Fix MultipleDatabases offenses

This change fixes some of the MultipleDatabases offenses.

.rubocop_manual_todo.yml

@@ -2879,45 +2879,9 @@ Style/RegexpLiteralMixedPreserve:
     - 'spec/support/helpers/require_migration.rb'
     - 'spec/views/layouts/_head.html.haml_spec.rb'
 
+# WIP see: https://gitlab.com/gitlab-org/gitlab/-/issues/335808
 Database/MultipleDatabases:
   Exclude:
-    - 'app/mailers/previews/notify_preview.rb'
-    - 'app/models/application_setting.rb'
-    - 'app/models/internal_id.rb'
-    - 'app/services/auto_merge/base_service.rb'
-    - 'app/services/ci/delete_unit_tests_service.rb'
-    - 'app/services/ci/unlock_artifacts_service.rb'
-    - 'app/services/deployments/update_environment_service.rb'
-    - 'app/services/design_management/copy_design_collection/copy_service.rb'
-    - 'app/services/feature_flags/create_service.rb'
-    - 'app/services/feature_flags/destroy_service.rb'
-    - 'app/services/feature_flags/update_service.rb'
-    - 'app/services/issuable/clone/base_service.rb'
-    - 'app/services/issuable/common_system_notes_service.rb'
-    - 'app/services/issuable/destroy_label_links_service.rb'
-    - 'app/services/packages/create_dependency_service.rb'
-    - 'app/services/packages/go/create_package_service.rb'
-    - 'app/services/packages/npm/create_package_service.rb'
-    - 'app/services/packages/terraform_module/create_package_service.rb'
-    - 'app/services/projects/cleanup_service.rb'
-    - 'app/services/projects/fetch_statistics_increment_service.rb'
-    - 'app/services/releases/update_service.rb'
-    - 'app/services/todos/destroy/destroyed_issuable_service.rb'
-    - 'ee/app/models/dora/daily_metrics.rb'
-    - 'ee/app/services/analytics/devops_adoption/enabled_namespaces/bulk_delete_service.rb'
-    - 'ee/app/services/approval_rules/finalize_service.rb'
-    - 'ee/app/services/approval_rules/project_rule_destroy_service.rb'
-    - 'ee/app/services/app_sec/dast/site_profiles/create_service.rb'
-    - 'ee/app/services/app_sec/dast/site_profiles/update_service.rb'
-    - 'ee/app/services/ci/minutes/update_build_minutes_service.rb'
-    - 'ee/app/services/ee/issuable/common_system_notes_service.rb'
-    - 'ee/app/services/group_saml/group_managed_accounts/transfer_membership_service.rb'
-    - 'ee/app/services/group_saml/sign_up_service.rb'
-    - 'ee/app/services/iterations/roll_over_issues_service.rb'
-    - 'ee/app/services/security/store_scan_service.rb'
-    - 'ee/app/services/timebox_report_service.rb'
-    - 'ee/app/services/vulnerability_feedback/create_service.rb'
-    - 'ee/lib/ee/gitlab/checks/push_rule_check.rb'
     - 'ee/lib/ee/gitlab/database.rb'
     - 'ee/lib/gitlab/geo/database_tasks.rb'
     - 'ee/lib/gitlab/geo/geo_tasks.rb'
@@ -2933,14 +2897,7 @@ Database/MultipleDatabases:
     - 'lib/after_commit_queue.rb'
     - 'lib/api/rubygem_packages.rb'
     - 'lib/backup/manager.rb'
-    - 'lib/gitlab/analytics/cycle_analytics/stage_query_helpers.rb'
-    - 'lib/gitlab/chaos.rb'
     - 'lib/gitlab/current_settings.rb'
-    - 'lib/gitlab/database/batch_count.rb'
-    - 'lib/gitlab/database/batch_counter.rb'
-    - 'lib/gitlab/database/count/reltuples_count_strategy.rb'
-    - 'lib/gitlab/database/count/tablesample_count_strategy.rb'
-    - 'lib/gitlab/database/grant.rb'
     - 'lib/gitlab/database/load_balancing/load_balancer.rb'
     - 'lib/gitlab/database/load_balancing.rb'
     - 'lib/gitlab/database/load_balancing/sticking.rb'
@@ -2962,7 +2919,6 @@ Database/MultipleDatabases:
     - 'lib/gitlab/database/schema_cache_with_renamed_table.rb'
     - 'lib/gitlab/database/schema_migrations/context.rb'
     - 'lib/gitlab/database/schema_version_files.rb'
-    - 'lib/gitlab/database/similarity_score.rb'
     - 'lib/gitlab/database/unidirectional_copy_trigger.rb'
     - 'lib/gitlab/database/with_lock_retries.rb'
     - 'lib/gitlab/gitlab_import/importer.rb'
@@ -2971,13 +2927,8 @@ Database/MultipleDatabases:
     - 'lib/gitlab/import_export/relation_tree_restorer.rb'
     - 'lib/gitlab/legacy_github_import/importer.rb'
     - 'lib/gitlab/metrics/samplers/database_sampler.rb'
-    - 'lib/gitlab/optimistic_locking.rb'
-    - 'lib/gitlab/otp_key_rotator.rb'
-    - 'lib/gitlab/profiler.rb'
     - 'lib/gitlab/seeder.rb'
     - 'lib/gitlab/sherlock/query.rb'
-    - 'lib/gitlab/sql/glob.rb'
-    - 'lib/gitlab/sql/set_operator.rb'
     - 'lib/system_check/orphans/repository_check.rb'
     - 'spec/db/schema_spec.rb'
     - 'spec/features/admin/dashboard_spec.rb'
@@ -2993,9 +2944,6 @@ Database/MultipleDatabases:
     - 'spec/lib/gitlab/profiler_spec.rb'
     - 'spec/lib/gitlab/query_limiting/active_support_subscriber_spec.rb'
     - 'spec/lib/gitlab/sidekiq_logging/structured_logger_spec.rb'
-    - 'spec/lib/gitlab/sql/cte_spec.rb'
-    - 'spec/lib/gitlab/sql/glob_spec.rb'
-    - 'spec/lib/gitlab/sql/recursive_cte_spec.rb'
     - 'spec/lib/gitlab/usage_data_metrics_spec.rb'
     - 'spec/lib/gitlab/usage_data_queries_spec.rb'
     - 'spec/lib/gitlab/usage/metrics/names_suggestions/relation_parsers/constraints_spec.rb'
@@ -3003,11 +2951,6 @@ Database/MultipleDatabases:
     - 'spec/lib/gitlab/usage/metrics/instrumentations/database_metric_spec.rb'
     - 'spec/lib/gitlab/utils/usage_data_spec.rb'
     - 'spec/models/application_setting_spec.rb'
-    - 'spec/models/concerns/case_sensitivity_spec.rb'
-    - 'spec/models/concerns/sortable_spec.rb'
-    - 'spec/models/concerns/where_composite_spec.rb'
-    - 'spec/models/experiment_spec.rb'
-    - 'spec/models/internal_id_spec.rb'
     - 'spec/models/project_feature_usage_spec.rb'
     - 'spec/models/users_statistics_spec.rb'
     - 'spec/requests/api/statistics_spec.rb'

