bug: mariadb Got an error reading communication

 Finally: not to solve it , but we can look

1. 

https://severalnines.com/blog/common-mysql-error-got-error-reading-communication-packet/

https://www.percona.com/blog/2016/05/16/mysql-got-an-error-reading-communication-packet-errors/

2. flask + sqlmyachle

https://www.maxlist.xyz/2020/10/06/flask-sqlalchemy-parameter/

https://flask-sqlalchemy.palletsprojects.com/en/2.x/config/

3. performance

https://www.datadoghq.com/blog/monitoring-mysql-performance-metrics/

https://stackoverflow.com/questions/2214039/command-to-check-read-write-ratio