#!/usr/bin/env perl
use 5.016;
use warnings;
use Carp::Always;

BEGIN { *CORE::GLOBAL::exit = sub { die } }
END { say "END block"; }

my $crawler = Crawler->new;
$crawler->run;

die;

package Crawler {
    use parent 'LWP::UserAgent';
    # use a bunch of other modules for the processing.

    sub new {
        my $self = $class->SUPER::new(%args);
        $self->{ids} = (1..100);  # These normally are pulled from a DB.
        return $self;
    }

    sub run {
        my $self = shift;
        my @idx = shuffle 0 .. -1 + @{ $self->{ids} };
        my $cur = 0;
        for my $i (@idx) {
            my $id = $self->{ids}[$i];
            printf "%d/%d: %s (%d)\n", ++$cur, 0+@idx, $id, $i;
            # Fetch and process stuff related to this id.
        }
    }

    sub DESTROY { say "Crawler destroyed" }
}