app/mailers/previews/notify_preview.rb

@@ -246,7 +246,7 @@ class NotifyPreview < ActionMailer::Preview
   def cleanup
     email = nil
 
-    ActiveRecord::Base.transaction do
+    ActiveRecord::Base.transaction do # rubocop: disable Database/MultipleDatabases
       email = yield
       raise ActiveRecord::Rollback
     end

app/models/application_setting.rb

@@ -627,7 +627,7 @@ class ApplicationSetting < ApplicationRecord
   # prevent this from happening, we do a sanity check that the
   # primary key constraint is present before inserting a new entry.
   def self.check_schema!
-    return if ActiveRecord::Base.connection.primary_key(self.table_name).present?
+    return if connection.primary_key(self.table_name).present?
 
     raise "The `#{self.table_name}` table is missing a primary key constraint in the database schema"
   end

app/models/internal_id.rb

@@ -83,7 +83,7 @@ class InternalId < ApplicationRecord
       self.internal_id_transactions_total.increment(
         operation: operation,
         usage: usage.to_s,
-        in_transaction: ActiveRecord::Base.connection.transaction_open?.to_s
+        in_transaction: ActiveRecord::Base.connection.transaction_open?.to_s # rubocop: disable Database/MultipleDatabases
       )
     end
 
@@ -317,7 +317,7 @@ class InternalId < ApplicationRecord
       stmt.set(arel_table[:last_value] => new_value)
       stmt.wheres = InternalId.filter_by(scope, usage).arel.constraints
 
-      ActiveRecord::Base.connection.insert(stmt, 'Update InternalId', 'last_value')
+      ActiveRecord::Base.connection.insert(stmt, 'Update InternalId', 'last_value') # rubocop: disable Database/MultipleDatabases
     end
 
     def create_record!(subject, scope, usage, init)

app/services/auto_merge/base_service.rb

@@ -6,7 +6,7 @@ module AutoMerge
     include MergeRequests::AssignsMergeParams
 
     def execute(merge_request)
-      ActiveRecord::Base.transaction do
+      ActiveRecord::Base.transaction do # rubocop: disable Database/MultipleDatabases
         register_auto_merge_parameters!(merge_request)
         yield if block_given?
       end
@@ -29,7 +29,7 @@ module AutoMerge
     end
 
     def cancel(merge_request)
-      ActiveRecord::Base.transaction do
+      ActiveRecord::Base.transaction do # rubocop: disable Database/MultipleDatabases
         clear_auto_merge_parameters!(merge_request)
         yield if block_given?
       end
@@ -41,7 +41,7 @@ module AutoMerge
     end
 
     def abort(merge_request, reason)
-      ActiveRecord::Base.transaction do
+      ActiveRecord::Base.transaction do # rubocop: disable Database/MultipleDatabases
         clear_auto_merge_parameters!(merge_request)
         yield if block_given?
       end

app/services/ci/delete_unit_tests_service.rb

@@ -23,7 +23,7 @@ module Ci
     def delete_batch!(klass)
       deleted = 0
 
-      ActiveRecord::Base.transaction do
+      klass.transaction do
         ids = klass.deletable.lock('FOR UPDATE SKIP LOCKED').limit(BATCH_SIZE).pluck(:id)
         break if ids.empty?
 

