Re: capture cpu and memory usage of JVM using Perl

You should look at 'ps -aux' (the '-' is deprecated on some *nix then use 'ps aux') and its output, else if 'ps' does not give all the info you need read up on the proc filesystem.

Here is some code:

#!/usr/bin/perl
use strict;
use Data::Dumper;
use constant PROG_NAME => 10;

my $what_im_looking_for = 'JVM';
my %ps_hash;
my @ps = `ps aux`;

foreach (@ps) {
    my @tmp = split;
    next if ($tmp[PROG_NAME] ne $what_im_looking_for);
    $ps_hash{$tmp[PROG_NAME]}{cpu}  += $tmp[3];
    $ps_hash{$tmp[PROG_NAME]}{mem}  += $tmp[4];
    $ps_hash{$tmp[PROG_NAME]}{time} += $tmp[9];

}


print Dumper(\%ps_hash);
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Look at the output of 'ps aux' and find what your JVM is listed as in the proc table. Then just stick the name in $what_im_looking_for
Sample ps output:

USER       PID %CPU %MEM   VSZ  RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.1  1324   76 ?        S     2001   4:22 init [3
+]
root         2  0.0  0.0     0    0 ?        SW    2001   0:07 [kflush
+d]
root         3  0.0  0.0     0    0 ?        SW    2001   0:12 [kupdat
+e]
root         4  0.0  0.0     0    0 ?        SW    2001   0:00 [kpiod]
root         5  0.0  0.0     0    0 ?        SW    2001   0:25 [kswapd
+]
root         6  0.0  0.0     0    0 ?        SW<   2001   0:00 [mdreco
+veryd]
root        45  0.0  0.0     0    0 ?        SW    2001   0:00 [khubd]
root       353  0.0  0.5  1384  340 ?        S     2001   0:26 syslogd
+ -m 0
root       363  0.0  0.2  1680  184 ?        S     2001   0:01 klogd
                                                               ^^^^^^^
+^^^^^^^
                                                               This is
+ where the name is
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grep

grep> cd pub
grep> more beer
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Comment on Re: capture cpu and memory usage of JVM using Perl Select or Download Code

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Re: Re: capture cpu and memory usage of JVM using Perl by rob_au (Abbot) on Jan 05, 2002 at 09:14 UTC
I have described an alternate method using the Proc::Process module at Determining memory usage of a process... - This module gives access to the process table in a consistent fashion, hiding the vagarities of different `/proc` implementations. With regard to the question at hand, the following code incorporating Proc::ProcessTable may be of use: use strict; print join("\n", &usage("jvm")), "\n"; # this subroutine takes only one parameter, the process name # to return memory usage information on # # Returns array of two values, raw process memory size and # percentage memory utilisation, in this order. Returns # undefined if these values cannot be determined. sub usage { use Proc::ProcessTable; my @usage; my $proc = Proc::ProcessTable->new; my %fields = map { $_ => 1 } $proc->fields; return undef unless exists $fields{'cmnd'}; foreach (@{$proc->table}) { if ($_->cmnd =~ /$_[0]/) { my @proc; push (@proc, $_->size) if exists $fields{'size'}; push (@proc, $_->pctmem) if exists $fields{'pctmem'}; push @usage, \@proc; } } return @usage; } [download] `perl -e 's&&rob@cowsnet.com.au&&&split/[@.]/&&s&.com.&_&&&print'`	[reply] [d/l] [select]

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Re: Re: capture cpu and memory usage of JVM using Perl
by rob_au (Abbot) on Jan 05, 2002 at 09:14 UTC

Proc::Process

Determining memory usage of a process...

/proc

With regard to the question at hand, the following code incorporating Proc::ProcessTable may be of use:

use strict;

print join("\n", &usage("jvm")), "\n";

#   this subroutine takes only one parameter, the process name
#   to return memory usage information on
#
#   Returns array of two values, raw process memory size and 
#   percentage memory utilisation, in this order.  Returns 
#   undefined if these values cannot be determined.

sub usage {
    use Proc::ProcessTable;
    my @usage;
    my $proc = Proc::ProcessTable->new;
    my %fields = map { $_ => 1 } $proc->fields;
    return undef unless exists $fields{'cmnd'};
    foreach (@{$proc->table}) {
        if ($_->cmnd =~ /$_[0]/) {
            my @proc;
            push (@proc, $_->size) if exists $fields{'size'};
            push (@proc, $_->pctmem) if exists $fields{'pctmem'};
            push @usage, \@proc;
        }
    }
    return @usage;
}
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perl -e 's&&rob@cowsnet.com.au&&&split/[@.]/&&s&.com.&_&&&print'

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