code: private boolean ackNoException(Channel consumerChannel, boolean msgApplied, final long deliveryTag) {
          try {
              if (msgApplied) {
                  //设置multiple为true，经过压测发现有一定几率ack出现ioException的情况，这里顺带把前面的消息一起ack掉
                  consumerChannel.basicAck(deliveryTag, true);
              } else {
                  consumerChannel.basicNack(deliveryTag, false, true);
              }
              return true;
          } catch (Throwable unknownException) {
              LOG.error(unknownException);
              return false;
          }
      }
docs: ack，如果出现异常，那么只打印日志不抛出异常