app/services/ci/unlock_artifacts_service.rb

@@ -17,7 +17,7 @@ module Ci
       SQL
 
       loop do
-        break if ActiveRecord::Base.connection.exec_query(query).empty?
+        break if Ci::Pipeline.connection.exec_query(query).empty?
       end
     end
 

app/services/deployments/update_environment_service.rb

@@ -26,7 +26,7 @@ module Deployments
     end
 
     def update_environment(deployment)
-      ActiveRecord::Base.transaction do
+      ActiveRecord::Base.transaction do # rubocop: disable Database/MultipleDatabases
         # Renew attributes at update
         renew_external_url
         renew_auto_stop_in

app/services/design_management/copy_design_collection/copy_service.rb

@@ -36,7 +36,7 @@ module DesignManagement
         with_temporary_branch do
           copy_commits!
 
-          ActiveRecord::Base.transaction do
+          ApplicationRecord.transaction do
             design_ids = copy_designs!
             version_ids = copy_versions!
             copy_actions!(design_ids, version_ids)

app/services/feature_flags/create_service.rb

@@ -6,7 +6,7 @@ module FeatureFlags
       return error('Access Denied', 403) unless can_create?
       return error('Version is invalid', :bad_request) unless valid_version?
 
-      ActiveRecord::Base.transaction do
+      ApplicationRecord.transaction do
         feature_flag = project.operations_feature_flags.new(params)
 
         if feature_flag.save

app/services/feature_flags/destroy_service.rb

@@ -11,7 +11,7 @@ module FeatureFlags
     def destroy_feature_flag(feature_flag)
       return error('Access Denied', 403) unless can_destroy?(feature_flag)
 
-      ActiveRecord::Base.transaction do
+      ApplicationRecord.transaction do
         if feature_flag.destroy
           save_audit_event(audit_event(feature_flag))
 

app/services/feature_flags/update_service.rb

@@ -12,7 +12,7 @@ module FeatureFlags
       return error('Access Denied', 403) unless can_update?(feature_flag)
       return error('Not Found', 404) unless valid_user_list_ids?(feature_flag, user_list_ids(params))
 
-      ActiveRecord::Base.transaction do
+      ApplicationRecord.transaction do
         feature_flag.assign_attributes(params)
 
         feature_flag.strategies.each do |strategy|

app/services/issuable/clone/base_service.rb

@@ -14,7 +14,7 @@ module Issuable
         # Using transaction because of a high resources footprint
         # on rewriting notes (unfolding references)
         #
-        ActiveRecord::Base.transaction do
+        ApplicationRecord.transaction do
           @new_entity = create_new_entity
 
           update_new_entity

app/services/issuable/common_system_notes_service.rb

@@ -9,7 +9,7 @@ module Issuable
 
       # We disable touch so that created system notes do not update
       # the noteable's updated_at field
-      ActiveRecord::Base.no_touching do
+      ApplicationRecord.no_touching do
         if is_update
           if issuable.previous_changes.include?('title')
             create_title_change_note(issuable.previous_changes['title'].first)

app/services/issuable/destroy_label_links_service.rb

@@ -22,7 +22,7 @@ module Issuable
       SQL
 
       loop do
-        result = ActiveRecord::Base.connection.execute(delete_query)
+        result = LabelLink.connection.execute(delete_query)
 
         break if result.cmd_tuples == 0
       end

app/services/packages/create_dependency_service.rb

@@ -27,7 +27,7 @@ module Packages
         dependencies_to_insert = names_and_version_patterns.reject { |k, _| k.in?(existing_names) }
       end
 
-      ActiveRecord::Base.transaction do
+      ApplicationRecord.transaction do
         inserted_ids = bulk_insert_package_dependencies(dependencies_to_insert)
         bulk_insert_package_dependency_links(type, (existing_ids + inserted_ids))
       end

app/services/packages/go/create_package_service.rb

@@ -23,7 +23,7 @@ module Packages
         files[:mod] = prepare_file(version, :mod, version.gomod)
         files[:zip] = prepare_file(version, :zip, version.archive.string)
 
-        ActiveRecord::Base.transaction do
+        ApplicationRecord.transaction do
           # create new package and files
           package = create_package
           files.each { |type, (file, digests)| create_file(package, type, file, digests) }

app/services/packages/npm/create_package_service.rb

@@ -9,7 +9,7 @@ module Packages
         return error('Package already exists.', 403) if current_package_exists?
         return error('File is too large.', 400) if file_size_exceeded?
 
-        ActiveRecord::Base.transaction { create_npm_package! }
+        ApplicationRecord.transaction { create_npm_package! }
       end
 
       private

app/services/packages/terraform_module/create_package_service.rb

@@ -11,7 +11,7 @@ module Packages
         return error('Package version already exists.', 403) if current_package_version_exists?
         return error('File is too large.', 400) if file_size_exceeded?
 
