use chrono::{DateTime, TimeZone, Utc}; use clokwerk::{AsyncScheduler, TimeUnits as CTimeUnits}; use diesel::{ dsl::IntervalDsl, sql_query, sql_types::{Integer, Timestamptz}, ExpressionMethods, NullableExpressionMethods, QueryDsl, QueryableByName, }; use diesel_async::{AsyncPgConnection, RunQueryDsl}; use lemmy_api_common::context::LemmyContext; use lemmy_db_schema::{ schema::{ captcha_answer, comment, community_person_ban, instance, person, post, received_activity, sent_activity, }, source::instance::{Instance, InstanceForm}, utils::{get_conn, naive_now, now, DbPool, DELETED_REPLACEMENT_TEXT}, }; use lemmy_routes::nodeinfo::NodeInfo; use lemmy_utils::error::{LemmyError, LemmyResult}; use reqwest_middleware::ClientWithMiddleware; use std::time::Duration; use tracing::{error, info, warn}; /// Schedules various cleanup tasks for lemmy in a background thread pub async fn setup(context: LemmyContext) -> Result<(), LemmyError> { // Setup the connections let mut scheduler = AsyncScheduler::new(); startup_jobs(&mut context.pool()).await; let context_1 = context.clone(); // Update active counts every hour scheduler.every(CTimeUnits::hour(1)).run(move || { let context = context_1.clone(); async move { active_counts(&mut context.pool()).await; update_banned_when_expired(&mut context.pool()).await; } }); let context_1 = context.clone(); // Update hot ranks every 15 minutes scheduler.every(CTimeUnits::minutes(10)).run(move || { let context = context_1.clone(); async move { update_hot_ranks(&mut context.pool()).await; } }); let context_1 = context.clone(); // Delete any captcha answers older than ten minutes, every ten minutes scheduler.every(CTimeUnits::minutes(10)).run(move || { let context = context_1.clone(); async move { delete_expired_captcha_answers(&mut context.pool()).await; } }); let context_1 = context.clone(); // Clear old activities every week scheduler.every(CTimeUnits::weeks(1)).run(move || { let context = context_1.clone(); async move { clear_old_activities(&mut context.pool()).await; } }); let context_1 = context.clone(); // Remove old rate limit buckets after 1 to 2 hours of inactivity scheduler.every(CTimeUnits::hour(1)).run(move || { let context = context_1.clone(); async move { let hour = Duration::from_secs(3600); context.settings_updated_channel().remove_older_than(hour); } }); let context_1 = context.clone(); // Overwrite deleted & removed posts and comments every day scheduler.every(CTimeUnits::days(1)).run(move || { let context = context_1.clone(); async move { overwrite_deleted_posts_and_comments(&mut context.pool()).await; } }); let context_1 = context.clone(); // Update the Instance Software scheduler.every(CTimeUnits::days(1)).run(move || { let context = context_1.clone(); async move { update_instance_software(&mut context.pool(), context.client()) .await .map_err(|e| warn!("Failed to update instance software: {e}")) .ok(); } }); // Manually run the scheduler in an event loop loop { scheduler.run_pending().await; tokio::time::sleep(Duration::from_millis(1000)).await; } } /// Run these on server startup async fn startup_jobs(pool: &mut DbPool<'_>) { active_counts(pool).await; update_hot_ranks(pool).await; update_banned_when_expired(pool).await; clear_old_activities(pool).await; overwrite_deleted_posts_and_comments(pool).await; } /// Update the hot_rank columns for the aggregates tables /// Runs in batches until all necessary rows are updated once async fn update_hot_ranks(pool: &mut DbPool<'_>) { info!("Updating hot ranks for all history..."); let conn = get_conn(pool).await; match conn { Ok(mut conn) => { process_post_aggregates_ranks_in_batches(&mut conn).await; process_ranks_in_batches( &mut conn, "comment_aggregates", "a.hot_rank != 0", "SET hot_rank = hot_rank(a.score, a.published)", ) .await; process_ranks_in_batches( &mut conn, "community_aggregates", "a.hot_rank != 0", "SET hot_rank = hot_rank(a.subscribers, a.published)", ) .await; info!("Finished hot ranks update!"); } Err(e) => { error!("Failed to get connection from pool: {e}"); } } } #[derive(QueryableByName)] struct HotRanksUpdateResult { #[diesel(sql_type = Timestamptz)] published: DateTime, } /// Runs the hot rank update query in batches until all rows have been processed. /// In `where_clause` and `set_clause`, "a" will refer to the current aggregates table. /// Locked rows are skipped in order to prevent deadlocks (they will likely get updated on the next /// run) async fn process_ranks_in_batches( conn: &mut AsyncPgConnection, table_name: &str, where_clause: &str, set_clause: &str, ) { let process_start_time: DateTime = Utc .timestamp_opt(0, 0) .single() .expect("0 timestamp creation"); let update_batch_size = 1000; // Bigger batches than this tend to cause seq scans let mut processed_rows_count = 0; let mut previous_batch_result = Some(process_start_time); while let Some(previous_batch_last_published) = previous_batch_result { // Raw `sql_query` is used as a performance optimization - Diesel does not support doing this // in a single query (neither as a CTE, nor using a subquery) let result = sql_query(format!