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Nagios: System and Network Monitoring Book

Nagios is a popular open source computer system and network monitoring application software. You can easily monitor all your hosts, network equipment and services. It can send alert when things go wrong and again when they get better.

The convenience and reliability that monitoring programs offer system administrators is astounding. Whether at home, commuting, or on vacation, admins can continuously monitor their networks, learning of issues long before they become catastrophes.

Nagios, the most popular open source solution for system and network monitoring, is extremely robust, but it's also intensely complex. This eagerly anticipated revision of the highly acclaimed Nagios: System and Network Monitoring, has been updated to address Nagios 3.0 and will help readers take full advantage of the many powerful features of the new version. Ethan Galstad, the main developer of Nagios, called the first edition of Nagios "incredibly detailed." He went on to say, "I don't think I could have gone into that much detail if I wrote a book myself."

Nagios, which runs on Linux and most *nix variants, can be configured to continuously monitor network services such as SMTP, POP3, HTTP, NNTP, SSH, and FTP. It can also supervise host resources (processor load, disk and memory usage, running processes, log files, and so on) and environmental factors, such as temperature and humidity. Readers of Nagios learn how to:

  • Install and configure the Nagios core, all standard plugins, and selected third-party plugins
  • Configure the notification system
  • Program event handlers to take automatic action when trouble occurs
  • Write Perl plugins to customize Nagios for unique system needs
  • Quickly understand Nagios data using graphing and visualization tools
  • Monitor Windows servers, SAP systems, and databases

This dense, all-inclusive guide to Nagios also contains a chapter that highlights the differences between Nagios versions 2 and 3 and gives practical migration and compatibility tips. Nagios, 2nd Edition is a key resource for any system and network administrator and will ease the pain of network monitoring migraines in no time.

Wolfgang Barth has written several books for professional network administrators, including The Firewall Book (Suse Press), Network Analysis (Suse Press), and Backup Solutions with Linux (Open Source Press). He is a professional system administrator with considerable experience using Nagios.

Book Info

  • Title: Nagios: System and Network Monitoring, 2nd Edition
  • Author: Wolfgang Barth
  • Pub Date: October 2008, 720 pp
  • ISBN 9781593271794, $59.95 USD
  • Download free chapter 18: "NagVis" (PDF)
  • Order info: order@oreilly.com // 1-800-998-9938 // 1-707-827-7000
  • Support nixCraft: Order Nagios: System and Network Monitoring from Amazon.

Power Off Server Once In a While?

From my mailbag:

I turn off the PC at home or the office once in a while. Now, I've server at colocation center. Do we need to run server 24/7? I do reboot the server once a month. Is it advisable to completely power off a server once in a while instead of 24/7 running?

[click to continue…]

MySQL vs PostgreSQL

WikiVS has published detailed comparison between MySQL and PostgreSQL. From the pages:

MySQL vs PostgreSQL is a decision many must make when approaching open-source relational databases management systems. Both are time-proven solutions that compete strongly with propriety database software. MySQL has long been assumed to be the faster but featureless of the two database systems, while PostgreSQL was assumed to be a more densely featured database system often described as an open-source version of Oracle. MySQL has been popular among various software projects because of its speed and ease of use, while PostgreSQL has had a close following from developers who come from an Oracle or SQL Server background.

=> MySQL vs PostgreSQL from the open comparison website.

Learn from Google how to save electricity while serving millions of request across a globe. Google come up with 5-step approach to build efficient data centers. From the page:

Google's mission is to organize the world's information and make it universally accessible and useful. Hundreds of millions of users access our services through the web, and supporting this traffic requires lots of computers. We strive to offer great internet services while taking our energy use very seriously. That's why, almost a decade ago, we started our efforts to make our computing infrastructure as sustainable as possible. Today we are operating what we believe to be the world's most efficient data centers.

As a result, the energy used per Google search is minimal. In the time it takes to do a Google search, your own personal computer will use more energy than we will use to answer your query.

=> Commitment to Sustainable Computing

This is an user contributed article.

PuTTY is a terminal emulator application which can act as a client for the SSH, Telnet, rlogin, and raw TCP computing protocols. You can use putty for remote login or to control your router connected via serial devices.

By default PuTTY stores the session information in the registry on Windows machine. If you have several PuTTY sessions stored in one laptop and would like to transfer those sessions to another laptop, you need to transfer HKEY_CURRENT_USER\Software\SimonTatham registry key and value as explained below:

Export the PuTTY registry key on source windows machine

Click on Start -> Run -> and enter the following regedit command in the run dialog box, which will place the PuTTY registry key and value on your desktop in the putty-registry.reg file. Please note that the name of the registry key (Simon Thatham) is the author of PuTTY.

regedit /e "%userprofile%\desktop\putty-registry.reg" HKEY_CURRENT_USER\Software\Simontatham

You can also launch the registry and interactively export the registry key value as shown below. Click on Start -> Run -> regedit -> Click File menu -> Click Export menu-item -> Enter HKEY_CURRENT_USER\Software\Simontatham in the "Selected branch" -> Save the putty-registry.reg to your desktop.

Import the PuTTY registry key on destination windows machine

Transfer the putty-registry.reg to the destination Windows machine. Right click on the .reg file and select Merge as shown below. This will display a confirmation message: Are you sure you want to add the information in putty-registry.reg to registry?. Click on 'Yes' to accept this message.

Launch the putty to verify the new sessions are transferred successfully. The registry key merge will not delete the previous PuTTY sessions. Instead, it will merge the entries to the existing PuTTY sessions on the destination windows machine.

You can also import the registry key and value interactively: Click on Start -> Run -> regedit -> Click File menu -> Click Import menu-item ->select the putty-registry.reg -> click on Import, to import the PuTTY sessions to the destination windows machine.

Turbocharge PuTTY with 12 Powerful Add-Ons explains about some modified versions of the PuTTY that stores the session information in a file instead of Windows registry.

Midori OS: Microsoft Sees End of Windows Era

Midori operating system is the code name for a microkernel-based operating system written as managed code, being developed at Microsoft, mooted as a possible successor to Microsoft Windows by many.

Midori will use the Internet to operate and data will be stored on central Microsoft server. It will remove the role of a single PC. From the BBC article:

Microsoft has kicked off a research project to create software that will take over when it retires Windows. Called Midori, the cut-down operating system is radically different to Microsoft's older programs. It is centred on the internet and does away with the dependencies that tie Windows to a single PC. It is seen as Microsoft's answer to rivals' use of "virtualisation" as a way to solve many of the problems of modern-day computing.

I don't know about Windows user, but Linux will be there as a desktop operating system along with other alternatives. I'm not going to store my data on 3rd company corporate network, I don't trust 3rd party for my data, period. Imagine security related problems. That's why, I don't use any of the Web 2.0 stuff including Google docs, flickr and so on.

I already wrote about verifying your own or ISP recursive resolvers using dig command under Linux and UNIX. However, most windows users don't have dig command installed. You can use nslookup command as follows (open dos prompt by visiting Start > Run > type "cmd" > Enter:
nslookup -type=txt -timeout=30 porttest.dns-oarc.net
nslookup -type=txt -timeout=30 porttest.dns-oarc.net ns1.your-isp.com
nslookup -type=txt -timeout=30 porttest.dns-oarc.net NS-SERVER-IP

You must see the word GOOD otherwise your dns is open to attack.

Check DNS Cache Poisoning Under Windows Xp / Vista / Server Edition using nslookup command

Check DNS Cache Poisoning Under Windows Xp / Vista / Server Edition using nslookup command