my $dbh_m= DBI->connect("dbi:mysql:XXX","root","XXX","mysql_auto_reconnect=1")

my $dbh;
{
    local $@;
    do {
        eval {
            $dbh = DBI->connect("dbi:mysql:XXX", "root", "XXX", { mysql_auto_reconnect => 1 })
        };
        if ( $@ ) {
            warn "Error: $DBI::errstrn";
            warn "Trying to reconnect in 5 sec.n";
            sleep 5;
        }
    } while ($@);
}

DBI->connect("dbi:mysql:XXX", "root", "XXX", { mysql_auto_reconnect => 1 })