>>> a far more common reason in the wild for a connection disappearing is... You are correct about the failure modes and mitigations in the general case, howev

>>> a far more common reason in the wild for a connection disappearing is... You are correct about the failure modes and mitigations in the general case, however for MySQL the most common reason by far for connections to disappear is the wait_timeout systematically being misconfigured and way too short. Databases configured to drop connections every few seconds do drop client connections all the time. No surprise.