-        ActiveRecord::Base.transaction { create_terraform_module_package! }
+        ApplicationRecord.transaction { create_terraform_module_package! }
       end
 
       private

app/services/projects/cleanup_service.rb

@@ -65,7 +65,7 @@ module Projects
     def cleanup_diffs(response)
       old_commit_shas = extract_old_commit_shas(response.entries)
 
-      ActiveRecord::Base.transaction do
+      ApplicationRecord.transaction do
         cleanup_merge_request_diffs(old_commit_shas)
         cleanup_note_diff_files(old_commit_shas)
       end

app/services/projects/fetch_statistics_increment_service.rb

@@ -15,7 +15,7 @@ module Projects
         ON CONFLICT (project_id, date) DO UPDATE SET fetch_count = #{table_name}.fetch_count + 1
       SQL
 
-      ActiveRecord::Base.connection.execute(increment_fetch_count_sql)
+      ProjectDailyStatistic.connection.execute(increment_fetch_count_sql)
     end
 
     private

app/services/releases/update_service.rb

@@ -18,7 +18,7 @@ module Releases
       # when it does assign_attributes instead of actual saving
       # this leads to the validation error being raised
       # see https://gitlab.com/gitlab-org/gitlab/-/merge_requests/43385
-      ActiveRecord::Base.transaction do
+      ApplicationRecord.transaction do
         if release.update(params)
           execute_hooks(release, 'update')
           success(tag: existing_tag, release: release, milestones_updated: milestones_updated?(previous_milestones))

app/services/todos/destroy/destroyed_issuable_service.rb

@@ -20,7 +20,7 @@ module Todos
         SQL
 
         loop do
-          result = ActiveRecord::Base.connection.execute(delete_query)
+          result = Todo.connection.execute(delete_query)
 
           break if result.cmd_tuples == 0
 

ee/app/models/dora/daily_metrics.rb

@@ -43,7 +43,7 @@ module Dora
           )
           VALUES (
             #{environment.id},
-            #{ActiveRecord::Base.connection.quote(date.to_s)},
+            #{connection.quote(date.to_s)},
             (#{deployment_frequency}),
             (#{lead_time_for_changes})
           )

ee/app/services/analytics/devops_adoption/enabled_namespaces/bulk_delete_service.rb

@@ -14,7 +14,7 @@ module Analytics
 
           result = nil
 
-          ActiveRecord::Base.transaction do
+          ApplicationRecord.transaction do
             deletion_services.each do |service|
               response = service.execute
 

ee/app/services/app_sec/dast/site_profiles/create_service.rb

@@ -17,7 +17,7 @@ module AppSec
         def execute(name:, target_url:, **params)
           return ServiceResponse.error(message: _('Insufficient permissions')) unless allowed?
 
-          ActiveRecord::Base.transaction do
+          ApplicationRecord.transaction do
             @dast_site = ::DastSites::FindOrCreateService.new(project, current_user).execute!(url: target_url)
             params.merge!(project: project, dast_site: dast_site, name: name).compact!
 

ee/app/services/app_sec/dast/site_profiles/update_service.rb

@@ -21,7 +21,7 @@ module AppSec
 
           return ServiceResponse.error(message: _('Cannot modify %{profile_name} referenced in security policy') % { profile_name: dast_site_profile.name }) if referenced_in_security_policy?
 
-          ActiveRecord::Base.transaction do
+          ApplicationRecord.transaction do
             auditor = AppSec::Dast::SiteProfiles::Audit::UpdateService.new(project, current_user, {
               dast_site_profile: dast_site_profile,
               new_params: params.dup,

ee/app/services/approval_rules/finalize_service.rb

@@ -11,7 +11,7 @@ module ApprovalRules
     def execute
       return unless merge_request.merged?
 
-      ActiveRecord::Base.transaction do
+      ApplicationRecord.transaction do
         if merge_request.approval_rules.regular.exists?
           merge_group_members_into_users
         else

ee/app/services/approval_rules/project_rule_destroy_service.rb

@@ -9,7 +9,7 @@ module ApprovalRules
     end
 
     def execute
-      ActiveRecord::Base.transaction do
+      ApplicationRecord.transaction do
         # Removes only MR rules associated with project rule
         remove_associated_approval_rules_from_unmerged_merge_requests
 

ee/app/services/ee/issuable/common_system_notes_service.rb

@@ -10,7 +10,7 @@ module EE
       def execute(issuable, old_labels: [], old_milestone: nil, is_update: true)
         super
 
-        ActiveRecord::Base.no_touching do
+        ApplicationRecord.no_touching do
           handle_weight_change
           handle_iteration_change
 

ee/app/services/group_saml/group_managed_accounts/transfer_membership_service.rb

@@ -18,7 +18,7 @@ module GroupSaml
 
         return false unless current_user.verified_email?(saml_email)
 
-        ActiveRecord::Base.transaction do
+        ApplicationRecord.transaction do
           if destroy_non_gma_identities && leave_non_gma_memberships && transfer_user
             identity_linker = Gitlab::Auth::GroupSaml::IdentityLinker.new(current_user, oauth_data, session, group.saml_provider)
             identity_linker.link

ee/app/services/group_saml/sign_up_service.rb

@@ -11,7 +11,7 @@ module GroupSaml
     end
 
     def execute
-      ActiveRecord::Base.transaction do
+      ApplicationRecord.transaction do
         new_user.managing_group = group if group.saml_provider&.enforced_group_managed_accounts?
 
