Limited amount of pruned Event rows per run

CHANGELOG

@@ -3,6 +3,7 @@ Please view this file on the master branch, on stable branches it's out of date.
 v 8.12.0 (unreleased)
   - Add ability to fork to a specific namespace using API. (ritave)
   - Cleanup misalignments in Issue list view !6206
+  - Prune events older than 12 months. @ritave <olaf@tomalka.me>
   - Prepend blank line to `Closes` message on merge request linked to issue (lukehowell)
   - Prune events older than 12 months.
   - Filter tags by name !6121

app/workers/prune_old_events_worker.rb

@@ -3,6 +3,6 @@ class PruneOldEventsWorker
 
   def perform
     # Contribution calendar shows maximum 12 months of events
-    Event.where('created_at < ?', (12.months + 1.day).ago).destroy_all
+    Event.delete(Event.unscoped.where('created_at < ?', (12.months + 1.day).ago).limit(10_000).pluck(:id))
   end
 end

config/initializers/1_settings.rb

@@ -300,7 +300,7 @@ Settings.cron_jobs['remove_expired_group_links_worker'] ||= Settingslogic.new({}
 Settings.cron_jobs['remove_expired_group_links_worker']['cron'] ||= '10 0 * * *'
 Settings.cron_jobs['remove_expired_group_links_worker']['job_class'] = 'RemoveExpiredGroupLinksWorker'
 Settings.cron_jobs['prune_old_events_worker'] ||= Settingslogic.new({})
-Settings.cron_jobs['prune_old_events_worker']['cron'] ||= '0 0 * * *'
+Settings.cron_jobs['prune_old_events_worker']['cron'] ||= '* */6 * * *'
 Settings.cron_jobs['prune_old_events_worker']['job_class'] = 'PruneOldEventsWorker'
 
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