my %site = (
        24j1 => { count=>1, devices=>['192.168.0.1'] },
        1924 => { count=>3, devices=>['192.168.1.1','192.168.1.3','192.168.1.9'] },
        etc  => { count=>2, devices=>['192.168.2.1','192.168.2.23'] },
        ccp  => { count=>1, devices=>['192.168.3.1'] },
);

sub my_sort {
	if(  ("$a" ~~ @datacenters) && ("$b" ~~ @datacenters) )  {
		return $site{$b}->{count} <=> $site{$a}->{count};
	}
	if(  ("$a" ~~ @datacenters)  && ! ( "$b" ~~ @datacenters) ) { return $a }  # Warnings go away if I 
	if(  ("$b" ~~ @datacenters)  && ! ( "$a" ~~ @datacenters) ) { return $b }  # comment out these two lines.
	if(  ( $a  =~ $eu_regex   )  &&   (  $b  !~ $eu_regex   ) ) { return $a }
	if(  ( $b  =~ $eu_regex   )  &&   (  $a  !~ $eu_regex   ) ) { return $b }
	return $site{$b}->{count} <=> $site{$a}->{count};
}

foreach my $site ( sort my_sort keys %site  ) {do_stuff_with($site) }