( r#"WITH batch AS (SELECT a.id FROM {aggregates_table} a WHERE a.published > $1 AND ({where_clause}) ORDER BY a.published LIMIT $2 FOR UPDATE SKIP LOCKED) UPDATE {aggregates_table} a {set_clause} FROM batch WHERE a.id = batch.id RETURNING a.published; "#, aggregates_table = table_name, set_clause = set_clause, where_clause = where_clause )) .bind::(previous_batch_last_published) .bind::(update_batch_size) .get_results::(conn) .await; match result { Ok(updated_rows) => { processed_rows_count += updated_rows.len(); previous_batch_result = updated_rows.last().map(|row| row.published); } Err(e) => { error!("Failed to update {} hot_ranks: {}", table_name, e); break; } } } info!( "Finished process_hot_ranks_in_batches execution for {} (processed {} rows)", table_name, processed_rows_count ); } /// Post aggregates is a special case, since it needs to join to the community_aggregates /// table, to get the active monthly user counts. async fn process_post_aggregates_ranks_in_batches(conn: &mut AsyncPgConnection) { let process_start_time: DateTime = Utc .timestamp_opt(0, 0) .single() .expect("0 timestamp creation"); let update_batch_size = 1000; // Bigger batches than this tend to cause seq scans let mut processed_rows_count = 0; let mut previous_batch_result = Some(process_start_time); while let Some(previous_batch_last_published) = previous_batch_result { let result = sql_query( r#"WITH batch AS (SELECT pa.id FROM post_aggregates pa WHERE pa.published > $1 AND (pa.hot_rank != 0 OR pa.hot_rank_active != 0) ORDER BY pa.published LIMIT $2 FOR UPDATE SKIP LOCKED) UPDATE post_aggregates pa SET hot_rank = hot_rank(pa.score, pa.published), hot_rank_active = hot_rank(pa.score, pa.newest_comment_time_necro), scaled_rank = scaled_rank(pa.score, pa.published, ca.users_active_month) FROM batch, community_aggregates ca WHERE pa.id = batch.id and pa.community_id = ca.community_id RETURNING pa.published; "#, ) .bind::(previous_batch_last_published) .bind::(update_batch_size) .get_results::(conn) .await; match result { Ok(updated_rows) => { processed_rows_count += updated_rows.len(); previous_batch_result = updated_rows.last().map(|row| row.published); } Err(e) => { error!("Failed to update {} hot_ranks: {}", "post_aggregates", e); break; } } } info!( "Finished process_hot_ranks_in_batches execution for {} (processed {} rows)", "post_aggregates", processed_rows_count ); } async fn delete_expired_captcha_answers(pool: &mut DbPool<'_>) { let conn = get_conn(pool).await; match conn { Ok(mut conn) => { diesel::delete( captcha_answer::table .filter(captcha_answer::published.lt(now() - IntervalDsl::minutes(10))), ) .execute(&mut conn) .await .map(|_| { info!("Done."); }) .map_err(|e| error!("Failed to clear old captcha answers: {e}")) .ok(); } Err(e) => { error!("Failed to get connection from pool: {e}"); } } } /// Clear old activities (this table gets very large) async fn clear_old_activities(pool: &mut DbPool<'_>) { info!("Clearing old activities..."); let conn = get_conn(pool).await; match conn { Ok(mut conn) => { diesel::delete(sent_activity::table.filter(sent_activity::published.lt(now() - 3.months()))) .execute(&mut conn) .await .map_err(|e| error!("Failed to clear old sent activities: {e}")) .ok(); diesel::delete( received_activity::table.filter(received_activity::published.lt(now() - 3.months())), ) .execute(&mut conn) .await .map(|_| info!("Done.")) .map_err(|e| error!("Failed to clear old received activities: {e}")) .ok(); } Err(e) => { error!("Failed to get connection from pool: {e}"); } } } /// overwrite posts and comments 30d after deletion async fn overwrite_deleted_posts_and_comments(pool: &mut DbPool<'_>) { info!("Overwriting deleted posts..."); let conn = get_conn(pool).await; match conn { Ok(mut conn) => { diesel::update( post::table .filter(post::deleted.eq(true)) .filter(post::updated.lt(now().nullable() - 1.months())) .filter(post::body.ne(DELETED_REPLACEMENT_TEXT)), ) .set(( post::body.eq(DELETED_REPLACEMENT_TEXT), post::name.eq(DELETED_REPLACEMENT_TEXT), )) .execute(&mut conn) .await .map(|_| { info!("Done."); }) .map_err(|e| error!("Failed to overwrite deleted posts: {e}")) .ok(); info!