This method is supplied since mysqlnd: http://php.net/manual/fr/function.mysqli-get-client-stats.php
It allows to get a lot of statistics (byte_received...)
Are these information collected at query time (while sending the sql request, maybe they are simply part of the result returned by MySQL server) or are these collected with another request call to the mysql server ?
I try to evaluate the kind of overhead I'll have by calling this stat function really frequently in our dev environment