         if new_user.save

ee/app/services/iterations/roll_over_issues_service.rb

@@ -18,7 +18,7 @@ module Iterations
       from_iteration.issues.opened.each_batch(of: BATCH_SIZE) do |issues|
         add_iteration_events, remove_iteration_events = iteration_events(issues)
 
-        ActiveRecord::Base.transaction do
+        ApplicationRecord.transaction do
           issues.update_all(sprint_id: to_iteration.id, updated_at: rolled_over_at)
           Gitlab::Database.bulk_insert(ResourceIterationEvent.table_name, remove_iteration_events) # rubocop:disable Gitlab/BulkInsert
           Gitlab::Database.bulk_insert(ResourceIterationEvent.table_name, add_iteration_events) # rubocop:disable Gitlab/BulkInsert

ee/app/services/security/store_scan_service.rb

@@ -43,7 +43,7 @@ module Security
     end
 
     def update_deduplicated_findings
-      ActiveRecord::Base.transaction do
+      Security::Scan.transaction do
         security_scan.findings.update_all(deduplicated: false)
 
         security_scan.findings

ee/app/services/timebox_report_service.rb

@@ -168,7 +168,7 @@ class TimeboxReportService
     strong_memoize(:resource_events) do
       union = Gitlab::SQL::Union.new([resource_timebox_events, state_events, weight_events]) # rubocop: disable Gitlab/Union
 
-      ActiveRecord::Base.connection.execute("(#{union.to_sql}) ORDER BY created_at LIMIT #{EVENT_COUNT_LIMIT + 1}")
+      ApplicationRecord.connection.execute("(#{union.to_sql}) ORDER BY created_at LIMIT #{EVENT_COUNT_LIMIT + 1}")
     end
   end
   # rubocop: enable CodeReuse/ActiveRecord

ee/app/services/vulnerability_feedback/create_service.rb

@@ -58,7 +58,7 @@ module VulnerabilityFeedback
 
     def create_issue
       # Wrap Feedback and Issue creation in the same transaction
-      ActiveRecord::Base.transaction do
+      ApplicationRecord.transaction do
         issue = @params[:issue]
 
         # Create a new issue if one does not exist
@@ -126,7 +126,7 @@ module VulnerabilityFeedback
     end
 
     def dismiss_existing_vulnerability
-      ActiveRecord::Base.transaction do
+      ApplicationRecord.transaction do
         if dismiss_vulnerability? && existing_vulnerability
           Vulnerabilities::DismissService.new(current_user,
                                               existing_vulnerability,

ee/lib/ee/gitlab/checks/push_rule_check.rb

@@ -94,7 +94,7 @@ module EE
               yield
             end
           ensure # rubocop: disable Layout/RescueEnsureAlignment
-            ActiveRecord::Base.clear_active_connections!
+            ActiveRecord::Base.clear_active_connections! # rubocop: disable Database/MultipleDatabases
           end
         end
       end

lib/gitlab/analytics/cycle_analytics/stage_query_helpers.rb

@@ -5,7 +5,7 @@ module Gitlab
     module CycleAnalytics
       module StageQueryHelpers
         def execute_query(query)
-          ActiveRecord::Base.connection.execute(query.to_sql)
+          ApplicationRecord.connection.execute(query.to_sql)
         end
 
         def zero_interval

lib/gitlab/chaos.rb

@@ -31,7 +31,7 @@ module Gitlab
       expected_end_time = Time.now + duration_s
 
       while Time.now < expected_end_time
-        ActiveRecord::Base.connection.execute("SELECT 1")
+        ApplicationRecord.connection.execute("SELECT 1")
 
         end_interval_time = Time.now + [duration_s, interval_s].min
         rand while Time.now < end_interval_time

lib/gitlab/database/batch_counter.rb

@@ -31,7 +31,7 @@ module Gitlab
       end
 
       def count(batch_size: nil, mode: :itself, start: nil, finish: nil)
-        raise 'BatchCount can not be run inside a transaction' if ActiveRecord::Base.connection.transaction_open?
+        raise 'BatchCount can not be run inside a transaction' if @relation.connection.transaction_open?
 
         check_mode!(mode)
 

lib/gitlab/database/count/reltuples_count_strategy.rb

@@ -54,7 +54,7 @@ module Gitlab
 
           # Querying tuple stats only works on the primary. Due to load balancing, the
           # easiest way to do this is to start a transaction.
-          ActiveRecord::Base.transaction do
+          ActiveRecord::Base.transaction do # rubocop: disable Database/MultipleDatabases
             get_statistics(non_sti_table_names, check_statistics: check_statistics).each_with_object({}) do |row, data|
               model = table_to_model[row.table_name]
               data[model] = row.estimate

lib/gitlab/database/count/tablesample_count_strategy.rb

@@ -61,7 +61,7 @@ module Gitlab
             #{where_clause(model)}
           SQL
 
-          rows = ActiveRecord::Base.connection.select_all(query)
+          rows = ActiveRecord::Base.connection.select_all(query) # rubocop: disable Database/MultipleDatabases
 
