You're going to want to write a DBI wrapper. I have something like this in every project I work on. Something like:

package DBI_Wrapper;

sub new
{
    my $class = shift;

    my $self = bless {
        dbh => [],
        active => 0,
    }, $class;
}

sub add_dbhs
{
    my $self = shift;

    push @{$self->{dbh}}, @_;
}

sub AUTOLOAD
{
    my $meth = our $AUTOLOAD;
    (my $func = $meth) =~ s/.*:://;

    my $self = shift;

    my $start = $self->{active};
    my $dbh;
    while (1)
    {
        $dbh = $self->{dbh}->[$self->{active}];
        eval { $dbh->ping };
        last unless $@;

        $self->{active}++;
        $self->{active} %= @{$self->{dbh}};
        die "No valid DBH found\n" if $self->{active} == $start;
    }

    return $dbh->$meth( @_ );
}
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Or, something like that. :-)