[ ... ]

for my $hit ( map { $_->{'_source'} } @{ $results->{'hits'}->{'hits'} } ) {
    $interesting{ $hit->{'request'} }->{ $hit->{'clientip'} }++;
}

for my $resource ( keys %interesting ) {
    say "Resource: $resource";
    foreach my $ip ( keys %{ $interesting{ $resource } } ) {
        say "\t$ip made $interesting{ $resource }->{ $ip } requests";
    }
}