CoAP client sample - send command freezes after a few iterations

[Lukáš]

Hi,

as discussed in different issue on DevZone. We have discovered that send command freezes the program in the CoAP client sample. The Nordic employee Hakon has confirmed that it also happens on his board.

Could you please try to inspect the issue? Unfortunately, we are not able to collect the modem trace right now our DK broke up and we are not able to collect traces on our custom board.

The modified sample could be downloaded under this link: devzone.nordicsemi.com/.../coap_5F00_client.zip

[Hakon]

Hi there,

I will report this internally as a potential bug. Some delay in response time is to be expected as many staff members are still on vacation.

[Lukáš]

Hi Hakon, I know that many your collegues are still on vacation. But could you please try to push this issue? It is something that we reported already month ago and in our app, it is critical issue because it freezes the whole device. And it is not possible to recover. 

[Lukáš]

Hi, any update on this, please? We just discovered that when we set the socket for non-blocking operation using nrf_fcntl() then it won't freeze all day long. However, the non-blocking socket has much worse performance in terms of connection stability and message latency. Ideas?

[Heidi]

Hi, no there is no update on this yet, unfortunately. 

[Lukáš]

Heidi, I apologize for putting the pressure on you. However, is there anything we can do to speed up the process? For us, it is now a blocker issue because the whole app freezes and then the device couldn't be used.

[Heidi]

Hi, I understand. The person responsible for the CoAP client sample isn't back from vacation until Monday the 17th, but I will try to find someone else who can take a look at this.

I believe taking a modem trace would be the best course of action. What is the reason you aren't able to take one on your custom board? Perhaps we can work around it. 

[Lukáš]

Hi, I think that this has nothing to do with the CoAP client sample. It is more likely bsdlib issue (see the note about blocking and non-blocking options).

Heidi said:

What is the reason you aren't able to take one on your custom board? Perhaps we can work around it. 

We would be very happy if we could capture the modem trace. However, we have not found a solution on how to do this on our custom board. The trace from nRF9160 could be gathered only on UART. 

In our setup, we use nRF9160 and nRF52820 that are wired via one UART interface, so we don't know how to pass the trace through it without completely rewriting the application. If there would be an interface from Nordic on how to save the trace to the internal/external flash, so it could be sent via Bluetooth/LTE afterward, it would greatly help us.