Improve resiliency of build pickingimprove-ci-redis-queueing

Every time we pick a new build, or we get into conflict we force runner to retry the operation to make sure that all builds are being picked.

It makes us to loose one request, but also makes sure that we are consistent.

It is fair trade, as number of generated builds is relatively small 0.1% compared to the traffic.

1 files changed, 19 insertions, 10 deletions

diff --git a/lib/ci/api/builds.rb b/lib/ci/api/builds.rb
index 746e76a1b1f..f39b509873c 100644
--- a/lib/ci/api/builds.rb
+++ b/lib/ci/api/builds.rb
@@ -13,35 +13,44 @@ module Ci
         post "register" do
           authenticate_runner!
           required_attributes! [:token]
-          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]
-            Gitlab::Metrics.add_event(:build_not_found_cached)
+            Gitlab::Metrics.add_event(:build_not_found_cached,
+              version: get_runner_version)
+            header_last_update(params[:last_update])
             return build_not_found!
           end
 
           new_update = current_runner.ensure_runner_queue_value
 
+          unless current_runner.active?
+            Gitlab::Metrics.add_event(:runner_inactive,
+              version: get_runner_version)
+            header_last_update(new_update)
+            return build_not_found!
+          end
+
           result = Ci::RegisterJobService.new(current_runner).execute
 
           if result.valid?
             if result.build
               Gitlab::Metrics.add_event(:build_found,
-                                        project: result.build.project.path_with_namespace)
-
+                project: result.build.project.path_with_namespace,
+                version: get_runner_version)
+              header_last_update(current_runner.tick_runner_queue_value)
               present result.build, with: Entities::BuildDetails
             else
-              Gitlab::Metrics.add_event(:build_not_found)
-
-              header 'X-GitLab-Last-Update', new_update
-
+              Gitlab::Metrics.add_event(:build_not_found,
+                version: get_runner_version)
+              header_last_update(new_update)
               build_not_found!
             end
           else
             # We received build that is invalid due to concurrency conflict
-            Gitlab::Metrics.add_event(:build_invalid)
+            Gitlab::Metrics.add_event(:build_invalid,
+              version: get_runner_version)
+            header_last_update(current_runner.tick_runner_queue_value)
             conflict!
           end
         end