Congrats on your first CPAN module!

This is more a nit than it is an operational fix, but I always prefer to see hash-based params passed in as a hash reference, as opposed to a hash:

this({ 
        string => $string,
        times => 10,
    });

sub this {
    my $p = shift; # all params in hashref
    print $p->{string} x $p->{times};
}
[download]

I find it easier to track and organize things, and if you ever want to pass in another non-hash-based parameter later on down the road, it's much simpler than having to refactor your code to suit the new arg list. I wrote about this a few years ago.

my $href = { string => "Hello, world!" };
my $previous_error = $error;

this($href, $previous_error);

sub this {
    my $p = shift; # all params in hashref
    my $prev_error = shift;

    if (not $prev_error){
        print $p->{string};
    }
}
[download]

Also, it might be worth setting some reasonable defaults instead of forcing the user to send in all parameters for every call:

this();

sub this {
    my $p = shift;

    $p->{hostname} = $p->{hostname} || "0.pool.ntp.org";
    $p->{port} = $p->{port} || 123;
}
[download]

-stevieb