Network Monitoring with Linux
NOCOL, Network Operation Center On-Line, enables a designated machine to host a collection of network monitoring agents. These agents can perform a variety of tasks, from checking that a machine is “up” using the ICMP ping method to ensuring that a remote web server is operating as it should by requesting a test page. This allows problems on a network to be diagnosed and reported in a variety of ways, be it by e-mail, web page or dedicated terminal.
The alerting system works via escalation. Normally, any data reported is classed as INFO. However, if a service starts misbehaving, it can be flagged as either WARNING, ERROR or CRITICAL. If a problem is not dealt with, it will escalate (WARNING will move up to ERROR, ERROR will move up to CRITICAL). For example, you may have a machine which has to reboot itself periodically. You would therefore expect NOCOL to complain that the machine stops responding now and then. In this situation, you would class such an event as a WARNING. You will then be kept aware when reboots occur: if the event escalates up to ERROR or beyond, you'll know something has gone seriously wrong.
Most routers and similar equipment today are SNMP (simple network monitoring protocol) compatible, and several of the NOCOL agents have the ability to interrogate such devices.
NOCOL does not need to run as root. The few binaries that do need to be privileged are set SUID root during the installation process. It is recommended that you create a user called “nocol” on your system for all NOCOL-related activities, including using it during installation.
NOCOL is available from ftp://ftp.navya.com/pub/. At the time of this writing, the latest stable version was nocol-4.2.tar.gz, which will be used for the purposes of this article.
NOCOL makes extensive use of Perl, so ensure that Perl is installed before continuing. In the unlikely event your Linux system does not already have Perl, obtain it from http://www.perl.com/CPAN/.
Once you have the NOCOL archive safely sitting on your proposed monitoring server (a 486/66DX machine with 32MB of memory sufficed for us), perform the magic:
gzip -dc nocol-4.2.tar.gz | tar xvf-
We installed NOCOL on a Red Hat 5.2 system, upgraded to allow use of the Linux 2.2.1 kernel. Enter the freshly generated nocol-4.2 directory, and then type:
./ConfigureYou will then be asked a few simple questions regarding your system:
Enter top-level directory: The NOCOL tree defaults to being located at /usr/local/nocol, but you may adjust it to suit. Make sure the “nocol” user has permission to write to any directory you specify.
Enter location of man pages: These reside under the main tree by default, but you may prefer them in the more “traditional” location on your system.
Enter extension for man pages: I stuck with the default of n for this option.
Enter FULLY QUALIFIED name of your log host: The server I set up for the main NOCOL monitors was also used for logging purposes, and this option does default to the host name of the installation machine. For simplicity, accept the default.
Where is your MAIL program located? For NOCOL's e-mail alerting system to function, it needs access to the mail binary. The default of /bin/mail should work with most Linux installations.
Where should the operational e-mail go? This e-mail address is for general NOCOL messages. Set it as appropriate.
Where should urgent/critical e-mail go? Similarly, this e-mail address is for the urgent stuff (e.g., “The web server has exploded!”).
Which compiler would you like to use? Parts of the NOCOL system have been coded in C. The default choice of cc should suffice.
Which compiler options do you want (-DDEBUG)? This is actually for developers, so accepting the default of -O will be fine.
Where is Perl located on your system? Enter the path to your Perl binary here, accepting the default of /usr/bin/perl if that is correct.
|Making Linux and Android Get Along (It's Not as Hard as It Sounds)||May 16, 2013|
|Drupal Is a Framework: Why Everyone Needs to Understand This||May 15, 2013|
|Home, My Backup Data Center||May 13, 2013|
|Non-Linux FOSS: Seashore||May 10, 2013|
|Trying to Tame the Tablet||May 08, 2013|
|Dart: a New Web Programming Experience||May 07, 2013|
- RSS Feeds
- Making Linux and Android Get Along (It's Not as Hard as It Sounds)
- New Products
- Drupal Is a Framework: Why Everyone Needs to Understand This
- A Topic for Discussion - Open Source Feature-Richness?
- Home, My Backup Data Center
- Validate an E-Mail Address with PHP, the Right Way
- Tech Tip: Really Simple HTTP Server with Python
- Readers' Choice Awards
- New Products
- git-annex assistant
5 hours 25 sec ago
- direct cable connection
5 hours 22 min ago
- Agreed on AirDroid. With my
5 hours 33 min ago
- I just learned this
5 hours 37 min ago
6 hours 7 min ago
- not living upto the mobile revolution
8 hours 58 min ago
- Deceptive Advertising and
9 hours 34 min ago
- Let\'s declare that you have
9 hours 35 min ago
- Alterations in Contest Due
9 hours 36 min ago
- At a numbers mindset, your
9 hours 37 min ago
Free Webinar: Linux Backup and Recovery
Most companies incorporate backup procedures for critical data, which can be restored quickly if a loss occurs. However, fewer companies are prepared for catastrophic system failures, in which they lose all data, the entire operating system, applications, settings, patches and more, reducing their system(s) to “bare metal.” After all, before data can be restored to a system, there must be a system to restore it to.
In this one hour webinar, learn how to enhance your existing backup strategies for better disaster recovery preparedness using Storix System Backup Administrator (SBAdmin), a highly flexible bare-metal recovery solution for UNIX and Linux systems.