Monitor only final states

There is no reason to monitor transition states so we ignore
ready and active states. We can get ratio of completed vs failed
requests from final states.

2 files changed, 25 insertions, 3 deletions

diff --git a/lib/gitlab/cluster/rack_timeout_observer.rb b/lib/gitlab/cluster/rack_timeout_observer.rb
index 2bc006b8011..5182b2be148 100644
--- a/lib/gitlab/cluster/rack_timeout_observer.rb
+++ b/lib/gitlab/cluster/rack_timeout_observer.rb
@@ -3,8 +3,10 @@
 module Gitlab
   module Cluster
     class RackTimeoutObserver
+      TRANSITION_STATES = %i(ready active).freeze
+
       def initialize
-        @counter = Gitlab::Metrics.counter(:rack_state_total, 'Number of requests in a given rack state')
+        @counter = Gitlab::Metrics.counter(:rack_requests_total, 'Number of requests in a given rack state')
       end
 
       # returns the Proc to be used as the observer callback block
@@ -17,6 +19,7 @@ module Gitlab
       def log_timeout_exception(env)
         info = env[::Rack::Timeout::ENV_INFO_KEY]
         return unless info
+        return if TRANSITION_STATES.include?(info.state)
 
         @counter.increment(labels(info, env))
       end
diff --git a/spec/lib/gitlab/cluster/rack_timeout_observer_spec.rb b/spec/lib/gitlab/cluster/rack_timeout_observer_spec.rb
index 2adb1d7cc71..68e5435450c 100644
--- a/spec/lib/gitlab/cluster/rack_timeout_observer_spec.rb
+++ b/spec/lib/gitlab/cluster/rack_timeout_observer_spec.rb
@@ -25,7 +25,7 @@ describe Gitlab::Cluster::RackTimeoutObserver do
 
       subject { described_class.new }
 
-      it 'increments timeout counter' do
+      it 'increments counter' do
         expect(counter)
           .to receive(:increment)
           .with({ controller: 'foo', action: 'bar', route: nil, state: :timed_out })
@@ -45,7 +45,7 @@ describe Gitlab::Cluster::RackTimeoutObserver do
 
       subject { described_class.new }
 
-      it 'increments timeout counter' do
+      it 'increments counter' do
         allow(endpoint).to receive_message_chain('route.pattern.origin') { 'foobar' }
         expect(counter)
           .to receive(:increment)
@@ -54,5 +54,24 @@ describe Gitlab::Cluster::RackTimeoutObserver do
         subject.callback.call(env)
       end
     end
+
+    context 'when request is being processed' do
+      let(:endpoint) { double }
+      let(:env) do
+        {
+          ::Rack::Timeout::ENV_INFO_KEY => double(state: :active),
+          Grape::Env::API_ENDPOINT => endpoint
+        }
+      end
+
+      subject { described_class.new }
+
+      it 'does not increment counter' do
+        allow(endpoint).to receive_message_chain('route.pattern.origin') { 'foobar' }
+        expect(counter).not_to receive(:increment)
+
+        subject.callback.call(env)
+      end
+    end
   end
 end