1 files changed, 22 insertions, 7 deletions

diff --git a/lib/gitlab/metrics/method_call.rb b/lib/gitlab/metrics/method_call.rb
index 65d55576ac2..c2f9db56824 100644
--- a/lib/gitlab/metrics/method_call.rb
+++ b/lib/gitlab/metrics/method_call.rb
@@ -1,7 +1,11 @@
+# rubocop:disable Style/ClassVars
+
 module Gitlab
   module Metrics
     # Class for tracking timing information about method calls
     class MethodCall
+      @@measurement_enabled_cache = Concurrent::AtomicBoolean.new(false)
+      @@measurement_enabled_cache_expires_at = Concurrent::AtomicReference.new(Time.now.to_i)
       MUTEX = Mutex.new
       BASE_LABELS = { module: nil, method: nil }.freeze
       attr_reader :real_time, :cpu_time, :call_count, :labels
@@ -18,6 +22,10 @@ module Gitlab
         end
       end
 
+      def self.measurement_enabled_cache_expires_at
+        @@measurement_enabled_cache_expires_at
+      end
+
       # name - The full name of the method (including namespace) such as
       #        `User#sign_in`.
       #
@@ -27,8 +35,8 @@ module Gitlab
         @transaction = transaction
         @name = name
         @labels = { module: @module_name, method: @method_name }
-        @real_time = 0
-        @cpu_time = 0
+        @real_time = 0.0
+        @cpu_time = 0.0
         @call_count = 0
       end
 
@@ -46,7 +54,7 @@ module Gitlab
         @call_count += 1
 
         if call_measurement_enabled? && above_threshold?
-          self.class.call_duration_histogram.observe(@transaction.labels.merge(labels), real_time / 1000.0)
+          self.class.call_duration_histogram.observe(@transaction.labels.merge(labels), real_time)
         end
 
         retval
@@ -57,8 +65,8 @@ module Gitlab
         Metric.new(
           Instrumentation.series,
           {
-            duration: real_time,
-            cpu_duration: cpu_time,
+            duration: real_time.in_milliseconds.to_i,
+            cpu_duration: cpu_time.in_milliseconds.to_i,
             call_count: call_count
           },
           method: @name
@@ -68,11 +76,18 @@ module Gitlab
       # Returns true if the total runtime of this method exceeds the method call
       # threshold.
       def above_threshold?
-        real_time >= Metrics.method_call_threshold
+        real_time.in_milliseconds >= Metrics.method_call_threshold
       end
 
       def call_measurement_enabled?
-        Feature.get(:prometheus_metrics_method_instrumentation).enabled?
+        expires_at = @@measurement_enabled_cache_expires_at.value
+        if expires_at < Time.now.to_i
+          if @@measurement_enabled_cache_expires_at.compare_and_set(expires_at, 1.minute.from_now.to_i)
+            @@measurement_enabled_cache.value = Feature.get(:prometheus_metrics_method_instrumentation).enabled?
+          end
+        end
+
+        @@measurement_enabled_cache.value
       end
     end
   end