           Integer(rows.first['count'])
         end

lib/gitlab/database/grant.rb

@@ -10,7 +10,7 @@ module Gitlab
         # We _must not_ use quote_table_name as this will produce double
         # quotes on PostgreSQL and for "has_table_privilege" we need single
         # quotes.
-        connection = ActiveRecord::Base.connection
+        connection = ActiveRecord::Base.connection # rubocop: disable Database/MultipleDatabases
         quoted_table = connection.quote(table)
 
         begin

lib/gitlab/database/postgres_hll/batch_distinct_counter.rb

@@ -57,7 +57,7 @@ module Gitlab
         # @param finish final pkey range
         # @return [Gitlab::Database::PostgresHll::Buckets] HyperLogLog data structure instance that can estimate number of unique elements
         def execute(batch_size: nil, start: nil, finish: nil)
-          raise 'BatchCount can not be run inside a transaction' if ActiveRecord::Base.connection.transaction_open?
+          raise 'BatchCount can not be run inside a transaction' if ActiveRecord::Base.connection.transaction_open? # rubocop: disable Database/MultipleDatabases
 
           batch_size ||= DEFAULT_BATCH_SIZE
           start = actual_start(start)

lib/gitlab/database/similarity_score.rb

@@ -67,7 +67,7 @@ module Gitlab
       def self.build_expression(search:, rules:)
         return EXPRESSION_ON_INVALID_INPUT if search.blank? || rules.empty?
 
-        quoted_search = ActiveRecord::Base.connection.quote(search.to_s)
+        quoted_search = ApplicationRecord.connection.quote(search.to_s)
 
         first_expression, *expressions = rules.map do |rule|
           rule_to_arel(quoted_search, rule)
@@ -110,7 +110,7 @@ module Gitlab
 
       # CAST(multiplier AS numeric)
       def self.multiplier_expression(rule)
-        quoted_multiplier = ActiveRecord::Base.connection.quote(rule.fetch(:multiplier, DEFAULT_MULTIPLIER).to_s)
+        quoted_multiplier = ApplicationRecord.connection.quote(rule.fetch(:multiplier, DEFAULT_MULTIPLIER).to_s)
 
         Arel::Nodes::NamedFunction.new('CAST', [Arel.sql(quoted_multiplier).as('numeric')])
       end

lib/gitlab/optimistic_locking.rb

@@ -11,7 +11,7 @@ module Gitlab
       retry_attempts = 0
 
       begin
-        ActiveRecord::Base.transaction do
+        ActiveRecord::Base.transaction do # rubocop: disable Database/MultipleDatabases
           yield(subject)
         end
       rescue ActiveRecord::StaleObjectError

lib/gitlab/otp_key_rotator.rb

@@ -36,7 +36,7 @@ module Gitlab
       raise ArgumentError, "New key is too short! Must be 256 bits" if new_key.size < 64
 
       write_csv do |csv|
-        ActiveRecord::Base.transaction do
+        User.transaction do
           User.with_two_factor.in_batches do |relation| # rubocop: disable Cop/InBatches
             rows = relation.pluck(:id, :encrypted_otp_secret, :encrypted_otp_secret_iv, :encrypted_otp_secret_salt)
             rows.each do |row|
@@ -54,7 +54,7 @@ module Gitlab
 
     # rubocop: disable CodeReuse/ActiveRecord
     def rollback!
-      ActiveRecord::Base.transaction do
+      User.transaction do
         CSV.foreach(filename, headers: HEADERS, return_headers: false) do |row|
           User.where(id: row['user_id']).update_all(encrypted_otp_secret: row['old_value'])
         end

lib/gitlab/profiler.rb

@@ -119,18 +119,18 @@ module Gitlab
 
     def self.with_custom_logger(logger)
       original_colorize_logging = ActiveSupport::LogSubscriber.colorize_logging
-      original_activerecord_logger = ActiveRecord::Base.logger
+      original_activerecord_logger = ApplicationRecord.logger
       original_actioncontroller_logger = ActionController::Base.logger
 
       if logger
         ActiveSupport::LogSubscriber.colorize_logging = false
-        ActiveRecord::Base.logger = logger
+        ApplicationRecord.logger = logger
         ActionController::Base.logger = logger
       end
 
       yield.tap do
         ActiveSupport::LogSubscriber.colorize_logging = original_colorize_logging
-        ActiveRecord::Base.logger = original_activerecord_logger
+        ApplicationRecord.logger = original_activerecord_logger
         ActionController::Base.logger = original_actioncontroller_logger
       end
     end

lib/gitlab/sql/glob.rb

@@ -17,7 +17,7 @@ module Gitlab
       end
 
       def q(string)
-        ActiveRecord::Base.connection.quote(string)
+        ApplicationRecord.connection.quote(string)
       end
     end
   end

lib/gitlab/sql/set_operator.rb

@@ -33,7 +33,7 @@ module Gitlab
         # aren't incremented properly when joining relations together this way.
         # By using "unprepared_statements" we remove the usage of placeholders
         # (thus fixing this problem), at a slight performance cost.
-        fragments = ActiveRecord::Base.connection.unprepared_statement do
+        fragments = ApplicationRecord.connection.unprepared_statement do
           relations.map do |rel|
             remove_order ? rel.reorder(nil).to_sql : rel.to_sql
           end.reject(&:blank?)