("Overwriting deleted comments..."); diesel::update( comment::table .filter(comment::deleted.eq(true)) .filter(comment::updated.lt(now().nullable() - 1.months())) .filter(comment::content.ne(DELETED_REPLACEMENT_TEXT)), ) .set(comment::content.eq(DELETED_REPLACEMENT_TEXT)) .execute(&mut conn) .await .map(|_| { info!("Done."); }) .map_err(|e| error!("Failed to overwrite deleted comments: {e}")) .ok(); } Err(e) => { error!("Failed to get connection from pool: {e}"); } } } /// Re-calculate the site and community active counts every 12 hours async fn active_counts(pool: &mut DbPool<'_>) { info!("Updating active site and community aggregates ..."); let conn = get_conn(pool).await; match conn { Ok(mut conn) => { let intervals = vec![ ("1 day", "day"), ("1 week", "week"), ("1 month", "month"), ("6 months", "half_year"), ]; for i in &intervals { let update_site_stmt = format!( "update site_aggregates set users_active_{} = (select * from site_aggregates_activity('{}')) where site_id = 1", i.1, i.0 ); sql_query(update_site_stmt) .execute(&mut conn) .await .map_err(|e| error!("Failed to update site stats: {e}")) .ok(); let update_community_stmt = format!("update community_aggregates ca set users_active_{} = mv.count_ from community_aggregates_activity('{}') mv where ca.community_id = mv.community_id_", i.1, i.0); sql_query(update_community_stmt) .execute(&mut conn) .await .map_err(|e| error!("Failed to update community stats: {e}")) .ok(); } info!("Done."); } Err(e) => { error!("Failed to get connection from pool: {e}"); } } } /// Set banned to false after ban expires async fn update_banned_when_expired(pool: &mut DbPool<'_>) { info!("Updating banned column if it expires ..."); let conn = get_conn(pool).await; match conn { Ok(mut conn) => { diesel::update( person::table .filter(person::banned.eq(true)) .filter(person::ban_expires.lt(now().nullable())), ) .set(person::banned.eq(false)) .execute(&mut conn) .await .map_err(|e| error!("Failed to update person.banned when expires: {e}")) .ok(); diesel::delete( community_person_ban::table.filter(community_person_ban::expires.lt(now().nullable())), ) .execute(&mut conn) .await .map_err(|e| error!("Failed to remove community_ban expired rows: {e}")) .ok(); } Err(e) => { error!("Failed to get connection from pool: {e}"); } } } /// Updates the instance software and version /// /// TODO: if instance has been dead for a long time, it should be checked less frequently async fn update_instance_software( pool: &mut DbPool<'_>, client: &ClientWithMiddleware, ) -> LemmyResult<()> { info!("Updating instances software and versions..."); let conn = get_conn(pool).await; match conn { Ok(mut conn) => { let instances = instance::table.get_results::(&mut conn).await?; for instance in instances { let node_info_url = format!("https://{}/nodeinfo/2.0.json", instance.domain); // The `updated` column is used to check if instances are alive. If it is more than three days // in the past, no outgoing activities will be sent to that instance. However not every // Fediverse instance has a valid Nodeinfo endpoint (its not required for Activitypub). That's // why we always need to mark instances as updated if they are alive. let default_form = InstanceForm::builder() .domain(instance.domain.clone()) .updated(Some(naive_now())) .build(); let form = match client.get(&node_info_url).send().await { Ok(res) if res.status().is_client_error() => { // Instance doesnt have nodeinfo but sent a response, consider it alive Some(default_form) } Ok(res) => match res.json::().await { Ok(node_info) => { // Instance sent valid nodeinfo, write it to db let software = node_info.software.as_ref(); Some( InstanceForm::builder() .domain(instance.domain) .updated(Some(naive_now())) .software(software.and_then(|s| s.name.clone())) .version(software.and_then(|s| s.version.clone())) .build(), ) } Err(_) => { // No valid nodeinfo but valid HTTP response, consider instance alive Some(default_form) } }, Err(_) => { // dead instance, do nothing None } }; if let Some(form) = form { diesel::update(instance::table.find(instance.id)) .set(form) .execute(&mut conn) .await?; } } info!("Finished updating instances software and versions..."); } Err(e) => { error!("Failed to get connection from pool: {e}"); } } Ok(()) } #[cfg(test)] mod tests { #![allow(clippy::unwrap_used)] #![allow(clippy::indexing_slicing)] use lemmy_routes::nodeinfo::NodeInfo; use reqwest::Client; #[tokio::test] #[ignore] async fn test_nodeinfo() { let client = Client::builder().build().unwrap(); let lemmy_ml_nodeinfo = client .get("https://lemmy.ml/nodeinfo/2.0.json") .send() .await .unwrap() .json::() .await .unwrap(); assert_eq!(lemmy_ml_nodeinfo.software.unwrap().name.unwrap(), "lemmy"); } }