# Mqtt publish qos 0 working but when using qos 1, return publish failure

**URL:** <https://forums.freertos.org/t/mqtt-publish-qos-0-working-but-when-using-qos-1-return-publish-failure/13632>\
**Category:** Libraries\
**Created:** [October 6, 2021, 5:19am UTC](https://forums.freertos.org/t/mqtt-publish-qos-0-working-but-when-using-qos-1-return-publish-failure/13632 "2021-10-06T05:19:38Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**Author:** ![jiangpen](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/jiangpen/32/1942_2.png) [@jiangpen](https://forums.freertos.org/u/jiangpen)\
**Post date:** [October 6, 2021, 5:19am UTC](https://forums.freertos.org/t/mqtt-publish-qos-0-working-but-when-using-qos-1-return-publish-failure/13632/1 "2021-10-06T05:19:38Z")

</div>

I ported the FreeRTOS 20210700 to STM32, when I used none-agent version mqtt to publish to AWS, if set qos0, then it is working fine and reliable. But when I use qos1, the it shows publish failed.  
When I use the OTA which is agent version of MQTT, the publish is failed, I found it is using qos1 too.  
May I know if any setting affect this?

requestJob\_Mqtt:Failed to publish MQTT message:publish returned error: OtaMqttStatus\_t=OtaMqttPublishFailed  
Failed to subscribe to MQTT topic: subscribe returned error: OtaMqttStatus\_t=OtaMqttSubscribeFailed, topic=$aws/things/350999901/jobs/notify-next

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<div class="post-metadata">

**Author:** ![aggarg](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/aggarg/32/4245_2.png) [@aggarg](https://forums.freertos.org/u/aggarg)\
**Post date:** [October 6, 2021, 11:36pm UTC](https://forums.freertos.org/t/mqtt-publish-qos-0-working-but-when-using-qos-1-return-publish-failure/13632/2 "2021-10-06T23:36:36Z")

</div>

Which STM32 platfrom are you porting to? Can you enable MQTT debug logs and share logs? You’ll need to changes your `core_mqtt_config.h` file: [https://github.com/aws/amazon-freertos/blob/main/vendors/st/boards/stm32l475\_discovery/aws\_demos/config\_files/core\_mqtt\_config.h#L44](https://github.com/aws/amazon-freertos/blob/main/vendors/st/boards/stm32l475_discovery/aws_demos/config_files/core_mqtt_config.h#L44)

Thanks.

---

<div class="post-metadata">

**Author:** ![jiangpen](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/jiangpen/32/1942_2.png) [@jiangpen](https://forums.freertos.org/u/jiangpen)\
**Post date:** [October 7, 2021, 5:07am UTC](https://forums.freertos.org/t/mqtt-publish-qos-0-working-but-when-using-qos-1-return-publish-failure/13632/3 "2021-10-07T05:07:12Z")

</div>

thanks aggarg, I port to STM32H7 with LwIP stack. I can connect to AWS and report using none-agent mqtt version with qos 0.  
then I run the code of agent version mqtt:

here is some logs when I run the simple\_sub\_pub\_demo.c  
It seems the prvPublishCommandCallback never got called.  
I know it maybe my port issue as the windows simulator works, so it should not be a problem of mqtt agent. Any hints is great.

```auto
simple_sub_pub_demo. +387 prvSubscribeToTopic Sending subscribe request to agent for topic filter: /filter/Publisher0 with id 1
simple_sub_pub_demo. +414 prvSubscribeToTopic Received subscribe ack for topic /filter/Publisher0 containing ID 1
simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 0" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 0 to complete.
simple_sub_pub_demo. +516 prvSimpleSubscribePublish Demo completed successfully. 0, 0

simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 1" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 1 to complete.
configASSERT:../Core/MQTT_Agent/simple_sub_pub_demo.c:513

```

---

<div class="post-metadata">

**Author:** ![aggarg](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/aggarg/32/4245_2.png) [@aggarg](https://forums.freertos.org/u/aggarg)\
**Post date:** [October 7, 2021, 5:33am UTC](https://forums.freertos.org/t/mqtt-publish-qos-0-working-but-when-using-qos-1-return-publish-failure/13632/4 "2021-10-07T05:33:24Z")

</div>

> [@jiangpen](#):
>
> It seems the prvPublishCommandCallback never got called.

prvPublishCommandCallback should get called [from here](https://github.com/FreeRTOS/coreMQTT-Agent/blob/main/source/core_mqtt_agent.c#L780) which should get called when `MQTT_ProcessLoop` is called [here](https://github.com/FreeRTOS/coreMQTT-Agent/blob/main/source/core_mqtt_agent.c#L584). Are you calling `MQTTAgent_CommandLoop` function in a loop [like here](https://github.com/aws/amazon-freertos/blob/main/demos/coreMQTT_Agent/mqtt_agent_task.c#L856)?

