Deprecate and replace MR with approval rules metric

This:
- Sets counts.merged_merge_requests_using_approval_rules
as broken according with the metric lifecycle guidelines.
- Adds a new metric
counts.merged_merge_requests_using_approval_rules_distinct, which uses
distinct_count using metric instrumentation classes.
- Moves the original metric to `ee`, since it only applies to EE.

Changelog: fixed
EE: true

config/metrics/counts_all/20210216175206_merged_merge_requests_using_approval_rules.yml → ee/config/metrics/counts_all/20210216175206_merged_merge_requests_using_approval_rules.yml

@@ -7,14 +7,13 @@ product_stage: manage
 product_group: group::compliance
 product_category: compliance_management
 value_type: number
-status: active
+status: broken
+repair_issue_url: https://gitlab.com/gitlab-data/analytics/-/issues/11466
 time_frame: all
 data_source: database
 distribution:
-- ce
 - ee
 tier:
-- free
 - premium
 - ultimate
 performance_indicator_type: []

ee/config/metrics/counts_all/20220119165410_merged_merge_requests_using_approval_rules_distinct.yml

+---
+key_path: counts.merged_merge_requests_using_approval_rules_distinct
+name: count_distinct_merge_requests_using_approval_rules
+description: Count of distinct merge requests merged using approval rules
+product_section: dev
+product_stage: manage
+product_group: group::compliance
+product_category: compliance_management
+value_type: number
+status: active
+milestone: "14.8"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/78664
+time_frame: all
+data_source: database
+data_category: optional
+instrumentation_class: CountDistinctMergedMergeRequestsUsingApprovalRulesMetric
+performance_indicator_type: []
+distribution:
+- ee
+tier:
+- premium
+- ultimate

ee/lib/ee/gitlab/usage_data.rb

@@ -211,6 +211,7 @@ module EE
                 merged_merge_requests_using_approval_rules: count(::MergeRequest.merged.joins(:approval_rules), # rubocop: disable CodeReuse/ActiveRecord
                                                                   start: minimum_id(::MergeRequest),
                                                                   finish: maximum_id(::MergeRequest)),
+                merged_merge_requests_using_approval_rules_distinct: add_metric('CountDistinctMergedMergeRequestsUsingApprovalRulesMetric', time_frame: 'all'),
                 projects_mirrored_with_pipelines_enabled: count(::Project.mirrored_with_enabled_pipelines),
                 projects_reporting_ci_cd_back_to_github: count(::Integrations::Github.active),
                 status_page_projects: count(::StatusPage::ProjectSetting.enabled),

ee/lib/gitlab/usage/metrics/instrumentations/count_distinct_merged_merge_requests_using_approval_rules_metric.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Usage
+    module Metrics
+      module Instrumentations
+        class CountDistinctMergedMergeRequestsUsingApprovalRulesMetric < DatabaseMetric
+          operation :distinct_count
+
+          start { MergeRequest.minimum(:id) }
+          finish { MergeRequest.maximum(:id) }
+
+          relation { MergeRequest.merged.joins(:approval_rules) } # rubocop: disable CodeReuse/ActiveRecord
+
+          cache_start_and_finish_as :merge_request
+        end
+      end
+    end
+  end
+end

ee/spec/lib/gitlab/usage/metrics/instrumentations/count_distinct_merged_merge_requests_using_approval_rules_metric_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Usage::Metrics::Instrumentations::CountDistinctMergedMergeRequestsUsingApprovalRulesMetric do
+  let_it_be(:merge_request) { create(:merge_request, :merged) }
+  let_it_be(:approval_rule_1) { create(:approval_merge_request_rule, merge_request: merge_request) }
+  let_it_be(:approval_rule_2) { create(:approval_merge_request_rule, merge_request: merge_request) }
+
+  let_it_be(:other_merge_request) { create(:merge_request) }
+  let_it_be(:approval_rule_3) { create(:approval_merge_request_rule, merge_request: other_merge_request) }
+  let_it_be(:other_merged_merge_request) { create(:merge_request, :merged) }
+
+  let(:expected_value) { 1 }
+  let(:expected_query) { 'SELECT COUNT(DISTINCT "merge_requests"."id") FROM "merge_requests" INNER JOIN "approval_merge_request_rules" ON "approval_merge_request_rules"."merge_request_id" = "merge_requests"."id" WHERE ("merge_requests"."state_id" IN (3))' }
+
+  it_behaves_like 'a correct instrumented metric value and query', { time_frame: 'all' }
+end