#! perl
use strict;
use warnings;
use Data::Dump;

my %nodemetrics;
my @nodelist   =  qw(server1 server2);
my @attributes =  qw(memory cpu disk network);
my $string     = '1024|2200|30|100';
my @data       =  split /\|/, $string;

@{  $nodemetrics{$_     } }{@attributes} = (0) x @attributes for @nodelist;
dd \%nodemetrics;
@{  $nodemetrics{server1} }{@attributes} = @data;
dd \%nodemetrics;