spec/lib/gitlab/sql/cte_spec.rb

@@ -8,9 +8,9 @@ RSpec.describe Gitlab::SQL::CTE do
       relation = User.where(id: 1)
       cte = described_class.new(:cte_name, relation)
       sql = cte.to_arel.to_sql
-      name = ActiveRecord::Base.connection.quote_table_name(:cte_name)
+      name = ApplicationRecord.connection.quote_table_name(:cte_name)
 
-      sql1 = ActiveRecord::Base.connection.unprepared_statement do
+      sql1 = ApplicationRecord.connection.unprepared_statement do
         relation.except(:order).to_sql
       end
 
@@ -30,8 +30,8 @@ RSpec.describe Gitlab::SQL::CTE do
       cte = described_class.new(:cte_name, nil)
       table = Arel::Table.new(:kittens)
 
-      source_name = ActiveRecord::Base.connection.quote_table_name(:cte_name)
-      alias_name = ActiveRecord::Base.connection.quote_table_name(:kittens)
+      source_name = ApplicationRecord.connection.quote_table_name(:cte_name)
+      alias_name = ApplicationRecord.connection.quote_table_name(:kittens)
 
       expect(cte.alias_to(table).to_sql).to eq("#{source_name} AS #{alias_name}")
     end

spec/lib/gitlab/sql/glob_spec.rb

@@ -46,10 +46,10 @@ RSpec.describe Gitlab::SQL::Glob do
   end
 
   def query(sql)
-    ActiveRecord::Base.connection.select_all(sql)
+    ApplicationRecord.connection.select_all(sql)
   end
 
   def quote(string)
-    ActiveRecord::Base.connection.quote(string)
+    ApplicationRecord.connection.quote(string)
   end
 end

spec/lib/gitlab/sql/recursive_cte_spec.rb

@@ -14,9 +14,9 @@ RSpec.describe Gitlab::SQL::RecursiveCTE do
       cte << rel2
 
       sql = cte.to_arel.to_sql
-      name = ActiveRecord::Base.connection.quote_table_name(:cte_name)
+      name = ApplicationRecord.connection.quote_table_name(:cte_name)
 
-      sql1, sql2 = ActiveRecord::Base.connection.unprepared_statement do
+      sql1, sql2 = ApplicationRecord.connection.unprepared_statement do
         [rel1.except(:order).to_sql, rel2.except(:order).to_sql]
       end
 
@@ -28,8 +28,8 @@ RSpec.describe Gitlab::SQL::RecursiveCTE do
     it 'returns an alias for the CTE' do
       table = Arel::Table.new(:kittens)
 
-      source_name = ActiveRecord::Base.connection.quote_table_name(:cte_name)
-      alias_name = ActiveRecord::Base.connection.quote_table_name(:kittens)
+      source_name = ApplicationRecord.connection.quote_table_name(:cte_name)
+      alias_name = ApplicationRecord.connection.quote_table_name(:kittens)
 
       expect(cte.alias_to(table).to_sql).to eq("#{source_name} AS #{alias_name}")
     end
@@ -37,8 +37,8 @@ RSpec.describe Gitlab::SQL::RecursiveCTE do
     it 'replaces dots with an underscore' do
       table = Arel::Table.new('gitlab.kittens')
 
-      source_name = ActiveRecord::Base.connection.quote_table_name(:cte_name)
-      alias_name = ActiveRecord::Base.connection.quote_table_name(:gitlab_kittens)
+      source_name = ApplicationRecord.connection.quote_table_name(:cte_name)
+      alias_name = ApplicationRecord.connection.quote_table_name(:gitlab_kittens)
 
       expect(cte.alias_to(table).to_sql).to eq("#{source_name} AS #{alias_name}")
     end

spec/lib/gitlab/utils/usage_data_spec.rb

@@ -41,10 +41,10 @@ RSpec.describe Gitlab::Utils::UsageData do
 
   describe '#estimate_batch_distinct_count' do
     let(:error_rate) { Gitlab::Database::PostgresHll::BatchDistinctCounter::ERROR_RATE } # HyperLogLog is a probabilistic algorithm, which provides estimated data, with given error margin
-    let(:relation) { double(:relation) }
+    let(:relation) { double(:relation, connection: double(:connection)) }
 
     before do
-      allow(ActiveRecord::Base.connection).to receive(:transaction_open?).and_return(false)
+      allow(ActiveRecord::Base.connection).to receive(:transaction_open?).and_return(false) # rubocop: disable Database/MultipleDatabases
     end
 
     it 'delegates counting to counter class instance' do
@@ -95,6 +95,10 @@ RSpec.describe Gitlab::Utils::UsageData do
       let(:build_needs_estimated_cardinality) { 5.217656147118495 }
       let(:ci_builds_estimated_cardinality) { 2.0809220082170614 }
 
+      before do
+        allow(ActiveRecord::Base.connection).to receive(:transaction_open?).and_return(false) # rubocop: disable Database/MultipleDatabases
+      end
+
       context 'different counting parameters' do
         before_all do
           1.upto(3) { |i| create(:ci_build_need, name: i, build: build) }

spec/models/concerns/case_sensitivity_spec.rb

@@ -4,7 +4,7 @@ require 'spec_helper'
 
