behaving in 2023 towards all this. Oh yha, Threads, that coming on the scene too. 2023 has really been odd for audiences.

          The SQL speaks for itself, but I don’t know what’s going on in terms of why people are treating social media platforms like Lemmy, Twitter, Threads, Reddit this year so unusually. This SQL statement kind of thing has been covered in so many books, conferences, etc. It’s like forgotten history now in the era of Elon Musk X and Reddit Apollo times.

          I don’t know what to say other than I can try to hire a translator or teacher to explain how this SQL problem is obvious and well understood 13 years ago. I mean, there was a whole “NoSQL movement” because of this kind of thing. But I clearly can’t get people to hear past all the Elon Musk, Threads, Lemmy from Reddit … and I’m left describing it as ‘social hazing’ or whatever is gong on with social media.

          Lemmy has like 5 different Rust programming communities, but nobody fixing Lemmy. It’s surreal in 2023 the Elon Musk X days. I think it’s making all of us uncomfortable. The social movement underway.