1 files changed, 91 insertions, 0 deletions
diff --git a/lib/gitlab/database/async_constraints/validators/base.rb b/lib/gitlab/database/async_constraints/validators/base.rb
new file mode 100644
index 00000000000..39a72955d63
--- /dev/null
+++ b/lib/gitlab/database/async_constraints/validators/base.rb
@@ -0,0 +1,91 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    module AsyncConstraints
+      module Validators
+        class Base
+          include AsyncDdlExclusiveLeaseGuard
+          extend ::Gitlab::Utils::Override
+
+          TIMEOUT_PER_ACTION = 1.day
+          STATEMENT_TIMEOUT = 12.hours
+
+          def initialize(record)
+            @record = record
+          end
+
+          def perform
+            try_obtain_lease do
+              if constraint_exists?
+                log_info('Starting to validate constraint')
+                validate_constraint_with_error_handling
+                log_info('Finished validating constraint')
+              else
+                log_info(skip_log_message)
+                record.destroy!
+              end
+            end
+          end
+
+          private
+
+          attr_reader :record
+
+          delegate :connection, :name, :table_name, :connection_db_config, to: :record
+
+          def constraint_exists?; end
+
+          def validate_constraint_with_error_handling
+            validate_constraint
+            record.destroy!
+          rescue StandardError => error
+            record.handle_exception!(error)
+
+            Gitlab::ErrorTracking.track_and_raise_for_dev_exception(error)
+            Gitlab::AppLogger.error(message: error.message, **logging_options)
+          end
+
+          def validate_constraint
+            set_statement_timeout do
+              connection.execute(<<~SQL.squish)
+                ALTER TABLE #{connection.quote_table_name(table_name)}
+                VALIDATE CONSTRAINT #{connection.quote_column_name(name)};
+              SQL
+            end
+          end
+
+          def set_statement_timeout
+            connection.execute(format("SET statement_timeout TO '%ds'", STATEMENT_TIMEOUT))
+            yield
+          ensure
+            connection.execute('RESET statement_timeout')
+          end
+
+          def lease_timeout
+            TIMEOUT_PER_ACTION
+          end
+
+          def log_info(message)
+            Gitlab::AppLogger.info(message: message, **logging_options)
+          end
+
+          def skip_log_message
+            "Skipping #{name} validation since it does not exist. " \
+              "The queuing entry will be deleted"
+          end
+
+          def logging_options
+            {
+              class: self.class.name.to_s,
+              connection_name: database_config_name,
+              constraint_name: name,
+              constraint_type: record.constraint_type,
+              table_name: table_name
+            }
+          end
+        end
+      end
+    end
+  end
+end