Merge branch '21698-redis-runner-last-build' into 'master'

Reduce DB-load for build-queues by storing last_update in Redis

See merge request !8084

2 files changed, 10 insertions, 1 deletions

diff --git a/lib/api/helpers.rb b/lib/api/helpers.rb
index 6b81fbf294e..49c5f0652ab 100644
--- a/lib/api/helpers.rb
+++ b/lib/api/helpers.rb
@@ -226,7 +226,7 @@ module API
     end
 
     def render_api_error!(message, status)
-      error!({ 'message' => message }, status)
+      error!({ 'message' => message }, status, header)
     end
 
     def handle_api_exception(exception)
diff --git a/lib/ci/api/builds.rb b/lib/ci/api/builds.rb
index 142bce82286..c4bdef781f7 100644
--- a/lib/ci/api/builds.rb
+++ b/lib/ci/api/builds.rb
@@ -16,6 +16,13 @@ module Ci
           not_found! unless current_runner.active?
           update_runner_info
 
+          if current_runner.is_runner_queue_value_latest?(params[:last_update])
+            header 'X-GitLab-Last-Update', params[:last_update]
+            return build_not_found!
+          end
+
+          new_update = current_runner.ensure_runner_queue_value
+
           build = Ci::RegisterBuildService.new.execute(current_runner)
 
           if build
@@ -26,6 +33,8 @@ module Ci
           else
             Gitlab::Metrics.add_event(:build_not_found)
 
+            header 'X-GitLab-Last-Update', new_update
+
             build_not_found!
           end
         end