Re: Finding Usable Nodes in our Cluster

[jwkrahn]

my $ganglia=`ganglia proc_run`;
my @results=split(/\n/, $ganglia);
foreach(@results)
{
    push @open, $_ if $_=~m/\s{1,}1\s{1,}$/;
    unshift @open, $_ if $_=~m/\s{1,}0\s{1,}$/;
}

That could be simplified to:

foreach ( `ganglia proc_run` )
{
    push    @open, $_ if /\s1\s+$/;
    unshift @open, $_ if /\s0\s+$/;
}

[Andrew_Levenson]

Awesome, it works great! I updated it to include some formatting of the output to make everything pretty.


#!/usr/bin/perl
#Andrew Levenson
#2:13PM EST
#Thursday, April 10th, 2008

#Displays nodes on Deli with 0 or 1 used processors

use strict;
use warnings;
print "\n";
my @open=("\n", "One Active Processor:\n\n");
foreach ( `ganglia proc_run` )
{
    unshift @open, $_ if /\s0\s+$/;
    push    @open, $_ if /\s1\s+$/;
}
print "Zero Active Processors:\n\n";
print $_ foreach(@open);
print "\n";

[jwkrahn]

print $_ foreach(@open);

You don't really need the loop there:

print @open;

And it might be better if you used strings instead of arrays:

use strict;
use warnings;

my $zero = "\nZero Active Processors:\n\n";
my $one  = "\nOne Active Processor:\n\n";

foreach ( `ganglia proc_run` )
{
    $zero .= $_ if /\s0\s+$/;
    $one  .= $_ if /\s1\s+$/;
}

print "$zero$one\n";

[Andrew_Levenson]

Wow, that's fantastic. I hadn't even considered that approach. It's nice because the formatting of the output of `ganglia proc_run` is conducive to being easily read with minimal reformatting effort.

Is there any considerable speed advantage to using the string instead of the array? Or does it have to do with memory usage?
Current form:


#!/usr/bin/perl
#Andrew Levenson
#4:14PM EST
#Friday, April 11th, 2008

#Displays nodes on Deli with 0 or 1 used processors

use strict;
use warnings;

my $zero = "\nZero Active Processors:\n\n";
my $one  = "\nOne Active Processor:\n\n";

foreach ( `ganglia proc_run` )
{
    $zero .= $_ if /\s0\s+$/ & !/deli/;
    $one  .= $_ if /\s1\s+$/ & !/deli/;
}

print "$zero$one\n";

[Andrew_Levenson]

Ah, thank you! I'll give it a shot when I get back to the lab.