 RSpec.describe CaseSensitivity do
   describe '.iwhere' do
-    let_it_be(:connection) { ActiveRecord::Base.connection }
+    let_it_be(:connection) { Namespace.connection }
     let_it_be(:model) do
       Class.new(ActiveRecord::Base) do
         include CaseSensitivity

spec/models/concerns/sortable_spec.rb

@@ -70,8 +70,8 @@ RSpec.describe Sortable do
       it 'ascending' do
         expect(relation).to receive(:reorder).once.and_call_original
 
-        table = Regexp.escape(ActiveRecord::Base.connection.quote_table_name(:namespaces))
-        column = Regexp.escape(ActiveRecord::Base.connection.quote_column_name(:name))
+        table = Regexp.escape(ApplicationRecord.connection.quote_table_name(:namespaces))
+        column = Regexp.escape(ApplicationRecord.connection.quote_column_name(:name))
 
         sql = relation.order_by('name_asc').to_sql
 
@@ -81,8 +81,8 @@ RSpec.describe Sortable do
       it 'descending' do
         expect(relation).to receive(:reorder).once.and_call_original
 
-        table = Regexp.escape(ActiveRecord::Base.connection.quote_table_name(:namespaces))
-        column = Regexp.escape(ActiveRecord::Base.connection.quote_column_name(:name))
+        table = Regexp.escape(ApplicationRecord.connection.quote_table_name(:namespaces))
+        column = Regexp.escape(ApplicationRecord.connection.quote_column_name(:name))
 
         sql = relation.order_by('name_desc').to_sql
 

spec/models/concerns/where_composite_spec.rb

@@ -8,7 +8,7 @@ RSpec.describe WhereComposite do
 
     let(:model) do
       tbl_name = test_table_name
-      Class.new(ActiveRecord::Base) do
+      Class.new(ApplicationRecord) do
         self.table_name = tbl_name
 
         include WhereComposite
@@ -16,7 +16,7 @@ RSpec.describe WhereComposite do
     end
 
     def connection
-      ActiveRecord::Base.connection
+      ApplicationRecord.connection
     end
 
     before_all do

spec/models/experiment_spec.rb

@@ -258,7 +258,7 @@ RSpec.describe Experiment do
         let(:variant) { :experimental }
 
         it 'does not initiate a transaction' do
-          expect(ActiveRecord::Base.connection).not_to receive(:transaction)
+          expect(Experiment.connection).not_to receive(:transaction)
 
           subject
         end
@@ -360,7 +360,7 @@ RSpec.describe Experiment do
         let(:context) { {} }
 
         it 'does not initiate a transaction' do
-          expect(ActiveRecord::Base.connection).not_to receive(:transaction)
+          expect(Experiment.connection).not_to receive(:transaction)
 
           subject
         end

spec/models/internal_id_spec.rb

@@ -88,7 +88,7 @@ RSpec.describe InternalId do
 
       context 'when executed outside of transaction' do
         it 'increments counter with in_transaction: "false"' do
-          allow(ActiveRecord::Base.connection).to receive(:transaction_open?) { false }
+          allow(ActiveRecord::Base.connection).to receive(:transaction_open?) { false } # rubocop: disable Database/MultipleDatabases
 
           expect(InternalId.internal_id_transactions_total).to receive(:increment)
             .with(operation: :generate, usage: 'issues', in_transaction: 'false').and_call_original
@@ -147,7 +147,7 @@ RSpec.describe InternalId do
         let(:value) { 2 }
 
         it 'increments counter with in_transaction: "false"' do
-          allow(ActiveRecord::Base.connection).to receive(:transaction_open?) { false }
+          allow(ActiveRecord::Base.connection).to receive(:transaction_open?) { false } # rubocop: disable Database/MultipleDatabases
 
           expect(InternalId.internal_id_transactions_total).to receive(:increment)
             .with(operation: :reset, usage: 'issues', in_transaction: 'false').and_call_original
@@ -218,7 +218,7 @@ RSpec.describe InternalId do
 
       context 'when executed outside of transaction' do
         it 'increments counter with in_transaction: "false"' do
-          allow(ActiveRecord::Base.connection).to receive(:transaction_open?) { false }
+          allow(ActiveRecord::Base.connection).to receive(:transaction_open?) { false } # rubocop: disable Database/MultipleDatabases
 
           expect(InternalId.internal_id_transactions_total).to receive(:increment)
             .with(operation: :track_greatest, usage: 'issues', in_transaction: 'false').and_call_original

spec/workers/analytics/usage_trends/counter_job_worker_spec.rb

@@ -11,7 +11,7 @@ RSpec.describe Analytics::UsageTrends::CounterJobWorker do
   let(:job_args) { [users_measurement_identifier, user_1.id, user_2.id, recorded_at] }
 
   before do
-    allow(ActiveRecord::Base.connection).to receive(:transaction_open?).and_return(false)
+    allow(::Analytics::UsageTrends::Measurement.connection).to receive(:transaction_open?).and_return(false)
   end
 
   include_examples 'an idempotent worker' do

spec/workers/users/create_statistics_worker_spec.rb

@@ -7,7 +7,7 @@ RSpec.describe Users::CreateStatisticsWorker do
     subject { described_class.new.perform }
 
     before do
-      allow(ActiveRecord::Base.connection).to receive(:transaction_open?).and_return(false)
+      allow(UsersStatistics.connection).to receive(:transaction_open?).and_return(false)
     end
 
     context 'when successful' do