src/scheduled_tasks.rs

   1 // Scheduler, and trait for .seconds(), .minutes(), etc.
   2 use clokwerk::{Scheduler, TimeUnits};
   3 // Import week days and WeekDay
   4 use diesel::{sql_query, PgConnection, RunQueryDsl};
   5 use lemmy_db_schema::{source::activity::Activity, DbPool};
   6 use log::info;
   7 use std::{thread, time::Duration};
   8
   9 /// Schedules various cleanup tasks for lemmy in a background thread
  10 pub fn setup(pool: DbPool) {
  11   let mut scheduler = Scheduler::new();
  12
  13   let conn = pool.get().unwrap();
  14   active_counts(&conn);
  15
  16   // On startup, reindex the tables non-concurrently
  17   // TODO remove this for now, since it slows down startup a lot on lemmy.ml
  18   reindex_aggregates_tables(&conn, true);
  19   scheduler.every(1.hour()).run(move || {
  20     active_counts(&conn);
  21     reindex_aggregates_tables(&conn, true);
  22   });
  23
  24   let conn = pool.get().unwrap();
  25   clear_old_activities(&conn);
  26   scheduler.every(1.weeks()).run(move || {
  27     clear_old_activities(&conn);
  28   });
  29
  30   // Manually run the scheduler in an event loop
  31   loop {
  32     scheduler.run_pending();
  33     thread::sleep(Duration::from_millis(1000));
  34   }
  35 }
  36
  37 /// Reindex the aggregates tables every one hour
  38 /// This is necessary because hot_rank is actually a mutable function:
  39 /// https://dba.stackexchange.com/questions/284052/how-to-create-an-index-based-on-a-time-based-function-in-postgres?noredirect=1#comment555727_284052
  40 fn reindex_aggregates_tables(conn: &PgConnection, concurrently: bool) {
  41   for table_name in &[
  42     "post_aggregates",
  43     "comment_aggregates",
  44     "community_aggregates",
  45   ] {
  46     reindex_table(conn, table_name, concurrently);
  47   }
  48 }
  49
  50 fn reindex_table(conn: &PgConnection, table_name: &str, concurrently: bool) {
  51   let concurrently_str = if concurrently { "concurrently" } else { "" };
  52   info!("Reindexing table {} {} ...", concurrently_str, table_name);
  53   let query = format!("reindex table {} {}", concurrently_str, table_name);
  54   sql_query(query).execute(conn).expect("reindex table");
  55   info!("Done.");
  56 }
  57
  58 /// Clear old activities (this table gets very large)
  59 fn clear_old_activities(conn: &PgConnection) {
  60   info!("Clearing old activities...");
  61   Activity::delete_olds(conn).expect("clear old activities");
  62   info!("Done.");
  63 }
  64
  65 /// Re-calculate the site and community active counts every 12 hours
  66 fn active_counts(conn: &PgConnection) {
  67   info!("Updating active site and community aggregates ...");
  68
  69   let intervals = vec![
  70     ("1 day", "day"),
  71     ("1 week", "week"),
  72     ("1 month", "month"),
  73     ("6 months", "half_year"),
  74   ];
  75
  76   for i in &intervals {
  77     let update_site_stmt = format!(
  78       "update site_aggregates set users_active_{} = (select * from site_aggregates_activity('{}'))",
  79       i.1, i.0
  80     );
  81     sql_query(update_site_stmt)
  82       .execute(conn)
  83       .expect("update site stats");
  84
  85     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);
  86     sql_query(update_community_stmt)
  87       .execute(conn)
  88       .expect("update community stats");
  89   }
  90
  91   info!("Done.");
  92 }