Track blocking epics removed on usage data

Record blocking epic removed on usage ping
and use RedisHLL for data aggregation.

Changelog: added
EE: true

ee/app/services/concerns/epics/related_epic_links/usage_data_helper.rb

 # frozen_string_literal: true
 
+# Helper to simplify recording related epics unique events on services.
+# Used by RelatedEpicLinks::CreateService and RelatedEpicLinks::DestroyService
+#
+# Calls the following methods on Gitlab::UsageDataCounters::EpicActivityUniqueCounter:
+#
+# track_linked_epic_with_type_relates_to_added
+# track_linked_epic_with_type_relates_to_removed
+# track_linked_epic_with_type_blocks_added
+# track_linked_epic_with_type_blocks_removed
+# track_linked_epic_with_type_is_blocked_by_added
+# track_linked_epic_with_type_is_blocked_by_removed
 module Epics::RelatedEpicLinks::UsageDataHelper
   ALLOWED_LINK_TYPES =
     [

ee/config/metrics/counts_28d/20210318183733_epics_usage_total_unique_counts_monthly.yml

@@ -47,6 +47,7 @@ options:
     - g_project_management_epic_related_added
     - g_project_management_epic_related_removed
     - g_project_management_epic_blocking_added
+    - g_project_management_epic_blocking_removed
 distribution:
 - ee
 tier:

ee/config/metrics/counts_28d/20220406164857_g_project_management_epic_blocking_removed_monthly.yml

+---
+key_path: redis_hll_counters.epics_usage.g_project_management_epic_blocking_removed_monthly
+description: Count of MAU removing blocking epics
+product_section: dev
+product_stage: plan
+product_group: group::product planning
+product_category: epics_usage
+value_type: number
+status: active
+milestone: "14.10"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/84408
+time_frame: 28d
+data_source: redis_hll
+data_category: optional
+instrumentation_class: RedisHLLMetric
+options:
+  events:
+    - g_project_management_epic_blocking_removed
+distribution:
+- ee
+tier:
+- ultimate

ee/config/metrics/counts_7d/20210318183220_epics_usage_total_unique_counts_weekly.yml

@@ -47,6 +47,7 @@ options:
     - g_project_management_epic_related_added
     - g_project_management_epic_related_removed
     - g_project_management_epic_blocking_added
+    - g_project_management_epic_blocking_removed
 distribution:
 - ee
 tier:

ee/config/metrics/counts_7d/20220406165118_g_project_management_epic_blocking_removed_weekly.yml

+---
+key_path: redis_hll_counters.epics_usage.g_project_management_epic_blocking_removed_weekly
+description: Count of WAU removing blocking epics
+product_section: dev
+product_stage: plan
+product_group: group::product planning
+product_category: epics_usage
+value_type: number
+status: active
+milestone: "14.10"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/84408
+time_frame: 7d
+data_source: redis_hll
+data_category: optional
+instrumentation_class: RedisHLLMetric
+options:
+  events:
+    - g_project_management_epic_blocking_removed
+distribution:
+- ee
+tier:
+- ultimate

ee/lib/gitlab/usage_data_counters/epic_activity_unique_counter.rb

@@ -38,6 +38,7 @@ module Gitlab
       EPIC_RELATED_ADDED = 'g_project_management_epic_related_added'
       EPIC_RELATED_REMOVED = 'g_project_management_epic_related_removed'
       EPIC_BLOCKING_ADDED = 'g_project_management_epic_blocking_added'
+      EPIC_BLOCKING_REMOVED = 'g_project_management_epic_blocking_removed'
 
       class << self
         def track_epic_created_action(author:)
@@ -165,6 +166,7 @@ module Gitlab
         end
 
         def track_linked_epic_with_type_blocks_removed(author:)
+          track_unique_action(EPIC_BLOCKING_REMOVED, author)
         end
 
         def track_linked_epic_with_type_is_blocked_by_added(author:)

ee/spec/lib/gitlab/usage_data_counters/epic_activity_unique_counter_spec.rb

@@ -373,4 +373,16 @@ RSpec.describe Gitlab::UsageDataCounters::EpicActivityUniqueCounter, :clean_gitl
 
     it_behaves_like 'does not track when feature flag is disabled', :track_epics_activity
   end
+
+  context 'for blocking epic removed' do
+    def track_action(params)
+      described_class.track_linked_epic_with_type_blocks_removed(**params)
+    end
+
+    it_behaves_like 'a daily tracked issuable event' do
+      let(:action) { described_class::EPIC_BLOCKING_REMOVED }
+    end
+
+    it_behaves_like 'does not track when feature flag is disabled', :track_epics_activity
+  end
 end

ee/spec/services/epics/related_epic_links/destroy_service_spec.rb

@@ -17,19 +17,35 @@ RSpec.describe Epics::RelatedEpicLinks::DestroyService do
     it_behaves_like 'a destroyable issuable link'
 
     context 'event tracking' do
+      let(:issuable_link) { create(:related_epic_link, link_type: link_type ) }
+
       before do
         issuable_link.source.resource_parent.add_reporter(user)
         issuable_link.target.resource_parent.add_reporter(user)
       end
 
-      context 'for relates_to link type' do
-        it 'records event for related epic link destroyed' do
+      shared_examples 'a recorded event' do
+        it 'records event for destroyed link' do
           expect(Gitlab::UsageDataCounters::EpicActivityUniqueCounter)
-            .to receive(:track_linked_epic_with_type_relates_to_removed).with(author: user).once
+            .to receive(tracking_method).with(author: user).once
 
           subject
         end
       end
+
+      context 'for relates_to link type' do
+        let(:link_type) { IssuableLink::TYPE_RELATES_TO }
+        let(:tracking_method) { :track_linked_epic_with_type_relates_to_removed }
+
+        it_behaves_like 'a recorded event'
+      end
+
+      context 'for blocks link type' do
+        let(:link_type) { IssuableLink::TYPE_BLOCKS }
+        let(:tracking_method) { :track_linked_epic_with_type_blocks_removed }
+
+        it_behaves_like 'a recorded event'
+      end
     end
   end
 end

lib/gitlab/usage_data_counters/known_events/epic_events.yml

@@ -206,3 +206,9 @@
   redis_slot: project_management
   aggregation: daily
   feature_flag: track_epics_activity
+
+- name: g_project_management_epic_blocking_removed
+  category: epics_usage
+  redis_slot: project_management
+  aggregation: daily
+  feature_flag: track_epics_activity