1 files changed, 58 insertions, 0 deletions
diff --git a/lib/gitlab/background_migration/populate_projects_star_count.rb b/lib/gitlab/background_migration/populate_projects_star_count.rb
new file mode 100644
index 00000000000..085d576637e
--- /dev/null
+++ b/lib/gitlab/background_migration/populate_projects_star_count.rb
@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    # The class to populates the star counter of projects
+    class PopulateProjectsStarCount < BatchedMigrationJob
+      MAX_UPDATE_RETRIES = 3
+
+      operation_name :update_all
+
+      def perform
+        each_sub_batch do |sub_batch|
+          update_with_retry(sub_batch)
+        end
+      end
+
+      private
+
+      # rubocop:disable Database/RescueQueryCanceled
+      # rubocop:disable Database/RescueStatementTimeout
+      def update_with_retry(sub_batch)
+        update_attempt = 1
+
+        begin
+          update_batch(sub_batch)
+        rescue ActiveRecord::StatementTimeout, ActiveRecord::QueryCanceled => e
+          update_attempt += 1
+
+          if update_attempt <= MAX_UPDATE_RETRIES
+            sleep(5)
+            retry
+          end
+
+          raise e
+        end
+      end
+      # rubocop:enable Database/RescueQueryCanceled
+      # rubocop:enable Database/RescueStatementTimeout
+
+      def update_batch(sub_batch)
+        ApplicationRecord.connection.execute <<~SQL
+          WITH batched_relation AS #{Gitlab::Database::AsWithMaterialized.materialized_if_supported} (#{sub_batch.select(:id).to_sql})
+          UPDATE projects
+          SET star_count = (
+            SELECT COUNT(*)
+            FROM users_star_projects
+            INNER JOIN users
+            ON users_star_projects.user_id = users.id
+            WHERE users_star_projects.project_id = batched_relation.id
+            AND users.state = 'active'
+          )
+          FROM batched_relation
+          WHERE projects.id = batched_relation.id
+        SQL
+      end
+    end
+  end
+end