It was not a good idea to work all migration of the world on the same day ....
in my case it also expired SSL certificate on 03/02/17 and i cannot renew
erro front and back
Link to database cannot be established: SQLSTATE[HY000] [2003] Can't connect to MySQL server on 'sql1.prestashopfr1.ha.ovh.net' (4)
fix soon please