Can you set breakpoints at above three locations to see where is it failing?

Thanks.

---

<div class="post-metadata">

**Author:** ![jiangpen](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/jiangpen/32/1942_2.png) [@jiangpen](https://forums.freertos.org/u/jiangpen)\
**Post date:** [October 7, 2021, 7:27am UTC](https://forums.freertos.org/t/mqtt-publish-qos-0-working-but-when-using-qos-1-return-publish-failure/13632/5 "2021-10-07T07:27:04Z")

</div>

it appears stuck in MQTT\_ProcessLoop. But first time call, it is OK, then not returning.  
I suspect there is some socket option on receives etc, as I change to use LwIP stack.  
here is the logs: (Interesting to see number 8 package actual reaches AWS IoT )  
It looks like QoS 0 does not need reply, so it works, but when get QoS 1, it needs ACK, then stop working. Stuck in readFunc in MQTT\_GetIncomingPacketTypeAndLength:  
Really appreciate if can shot further light on it. thanks  
MQTTStatus\_t MQTT\_GetIncomingPacketTypeAndLength( TransportRecv\_t readFunc,  
NetworkContext\_t \* pNetworkContext,  
MQTTPacketInfo\_t \* pIncomingPacket )  
{

```
else
{
    /* Read a single byte. */

```

**//hang here**  
bytesReceived = readFunc( pNetworkContext,  
&( pIncomingPacket-\>type ),  
1U );

```auto
mtd_mqtt_agent.c +524 prvSocketConnect prvConnectToServerWithBackoffRetries
sockets_wrapper.c +155 Sockets_Connect Established TCP connection with a2l4ym2rlvj63k-ats.iot.ap-southeast-2.amazonaws.com. socket=0, ip=-898623485
core_mqtt.c +886 receivePacket Packet received. ReceivedBytes=2.
core_mqtt_serializer +969 deserializeConnack CONNACK session present bit not set.
core_mqtt_serializer +911 logConnackResponse Connection accepted.
core_mqtt.c +1566 receiveConnack Received MQTT CONNACK successfully from broker.
core_mqtt.c +1832 MQTT_Connect MQTT connection established with the broker.
mtd_mqtt_agent.c +393 prvMQTTConnect Session present: 0

simple_sub_pub_demo. +387 prvSubscribeToTopic Sending subscribe request to agent for topic filter: /filter/Publisher0 with id 1
core_mqtt.c +886 receivePacket Packet received. ReceivedBytes=3.
simple_sub_pub_demo. +414 prvSubscribeToTopic Received subscribe ack for topic /filter/Publisher0 containing ID 1
simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 0" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 0 to complete.
simple_sub_pub_demo. +516 prvSimpleSubscribePublish Demo completed successfully. 0, 0

simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 1" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 1 to complete.
simple_sub_pub_demo. +516 prvSimpleSubscribePublish Demo completed successfully. 0, 1

simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 2" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 2 to complete.
simple_sub_pub_demo. +516 prvSimpleSubscribePublish Demo completed successfully. 0, 2

simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 3" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 3 to complete.
simple_sub_pub_demo. +516 prvSimpleSubscribePublish Demo completed successfully. 0, 3

simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 4" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 4 to complete.
simple_sub_pub_demo. +516 prvSimpleSubscribePublish Demo completed successfully. 0, 4

simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 5" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 5 to complete.
simple_sub_pub_demo. +516 prvSimpleSubscribePublish Demo completed successfully. 0, 5

simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 6" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 6 to complete.
simple_sub_pub_demo. +516 prvSimpleSubscribePublish Demo completed successfully. 0, 6

simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 7" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 7 to complete.
simple_sub_pub_demo. +516 prvSimpleSubscribePublish Demo completed successfully. 0, 7

simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 8" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 8 to complete.
core_mqtt_serializer +2399 MQTT_GetIncomingPacketTyp A single byte was not read from the transport: transportStatus=-30848.
core_mqtt.c +1322 receiveSingleIteration Receiving incoming packet length failed. Status=MQTTRecvFailed
core_mqtt.c +2194 MQTT_ProcessLoop Exiting process loop due to failure: ErrorStatus=MQTTRecvFailed
core_mqtt_agent.c +1025 MQTTAgent_CommandLoop MQTT operation failed with status MQTTRecvFailed

mtd_mqtt_agent.c +676 prvMQTTAgentTask WARN: MQTTAgent_CommandLoop return 4
mtd_mqtt_agent.c +616 prvSocketDisconnect Disconnecting TLS connection.

mtd_mqtt_agent.c +524 prvSocketConnect prvConnectToServerWithBackoffRetries
sockets_wrapper.c +155 Sockets_Connect Established TCP connection with a2l4ym2rlvj63k-ats.iot.ap-southeast-2.amazonaws.com. socket=1, ip=-1185728755
core_mqtt.c +886 receivePacket Packet received. ReceivedBytes=2.
core_mqtt_serializer +969 deserializeConnack CONNACK session present bit not set.
core_mqtt_serializer +911 logConnackResponse Connection accepted.
core_mqtt.c +1566 receiveConnack Received MQTT CONNACK successfully from broker.
core_mqtt.c +1832 MQTT_Connect MQTT connection established with the broker.
mtd_mqtt_agent.c +393 prvMQTTConnect Session present: 0

mtd_mqtt_agent.c +444 prvHandleResubscribe Resubscribe to the topic /filter/Publisher0 will be attempted.
core_mqtt.c +886 receivePacket Packet received. ReceivedBytes=2.
core_mqtt.c +1164 handlePublishAcks Ack packet deserialized with result: MQTTSuccess.
core_mqtt.c +1177 handlePublishAcks State record updated. New state=MQTTPublishDone.
simple_sub_pub_demo. +245 prvPublishCommandCallback prvPublishCommandCallback 0.

simple_sub_pub_demo. +516 prvSimpleSubscribePublish Demo completed successfully. 8, 8

simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 9" on topic "/filter/Publisher0"
simple_sub_pub_demo. +505 prvSimpleSubscribePublish Task Publisher0 waiting for publish 9 to complete.
simple_sub_pub_demo. +516 prvSimpleSubscribePublish Demo completed successfully. 8, 9

simple_sub_pub_demo. +490 prvSimpleSubscribePublish Sending publish request to agent with message "Publisher0 publishing message 10" on topic "/filter/Publisher0"
freertos_command_poo +119 Agent_GetCommand No command structure available.
configASSERT:../Core/MQTT_Agent/simple_sub_pub_demo.c:501

