In some MySQL configurations, you may find that connections to databases continuously timeout and correspond to the following entries in the MySQL error log:
[Warning] Aborted connection to db: 'username_site' user: 'username_site' host: 'localhost' (Got timeout reading communication packets)
Timeouts reading communication packates are often caused by the incorrect wait_timeout value set in /etc/my.cnf.
In the above example, connections would timeout every 30 seconds.
Refer to the MySQL documentation for wait_timeout to ensure it's set to meet your server's needs.