connection lost after 3-4 hours

[krnelpanic]

Hi, I am having problems with RTDB. I reboot my ESP32 and everything works perfectly for 3-4 hours and then it loses connection and no longer recovers until I reboot the board. This code has been working fine for about 9 months, maybe something has changed in Firebase that generates this problem. The failure occurred about 2 weeks ago.
I am monitoring the available memory and it is always over 40000, when it doesn't recover it stays at 80000.
I have also implemented a code to upload sensors to Ubidots and it continues to work without problem.

Every 6 seconds I have these token failures:
Token info: type = id token (GITKit token), status = on refreshing
Token info: type = id token (GITKit token), status = error
Token error: code: -4, message: connection lost

[mobizt]

Your device free memory is not enough, and it's not related to the library update.

Only 80k is not enough for SSL client in the library to work, it required at least 100k - 120k.

You can set the debug port in Arduino IDE to see the error about SSL.

If you are using latest ESP32 core v2.0.11, please use v2.0.9 instead because of free heap is 30% reduced in latest core.

[krnelpanic]

Thanks for your quick response and your work
I have changed to core v2.0.9 and now I have 77000 where before it was 40000
Do you think using the new ESP32S3 N16R8 will solve the memory problems?

[mobizt]

With ESP32S3, you will gain approx. 20k from ESP32 which not affected by core version.

This library used WiFiClientSecure for SSL Client used internally and it consumed approx. 35k to 50k by SSL engine (mbedTLS) during connecting to server.

To reduce memory usage, you can use external SSL Client that uses lower memory.

I recommend you follow this post which the memory requirement can be adjusted from 512 - 16384 (16k) via ESP_SSLClient which much less than consumed by WiFiClientSecure in ESP32.

In the next version update, I will replace WiFiClientSecure that used mbedTLS with ESP_SSLClient which allow us to use more FirebaseData objects with less memory restriction because of more free memory.

No external SSL Client is required for all networking devices (Ethernet, WiFi, and GSM modules) in the next version.

This also extends more devices and platforms support.