What you want to do is create your labels only 1 time, starting with an empty string of spaces as text. Then in your update sub, fill them in with a configure. 
#!/usr/bin/perl
use strict;
use warnings;
use Tk;

my @array = ('red','green','yellow');
my @host_array = qw(server1 server2 server3 server4);

my %labs;

my $window = MainWindow->new();
$window->minsize( qw(250 250));
$window->title("Server Status");
$window->configure (-background => 'grey');

my $top = $window->Frame(-background => 'grey',)->pack(-side=>'top',-f
+ill=>'x');

foreach my $host (@host_array){
  
   $labs{$host} = $top->Label(-text=>"$host",-background => 'white')->
+pack();

  }


#$window->Button(-text => "Refresh", -command => \&pinghost )->pack;

my $timer = $window->repeat(2000,\&pinghost);

$window->Button(-text => "Quit", -command => \&Quit )->pack;

#&pinghost;

MainLoop();

#########################################################

sub pinghost{
  
   foreach my $host (@host_array) {
  
    push (@array,shift(@array));
  
    my $color = $array[0];
    my $rand = rand 1;
    
    $labs{$host}->configure(-text=>"$host-$rand", -background => "$col
+or");
  }
  #$window->update;
}

sub Quit{
  exit;
}

[download]
I'm not really a human, but I play one on earth.
Old Perl Programmer Haiku

In reply to Re: TK refresh widgit data by zentara
in thread TK refresh widgit data by siffland

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.