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
That has nothing to do with the issue I’m talking about. Every server with the amount of data in them would fail. Doesn’t matter if you had 100 servers on standby.
The Rust logic for database access and PostgreSQL logic in lemmy is unoptimized and there is a serious lack of Diesel programming skills. site_aggregates table had a mistake where 1500 rows were updated for every single new comment and post - and it only got noticed when lemmy.ca was crashing so hard they made a complete copy of the data and studied what was gong on.
Throwing hardware at it, as you describe, has been the other thing… massive numbers of CPU cores. What’s needed is to learn what Reddit did before 2010 with PostgreSQL… as Reddit also used PostgreSQL (and is open source).
Downtime because you avoid using Redis or Memcached caching at all costs in your project isn’t common to see in major corporations. But Lemmy avoids caching any data from PostgreSQL at all costs. Been that way for several years. May 17, 2010: “Lesson 5: Memcache;”
As I said in my very first comment, server crashing as a way to scale is a very interesting approach.
EDIT: Freudian slip, “memecached” instead of Memcached
deleted by creator
That’s a much more… coherent explanation than your original one, friend. I wouldn’t have argued this point if you had started here.
If anyone bothered to actually look at the SQL SELECT that Lemmy uses to list posts every time you hit refresh it would be blindingly obvious how convoluted it is. yet the community does not talk about the programming issues and instead keeps raising money for 64 core hardware upgrades without recognizing just how tiny Lemmy’s database really is and how 57K users is not a large number at all!
I mentioned “ORM” right in my first comment.
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 ((((((( ((("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 ;