Merge branch '382033-force-partition-attach' into 'master'

Force partition attachment to happen during the weekend

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/121554



Merged-by: Simon Tomlinson <stomlinson@gitlab.com>
Approved-by: Simon Tomlinson <stomlinson@gitlab.com>
Approved-by: Tianwen Chen <tchen@gitlab.com>
Reviewed-by: Marius Bobin <mbobin@gitlab.com>
Reviewed-by: Tianwen Chen <tchen@gitlab.com>
Co-authored-by: Marius Bobin <mbobin@gitlab.com>

config/feature_flags/development/attach_ci_builds_partition.yml

+---
+name: attach_ci_builds_partition
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/121554
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/382033
+milestone: '16.1'
+type: development
+group: group::pipeline execution
+default_enabled: false

lib/gitlab/database/ci_builds_partitioning.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    class CiBuildsPartitioning
+      include AsyncDdlExclusiveLeaseGuard
+
+      ATTEMPTS = 10
+      LOCK_TIMEOUT = 10.seconds
+      LEASE_TIMEOUT = 35.minutes
+
+      def initialize(logger: Gitlab::AppLogger)
+        @connection = ::Ci::ApplicationRecord.connection
+        @timing_configuration = Array.new(ATTEMPTS) { [LOCK_TIMEOUT, rand((1.minute)..(3.minutes))] }
+        @logger = logger
+      end
+
+      def execute
+        return unless can_execute?
+
+        try_obtain_lease do
+          lock_retries.run(raise_on_exhaustion: true) do
+            connection.execute(partitioning_sql)
+          end
+
+          log_info('Partition attached')
+        end
+
+      rescue WithLockRetries::AttemptsExhaustedError
+        log_info('Failed to attach partition')
+      end
+
+      private
+
+      attr_reader :connection, :timing_configuration, :logger
+
+      def can_execute?
+        return false if process_disabled?
+        return false unless Gitlab.com?
+        return false unless connection.table_exists?(:p_ci_builds)
+
+        if already_attached?
+          log_info('Table already attached')
+
+          return false
+        end
+
+        if vacuum_running?
+          log_info('Autovacuum detected')
+
+          return false
+        end
+
+        true
+      end
+
+      def process_disabled?
+        ::Feature.disabled?(:attach_ci_builds_partition)
+      end
+
+      def already_attached?
+        Gitlab::Database::SharedModel.using_connection(connection) do
+          Gitlab::Database::PostgresPartition
+            .for_parent_table('public.p_ci_builds')
+            .for_identifier('public.ci_builds')
+            .exists?
+        end
+      end
+
+      def vacuum_running?
+        Gitlab::Database::SharedModel.using_connection(connection) do
+          Gitlab::Database::PostgresAutovacuumActivity
+            .for_tables(%i[ci_pipelines ci_stages ci_builds ci_resource_groups])
+            .any?
+        end
+      end
+
+      def lock_retries
+        Gitlab::Database::WithLockRetries.new(
+          timing_configuration: timing_configuration,
+          connection: connection,
+          logger: logger,
+          klass: self.class
+        )
+      end
+
+      def partitioning_sql
+        <<~SQL.squish
+          SET LOCAL statement_timeout TO '11s';
+
+          LOCK ci_pipelines, ci_stages, ci_builds, ci_resource_groups IN ACCESS EXCLUSIVE MODE;
+
+          DROP TRIGGER IF EXISTS ci_builds_loose_fk_trigger ON ci_builds;
+
+          ALTER TABLE p_ci_builds ATTACH PARTITION ci_builds FOR VALUES IN (100);
+
+          ALTER SEQUENCE ci_builds_id_seq OWNED BY p_ci_builds.id;
+          ALTER TABLE p_ci_builds DROP CONSTRAINT partitioning_constraint;
+
+          CREATE TRIGGER ci_builds_loose_fk_trigger
+            AFTER DELETE ON ci_builds
+            REFERENCING OLD TABLE AS old_table
+            FOR EACH STATEMENT EXECUTE FUNCTION insert_into_loose_foreign_keys_deleted_records();
+
+          CREATE TRIGGER p_ci_builds_loose_fk_trigger
+            AFTER DELETE ON p_ci_builds
+            REFERENCING OLD TABLE AS old_table
+            FOR EACH STATEMENT EXECUTE FUNCTION insert_into_loose_foreign_keys_deleted_records();
+        SQL
+      end
+
+      def log_info(message)
+        logger.info(message: message, class: self.class.to_s)
+      end
+
+      def connection_db_config
+        ::Ci::ApplicationRecord.connection_db_config
+      end
+
+      def lease_timeout
+        LEASE_TIMEOUT
+      end
+    end
+  end
+end

lib/tasks/gitlab/db.rake

@@ -241,6 +241,7 @@ namespace :gitlab do
         exit
       end
 
+      Gitlab::Database::CiBuildsPartitioning.new.execute
       Gitlab::Database::Reindexing.invoke
     end