How do I solve outbox: outbox_enqueue(53): Memory exhausted issue ? (IDFGH-14481)

[Vaibhav0216]

I am storing large data in the sd card sending this data through the mqtt to cloud. But I am facing the below issue.

I (85763) example: Available heap before allocation: 7880
I (85763) example: After allocation, Free Heap: 5572
I (85773) TAG: Processing file: /sdcard/data_tel_1737459639000.json, Size: 2285, Heap: 5572
File Size : 4116 bytes
E (85983) outbox: outbox_enqueue(53): Memory exhausted
I (85993) MQTT: Outbox size: 80006
E (85993) MQTT: Failed to enqueue telemetry data: -1
I (86003) example: After freeing, Free Heap: 7880

At starting heap size is very large almost 90k I am clearing the object string allocated by malloc ( dynamically ) how can I control on heap size increasing ?

How can I resolve this error?

[euripedesrocha]

@Vaibhav0216 the issue here is that you don't have enough memory to proceed with publishing the message.

The solution will depend on your system, I'm considering that you don't intend to switch to a module with external RAM.
Given the size of messages your system at some point might always reach this scenario. These are my suggestions:

• Enable outbox size limit to detect the issue as soon as possible.
• Set CONFIG_MQTT_OUTBOX_EXPIRED_TIMEOUT_MS to adjust the message to be deleted sooner in case of not completing the publishing on time.
• You might consider CONFIG_MQTT_REPORT_DELETED_MESSAGES to track the message deletion.

In summary, the solution is to control the message publishing process more closely and retry it when the memory is available.

I can give you more suggestions if you provide more information about your system.