def _failover_writer()

in aws_advanced_python_wrapper/failover_plugin.py [0:0]
38 lines of code
11 McCabe index (conditional complexity)

    def _failover_writer(self):
        telemetry_factory = self._plugin_service.get_telemetry_factory()
        context = telemetry_factory.open_telemetry_context("failover to writer host", TelemetryTraceLevel.NESTED)
        self._failover_writer_triggered_counter.inc()

        try:
            logger.info("FailoverPlugin.StartWriterFailover")

            result: WriterFailoverResult = self._writer_failover_handler.failover(self._plugin_service.all_hosts)
            if result is not None and result.exception is not None:
                raise result.exception
            elif result is None or not result.is_connected:
                raise FailoverFailedError(Messages.get("FailoverPlugin.UnableToConnectToWriter"))

            writer_host = self._get_writer(result.topology)
            allowed_hosts = self._plugin_service.hosts
            allowed_hostnames = [host.host for host in allowed_hosts]
            if writer_host.host not in allowed_hostnames:
                raise FailoverFailedError(
                    Messages.get_formatted(
                        "FailoverPlugin.NewWriterNotAllowed",
                        "<null>" if writer_host is None else writer_host.host,
                        LogUtils.log_topology(allowed_hosts)))

            self._plugin_service.set_current_connection(result.new_connection, writer_host)
            logger.info("FailoverPlugin.EstablishedConnection", self._plugin_service.current_host_info)

            self._plugin_service.refresh_host_list()

            self._failover_writer_success_counter.inc()
        except FailoverSuccessError as fse:
            context.set_success(True)
            context.set_exception(fse)
            self._failover_writer_success_counter.inc()
            raise fse
        except Exception as ex:
            context.set_success(False)
            context.set_exception(ex)
            self._failover_writer_failed_counter.inc()
            raise ex
        finally:
            context.close_context()
            if self._telemetry_failover_additional_top_trace_setting:
                telemetry_factory.post_copy(context, TelemetryTraceLevel.FORCE_TOP_LEVEL)