Implement simple in memory cache that expires after 5 minutes

1 files changed, 19 insertions, 7 deletions

diff --git a/lib/gitlab/metrics/method_call.rb b/lib/gitlab/metrics/method_call.rb
index ab7e7a06a77..744c489d46e 100644
--- a/lib/gitlab/metrics/method_call.rb
+++ b/lib/gitlab/metrics/method_call.rb
@@ -18,6 +18,24 @@ module Gitlab
         end
       end
 
+      def self.call_measurement_enabled?
+        return @call_measurement_enabled unless call_measurement_enabled_cache_expired?
+        MUTEX.synchronize do
+          return @call_measurement_enabled unless call_measurement_enabled_cache_expired?
+          @call_measurement_enabled_cache_expires_at = Time.now + 5.minutes
+          @call_measurement_enabled = Feature.get(:prometheus_metrics_method_instrumentation).enabled?
+        end
+      end
+
+      def self.call_measurement_enabled_cache_expired?
+        @call_measurement_enabled.nil? || @call_measurement_enabled_cache_expires_at.nil? || @call_measurement_enabled_cache_expires_at < Time.now
+      end
+
+      def self.call_measurement_enabled_cache_expire
+        @call_measurement_enabled = nil
+        @call_measurement_enabled_cache_expires_at = nil
+      end
+
       # name - The full name of the method (including namespace) such as
       #        `User#sign_in`.
       #
@@ -45,7 +63,7 @@ module Gitlab
         @cpu_time += cpu_time
         @call_count += 1
 
-        if call_measurement_enabled? && above_threshold?
+        if self.class.call_measurement_enabled? && above_threshold?
           self.class.call_duration_histogram.observe(@transaction.labels.merge(labels), real_time / 1000.0)
         end
 
@@ -70,12 +88,6 @@ module Gitlab
       def above_threshold?
         real_time >= Metrics.method_call_threshold
       end
-
-      def call_measurement_enabled?
-        Rails.cache.fetch(:prometheus_metrics_method_instrumentation_enabled, expires_in: 5.minutes) do
-          Feature.get(:prometheus_metrics_method_instrumentation).enabled?
-        end
-      end
     end
   end
 end