```

---

<div class="post-metadata">

**Author:** ![aggarg](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/aggarg/32/4245_2.png) [@aggarg](https://forums.freertos.org/u/aggarg)\
**Post date:** [October 7, 2021, 5:43pm UTC](https://forums.freertos.org/t/mqtt-publish-qos-0-working-but-when-using-qos-1-return-publish-failure/13632/6 "2021-10-07T17:43:10Z")

</div>

> [@jiangpen](#):
>
> `A single byte was not read from the transport: transportStatus=-30848.`

Seems like an error in receive. Can you check what this error code means?

> [@jiangpen](#):
>
> `freertos_command_poo +119 Agent_GetCommand No command structure available.`

You probably need to increase`MQTT_COMMAND_CONTEXTS_POOL_SIZE`. For debugging, you can reduce the number of publisher tasks and enable them later once you get one task working.

> [@jiangpen](#):
>
> `configASSERT:../Core/MQTT_Agent/simple_sub_pub_demo.c:501`

Seems like you are hitting an assert. What is this assert?

Thanks.

---

<div class="post-metadata">

**Author:** ![abrinao](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/abrinao/32/735_2.png) [@abrinao](https://forums.freertos.org/u/abrinao)\
**Post date:** [October 8, 2021, 12:31am UTC](https://forums.freertos.org/t/mqtt-publish-qos-0-working-but-when-using-qos-1-return-publish-failure/13632/7 "2021-10-08T00:31:35Z")

</div>

Another thing to try. You are right in that QoS1 will definitely take more time because you will need to send a `PUBACK` to the broker in addition to just receiving the actual message. Although, it seems you mentioned that you are stuck at the `recv` call, and this can happen when the transport recv function has no configured timeout. Have you enabled `LWIP_SO_RCVTIMEO` and used `netconn_set_recvtimeout` to set the recv timeout of the socket as shown in this [tutorial](https://lwip.fandom.com/wiki/Netconn_receive_timeout)? You will likely want to do the same for send.

---

<div class="post-metadata">

**Author:** ![jiangpen](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/jiangpen/32/1942_2.png) [@jiangpen](https://forums.freertos.org/u/jiangpen)\
**Post date:** [October 8, 2021, 3:28am UTC](https://forums.freertos.org/t/mqtt-publish-qos-0-working-but-when-using-qos-1-return-publish-failure/13632/8 "2021-10-08T03:28:27Z")

</div>

thanks @aggarg and @abrinao ,  
today I solved this problem.  
The reason is when I port the lwIP, the socket set\_option parameter takes the one from FreeRTOS Plus stack. But they have different defines. After I set the socket option timeout correctly, it is working now.  
The stuck of recv call is because timeout does not work, and it hang there.  
Thanks again.