umqtt 断连后，重新连接，能够收到发送数据的应答，没有收到应答心跳

1. 刚开始是传送数据，出现umqtt发送失败。后来是收到连接失败了，需要重新连接服务器
   1）server fin ack! connect failed! need to reconnect!

02-27 20:11:26.572 192.168.1.73:64656-> D/evcsi_trans: mqtt recv packet topic[6] seq[3] ret[10] data:success

02-27 20:11:26.649 192.168.1.73:64656-> D/evcsi_trans: pub topic[6]:s/test_6x8si9jf4h/thing/event/dc/charge/property/post, seq:4, gun:1

02-27 20:11:26.651 192.168.1.73:64656-> E/umqtt: publish trans send failed!

02-27 20:11:31.391 192.168.1.73:64656-> D/evcsi_trans: mqtt recv packet topic[6] seq[3] ret[10] data:success

02-27 20:11:31.449 192.168.1.73:64656-> D/evcsi_trans: pub topic[6]:s/test_6x8si9jf4h/thing/event/dc/charge/property/post, seq:5, gun:1

02-27 20:11:31.450 192.168.1.73:64656-> I/umqtt: publish qos1 ack success!

02-27 20:11:31.618 192.168.1.73:64656-> W/umqtt: server fin ack! connect failed! need to reconnect!

02-27 20:11:31.624 192.168.1.73:64656-> W/umqtt: reconnect start! stop timer -> trans disconnect delay 5000ms -> umqtt connect!

02-27 20:11:36.461 192.168.1.73:64656-> E/evcsi_trans: tx packet:6 timeout

02-27 20:11:36.463 192.168.1.73:64656-> D/evcsi_trans: pub topic[6]:s/test_6x8si9jf4h/thing/event/dc/charge/property/post, seq:5, gun:1

02-27 20:11:36.464 192.168.1.73:64656-> E/umqtt: publish trans send failed!

02-27 20:11:36.798 192.168.1.73:64656-> I/umqtt: connect success!

1. 再后来就只发送数据成功应答，但是没有收到服务器的心跳返回。

02-27 20:26:56.382 192.168.1.73:64656-> E/evcsi_trans: tx packet:7 timeout

02-27 20:26:56.382 192.168.1.73:64656-> D/evcsi_trans: pub topic[7]:s/test_6x8si9jf4h/thing/event/dc/property/post, seq:4, gun:1

02-27 20:26:56.383 192.168.1.73:64656-> I/umqtt: publish qos1 ack success!

02-27 20:27:01.399 192.168.1.73:64656-> E/evcsi_trans: tx packet:7 timeout

02-27 20:27:01.402 192.168.1.73:64656-> D/evcsi_trans: pub topic[7]:s/test_6x8si9jf4h/thing/event/dc/property/post, seq:4, gun:1

02-27 20:27:06.388 192.168.1.73:64656-> E/evcsi_trans: tx packet:7 timeout

02-27 20:27:06.493 192.168.1.73:64656-> I/umqtt: publish qos1 ack success!

02-27 20:27:11.489 192.168.1.73:64656-> E/evcsi_trans: tx packet:10 timeout

02-27 20:27:11.490 192.168.1.73:64656-> I/umqtt: publish qos1 ack success!

02-27 20:27:16.492 192.168.1.73:64656-> E/evcsi_trans: tx packet:10 timeout

02-27 20:27:16.493 192.168.1.73:64656-> I/umqtt: publish qos1 ack success!

02-27 20:27:21.504 192.168.1.73:64656-> E/evcsi_trans: tx packet:10 timeout

02-27 20:27:21.507 192.168.1.73:64656-> I/umqtt: publish qos1 ack success!
3.可能是什么原因？
umqtt 已经没有发送心跳了？所以服务器没有应答。
02-27 20:38:16.685 192.168.1.73:64656-> I/umqtt: ping resp! broker -> client! now tick: 33351