The NetScaler GUI and CLI are sluggish, unresponsive, and virtually unusable on the Primary node. Further in ns.log, you will see logs similar to below:
Nov 30 01:02:00 <kern.crit> ns1 kernel: maxproc limit exceeded by uid 65532 (perl), please see tuning(7) and login.conf(5).
Nov 30 01:02:01 <kern.crit> ns1 kernel: maxproc limit exceeded by uid 65532 (nsumond), please see tuning(7) and login.conf(5).

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Do not use CURL or spawn any process from within the Perl script. Instead use Perl's built-in capabilities to query a server or accomplish what you need. Here is an example for a Server SOAP Request:

#!/usr/local/bin/perl
use strict;
use Netscaler::KAS;
use LWP::UserAgent;
use HTTP::Request;

sub myprobe 
{
	my $responsestring = "Windows";
	my $host = $_[0];
	my $port = $_[1];
	my $message = "<soapenv:Envelope xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:v1=\"http://YoursoapURL\"> 
				   <soapenv:Header/> <soapenv:Body/>
				   </soapenv:Envelope>";
	my $userAgent = LWP::UserAgent->new();
	my $request = HTTP::Request->new(POST => "http://$host:$port/");
	$request->header(SOAPAction => "http://YourSOAPActionURL/and/path");
	$request->content($message);
	$request->content_type("text/xml; charset=utf-8");
	my $response = $userAgent->request($request);
	if($response->code == 200)
	{
		if(index($response->as_string, $responsestring) != -1)
		{
			return 0;
		}
	}
	return 1;
}
probe(\&myprobe);

 

---

Problem Cause

This issue is caused by a Fork Bomb. In this example, it's due to the use of CURL in a User Monitor Perl script. The NetScaler nsumond process executes the Perl script, which executes CURL, and this repeats every time the monitor is triggered, hitting the system's MaxProc limit.

Here is an example of code that can cause this Fork Bomb to occur:

#!/usr/local/bin/perl
use strict;
use Netscaler::KAS;
sub myprobe 
{
	my $host = $_[0];
	my $port = $_[1];
	my $curl = `curl http://$host:$port/`;
	if ($curl =~ "Windows") 
	{
		return 0;
	}
	return 1;
}
probe(\&myprobe);