Change i_code_review_create_mr metric to total counts

Now that we support total counts with 7d and 28d time frames, we can
stop using a distinct counter to implement the
redis_hll_counters.code_review.i_code_review_create_mr_*
metrics and instead count the number of i_code_review_user_create_mr
events triggered.

Changelog: changed

config/metrics/counts_28d/20221213182900_i_code_review_create_mr_monthly.yml

 ---
+# This metric used to be implemented as a RedisHLL counter. Therefor, the redis_hll_counters prefix.
 key_path: redis_hll_counters.code_review.i_code_review_create_mr_monthly
 description: Count of unique merge requests created per month
 product_section: dev
@@ -9,14 +10,15 @@ status: active
 milestone: "15.7"
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/106869
 time_frame: 28d
-data_source: redis_hll
+data_source: internal_events
 data_category: operational
-instrumentation_class: RedisHLLMetric
 performance_indicator_type:
 - customer_health_score
 options:
   events:
-  - i_code_review_create_mr
+  - i_code_review_user_create_mr
+events:
+  - name: i_code_review_user_create_mr
 distribution:
 - ce
 - ee

config/metrics/counts_7d/20221213183300_i_code_review_create_mr_weekly.yml

@@ -9,13 +9,14 @@ status: active
 milestone: "15.7"
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/106869
 time_frame: 7d
-data_source: redis_hll
+data_source: internal_events
 data_category: operational
-instrumentation_class: RedisHLLMetric
 performance_indicator_type: []
 options:
   events:
-  - i_code_review_create_mr
+  - i_code_review_user_create_mr
+events:
+  - name: i_code_review_user_create_mr
 distribution:
 - ce
 - ee

db/post_migrate/20231204095802_change_i_code_review_create_mr_keys_from_redis_hll_to_redis.rb

+# frozen_string_literal: true
+
+class ChangeICodeReviewCreateMrKeysFromRedisHllToRedis < Gitlab::Database::Migration[2.2]
+  milestone '16.8'
+
+  disable_ddl_transaction!
+  restrict_gitlab_migration gitlab_schema: :gitlab_main
+
+  REDIS_HLL_PREFIX = '{hll_counters}_i_code_review_create_mr'
+  REDIS_PREFIX = '{event_counters}_i_code_review_user_create_mr'
+
+  def up
+    # For each old (redis_hll) counter we find the corresponding target (redis) counter and add
+    # old value to migrate a metric. If the Redis counter does not exist, it will get created.
+    # Since the RedisHLL keys expire after 6 weeks, we will migrate 6 keys at the most.
+    Gitlab::Redis::SharedState.with do |redis|
+      redis.scan_each(match: "#{REDIS_HLL_PREFIX}-*") do |key|
+        redis_key = key.sub(REDIS_HLL_PREFIX, REDIS_PREFIX)
+        redis_hll_value = redis.pfcount(key)
+
+        redis.incrby(redis_key, redis_hll_value)
+      end
+    end
+  end
+
+  def down
+    # no-op
+  end
+end

db/schema_migrations/20231204095802

+c2fc8e11eb2ac22bd4f37dcabd9468ddfce6285a9b796560c8ce9a21fa0047e1
\ No newline at end of file

lib/gitlab/usage_data_counters/merge_request_activity_unique_counter.rb

@@ -6,7 +6,6 @@ module MergeRequestActivityUniqueCounter
       MR_DIFFS_ACTION = 'i_code_review_mr_diffs'
       MR_DIFFS_SINGLE_FILE_ACTION = 'i_code_review_mr_single_file_diffs'
       MR_DIFFS_USER_SINGLE_FILE_ACTION = 'i_code_review_user_single_file_diffs'
-      MR_CREATE_ACTION = 'i_code_review_create_mr'
       MR_USER_CREATE_ACTION = 'i_code_review_user_create_mr'
       MR_CLOSE_ACTION = 'i_code_review_user_close_mr'
       MR_REOPEN_ACTION = 'i_code_review_user_reopen_mr'
@@ -64,15 +63,10 @@ def track_mr_diffs_single_file_action(merge_request:, user:)
         end
 
         def track_create_mr_action(user:, merge_request:)
-          track_unique_action_by_merge_request(MR_CREATE_ACTION, merge_request)
-
-          project = merge_request.target_project
-
           Gitlab::InternalEvents.track_event(
             MR_USER_CREATE_ACTION,
             user: user,
-            project: project,
-            namespace: project.namespace
+            project: merge_request.target_project
           )
         end
 

spec/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter_spec.rb

@@ -55,14 +55,6 @@
     let(:merge_request) { create(:merge_request) }
     let(:target_project) { merge_request.target_project }
 
-    it_behaves_like 'a tracked merge request unique event' do
-      let(:action) { described_class::MR_USER_CREATE_ACTION }
-    end
-
-    it_behaves_like 'a tracked merge request unique event' do
-      let(:action) { described_class::MR_CREATE_ACTION }
-    end
-
     it_behaves_like 'internal event tracking' do
       let(:event) { described_class::MR_USER_CREATE_ACTION }
       let(:project) { target_project }

spec/migrations/20231204095802_change_i_code_review_create_mr_keys_from_redis_hll_to_redis_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+require_migration!
+
+RSpec.describe ChangeICodeReviewCreateMrKeysFromRedisHllToRedis, :migration, :clean_gitlab_redis_cache, feature_category: :service_ping do
+  def set_redis_hll(key, value)
+    Gitlab::Redis::HLL.add(key: key, value: value, expiry: 6.weeks)
+  end
+
+  def get_int_from_redis(key)
+    Gitlab::Redis::SharedState.with { |redis| redis.get(key)&.to_i }
+  end
+
+  describe "#up" do
+    before do
+      set_redis_hll('{hll_counters}_i_code_review_create_mr-2023-16', value: 1)
+      set_redis_hll('{hll_counters}_i_code_review_create_mr-2023-16', value: 2)
+      set_redis_hll('{hll_counters}_i_code_review_create_mr-2023-47', value: 3)
+      set_redis_hll('{hll_counters}_i_code_review_create_mr-2023-48', value: 1)
+      set_redis_hll('{hll_counters}_i_code_review_create_mr-2023-49', value: 2)
+      set_redis_hll('{hll_counters}_i_code_review_create_mr-2023-49', value: 4)
+      set_redis_hll('{hll_counters}_some_other_event-2023-49', value: 7)
+    end
+
+    it 'migrates all RedisHLL keys for i_code_review_create_mr', :aggregate_failures do
+      migrate!
+
+      expect(get_int_from_redis('{event_counters}_i_code_review_user_create_mr-2023-16')).to eq(2)
+      expect(get_int_from_redis('{event_counters}_i_code_review_user_create_mr-2023-47')).to eq(1)
+      expect(get_int_from_redis('{event_counters}_i_code_review_user_create_mr-2023-48')).to eq(1)
+      expect(get_int_from_redis('{event_counters}_i_code_review_user_create_mr-2023-49')).to eq(2)
+    end
+
+    it 'does not not migrate other RedisHLL keys' do
+      migrate!
+
+      expect(get_int_from_redis('{event_counters}_some_other_event-2023-16')).to be_nil
+    end
+  end
+end