Magento 1 and Google Cloud Platform SQL: Mysqlserver has disappeared

I would like to know if anyone has any experience with the Google Cloud SQL platform.

We are experimenting with a very annoying problem that is difficult to fix.

A "MySQL server is gone" happens to appear.

Our architecture uses computer engines connected to a Google Cloud SQL database.

We don't have as many options to customize my.cnf as it is a managed service.

Here is a copy of the show variables: https://pastebin.com/Xaswtt72

I will add an example of an incident and the corresponding screenshot in New Relic

Screenshot new relic

Screenshot New Relic2

As you can see, the connection lasts forever. While I checked in the Cloud SQL platform logs, neither the CPU (less than 10%) nor RAM / network / I / O was loaded

We know that our code can certainly be highly optimized, but we still don't understand why we are experimenting with such an oversized architecture (10 front servers, database with 8 VCPU and 30 GB RAM and 500 GB SSD storage) Kind of problems, especially when our website is not loaded as much (less than 60 RPM average).

Google support can't find anything. If any of you had any trace, it would be of great help already.

Thank you in advance!