Restrict ProjectCacheWorker jobs to one per 15 min

This ensures ProjectCacheWorker jobs for a given project are performed
at most once per 15 minutes. This should reduce disk load a bit in cases
where there are multiple pushes happening (which should schedule
multiple ProjectCacheWorker jobs).

1 files changed, 27 insertions, 0 deletions

diff --git a/app/workers/project_cache_worker.rb b/app/workers/project_cache_worker.rb
index ccefd0f71a0..0d524e88dc3 100644
--- a/app/workers/project_cache_worker.rb
+++ b/app/workers/project_cache_worker.rb
@@ -1,9 +1,30 @@
+# Worker for updating any project specific caches.
+#
+# This worker runs at most once every 15 minutes per project. This is to ensure
+# that multiple instances of jobs for this worker don't hammer the underlying
+# storage engine as much.
 class ProjectCacheWorker
   include Sidekiq::Worker
 
   sidekiq_options queue: :default
 
+  LEASE_TIMEOUT = 15.minutes.to_i
+
   def perform(project_id)
+    if try_obtain_lease_for(project_id)
+      Rails.logger.
+        info("Obtained ProjectCacheWorker lease for project #{project_id}")
+    else
+      Rails.logger.
+        info("Could not obtain ProjectCacheWorker lease for project #{project_id}")
+
+      return
+    end
+
+    update_caches(project_id)
+  end
+
+  def update_caches(project_id)
     project = Project.find(project_id)
 
     return unless project.repository.exists?
@@ -15,4 +36,10 @@ class ProjectCacheWorker
       project.repository.build_cache
     end
   end
+
+  def try_obtain_lease_for(project_id)
+    Gitlab::ExclusiveLease.
+      new("project_cache_worker:#{project_id}", timeout: LEASE_TIMEOUT).
+      try_obtain
+  end
 end