Getting ERROR: getaddrinfo failed -11 in MQTT connection

[Adeel]

Hi Dev team,

I have been working with the MQTT example and building up my application. I establish a successful connection with the broker and everything runs fine for 5-6 days. Then I get the (ERROR: getaddrinfo failed -11 ) error and the MQTT connection does not happen. I looked into the code and found that this error is because the broker's address is not obtained. 

I looked into the errno and found that -11 refers to "No more processes". 

I could not understand why this error comes up suddenly and how could I solve this issue.

Its strange because it comes up after things have been running smoothly. 

Regards,

Adeel.

[Øyvind]

Hi Adeel,

can you please provide more output from the log? What MQTT broker are you trying to connect? What is the MQTT keepalive set to?

Thanks.
-Øyvind

[Adeel]

Hi Oyvind,

I am connecting to a firm's broker and not the open source brokers like HIVE MQ. The connection works perfectly for 6-7 days, probably more than that (there is no specific fixed period after which I get this error).

The keepalive is set to: 60 seconds. I am normally connecting to the MQTT broker after every hour, sending the data and then disconnecting from the broker.

I just wanted to know what this addrinfo failed -11 means, as I get it just when the MQTT wants to connect to the broker.

Regards,

Adeel.

[Adeel]

Hi Oyvind,

Yes the broker is online. I verified that as I could connect to it through MQTT.fx . Also, out of the 5 devices that I have, 3 had this getaddrinfo failed issue while the other 2 were working perfectly. I had started all 5 of them at the same time. 

Could it be due to the SIM ? I have sim from 1NCE in all my Thingys. 

Regards,

Adeel.

[Øyvind]

Adeel, 

Adeel said:

Could it be due to the SIM ? I have sim from 1NCE in all my Thingys.

Are you using PSM/eDRX? If you are not able to provide modem trace, are you able to provide log output?

Thanks.
-Øyvind

[Adeel]

Hi Oyvind,

Yes, I am using PSM in my application.

I will keep this ticket on hold and provide you with the log output once I face the same issue again, as I do not have the log output as of now. 

Regards,

Adeel.

[Øyvind]

Thank you, Adeel. Awaiting your respons.

[Sebastiaan Merckx]

Are all 5 connected to the same mobile operator network?
When the issue occurs, can you try to ping or do a HTTP GET of e.g. google.com?

I've heard that some mobile operators force devices of the network after a certain time, to get rid of ghosts. So it would be good to check if you are actually still connected to the network. It would be good to try a lte_lc_offline() followed by a new lte_lc_connect(), when the issue occurs.

[Adeel]

Hi,

I have noticed that this happens due to the SIM provider. I logged into my sim data log and saw the events that take place. I normally see that the issue occurs when it says : PDP Context deleted.

Normally it does this every day but again gets activated. But sometimes, the PDP context is deleted but not activated and I think that leads to this error. I am not sure if this could be resolved in code as this looks like the Sim provider issue in connecting to the cell tower.

Regards,

Adeel.