Nagios – Web-Based Server Monitoring Software

By Christopher Pace

Is your Linux server down?

This one question has the power to keep us all up at night. Linux servers host your websites, handle your email, and manage your network. Your Linux server is the heart and soul of an online presence, since your databases and web applications all run on top of your server. Put simply, if your server is down, so is your business. Downtime means lost sales, and lost customers (present and future revenue). If you can’t afford downtime, you need a good server monitoring program. One such software solution is called Nagios, and it’s quite powerful.

Although Nagios isn’t the easiest web-based software solution to install (most of the server configuration is done by editing configuration files), it is extremely easy to use, once configured. Nagios presents you with a web-based status screen, which allows you to quickly view the status of all of the servers that you are monitoring. Nagios isn’t for just Linux servers either, Windows servers can be added to monitor as well. Once you are logged into Nagios, you can view the detailed status for all of the monitored servers by clicking on the “Service Detail” link.

From here, you can view the detailed information about when Nagios last checked the status of a service running on your server, and view the results of that last check. Pretty boring stuff so far, since nothing is broken. Let’s break the POP3 service on our server, and see how Nagios reacts. Within one minute, Nagios has flagged the POP3 service as being in a “critical” state. Nagios requires four failed connection attempts (by default), before an alert is issued. This is important, since sometimes a request is dropped by a router in between Nagios and the destination server. The Internet is a crazy place, and sometimes traffic isn’t delivered to it’s destination in time. Therefore, Nagios will wait for four consecutive failures, before it issues an alert.

Once Nagios has failed to connect to the server four consecutive times, the server is then placed into an alert status. From here, depending on your Nagios configuration, an email can be sent, a text message sent, or even a sound played through speakers connected to your Linux server.

Once we have successfully fixed the issue with the POP3 daemon on our Linux server, Nagios will remove the critical warning on the server, and place the server into an “OK” state. Once the monitored server’s status is changed to “OK”, emails and SMS text messages are once again sent, to inform everyone that the monitored server is fixed.

In addition, the host status on Nagios is now displayed as “OK” on the service status page.

In addition to monitoring, Nagios also supports the ability to create logs and uptime graphs which display host uptime and service stability in an easy to read format. Host state breakdown reports allow you to easily view and export server and service uptime reports.

In addition, you can also schedule downtime with Nagios, so that alerts aren’t issued when a service or server is taken down for routine maintenance. The downtime window is completely custom, and Nagios gives a summary of all planned downtime, by clicking on “Downtime”, on the navigational bar.

In the end, Nagios has the potential to save you both time and money. With Nagios, you won’t have to worry about whether or not your server is working- Nagios will let you know as soon as your server is unavailable.

Christopher Pace is a linux consultant who offers a variety of linux consulting services to clients. Linux administration services are offered remotely, which helps his clients save both money and time!

Android Application Developer – A Whole New World of Possibilities

By Kim Dsoza

Google’s Android operating system has taken the world of mobile application development by storm, for quite some time now. Granted, there are still less number of apps available for the platform compared to the other platforms like iPhone, Blackberry and Symbian but this is for sure that Google’s Android has already started spreading its tendrils to other handsets. On its recent earnings call, T-Mobile announced that it has sold its one millionth G1 phone based on the Android open-source operating system, meaning it took Google just six months to do this. This by all means is an impressive feat considering the incredible anticipation and fervor for the iPhone.

Android apps cost a good amount each, and hence can be used to rake in a steady stream of income over time. Here are the advantages that I foresee for building an Android application vis a vis other platforms:

1. Android OS Roils SmartPhone Market: Android Mobile Operating system was introduced a year back and could hardly give a competition to Apple iPhone but with the recent slew of new Android based devices the growth has been phenomenal with a phenomenal 15 point jump in just 3 months.

2. Huge developer community support: The Android platform is open to all, and as such there is a dedicated community of developers actively working on this platform. If there are any troubles that the developers run into during the development phase, there will always be help at hand. Besides, if there are any bugs, community members will also offer help during testing phase. This will make sure that your apps are stable and bug free when those are released.

3. Ease of Development and Porting: By default, Android is configured to auto-scale everything in most cases, however if layouts are specified with exact pixel values rather than the other suggested options the developers can easily make the necessary changes with the help of published content. The support for porting legacy applications to add support for larger or smaller screens is rather much simpler in case of Android. Sometimes it might be as simple as adding the following into their AndroidManifest.xml

4. Stable platform: Owing to its Linux core, the Android operating system from Google exhibits rock solid stability and resists crashes. As such, the apps developed on this platform exhibit the same characteristic, resulting in rock solid stability, resistance to anomalies in the system.

5. Many sales options: The Android apps can be sold in a variety of ways. There is the Android App Market, which the majority of users access in order to purchase and download Android apps. Secondly, there are third party stores that just about anyone can use to sell their apps. Even you can set up your own store to sell the apps, which is a huge plus, considering many other popular platforms force you to sell apps from their stores only.

6. Excellent ROI: The Android apps cost quite a good amount to download; hence you can be assured of getting excellent returns over your investment. All you have to do is find a good Android application developer for getting your apps built, and upload it in a store that is offering good commissions over sales.

As Android’s growth continues to explode since the release of the Droid, one developer, in fact, wrote that his app, which was showing modest, double-digit daily sales late last year, now reports that his app is making $13,000 a month.

But in order to net a steady stream of income it is important to partner with a well reputed organization with an established record of delivering robust mobile applications and someone who can contribute not just from technology perspective but also add value by engaging in providing suggestions for future enhancements of the product.

For starters, check out Techendeavour.com. Endeavour Software Technologies is an expert in mobile technology and advises startups, SMBs and enterprises in defining the right mobile application, selecting appropriate technologies, wireless carriers’ relationship, and establish innovative roadmap for the continuous success as the future technologies changes over time. Can be reached at info@techendeavour.com

For more information relating to android application developer visit http://www.techendeavour.com

Basic Advantages of Linux Web Hosting

By Tina Hope

Linux web hosting not only helps you build your website from a small business to a large enterprise but also gives you many advantages over contemporaries and competitors alike. Once you decide your budget and also your required features, then you will be able to decide on the Linux web hosting package that will further improve your chances of doing well in business. The scripting language that is incorporated in your website also comes into play and so does the interactive facilities that are implemented in it. There are many advantages that one ends up getting through Linux web hosting services. Some of them are mentioned below:

1. Linux is open source code software and eventually does not require the gigantic licensing fee that one usually ends up paying for others. Other operating systems command a huge licensing fee in comparison to this one and it is this virtue of minimizing costs that makes this form of web hosting highly endearing to hire. You not only get to download it free of cost but also are rendered the advantage of using it sans any sort of costs.

2. The Linux based website can be converted to a window based website at any time of the day without any hassles. The website can easily be changed back into its original form or to any other form when the requirement of the user keeps growing continuously. The conversions can be done depending on the user requirements and can also be changed according to changing times.

3. This form of hosting is the most economical form of hosting and the user gets to save a huge amount of money out of the total budget. The only costs involved are those of the distribution that are further incurred by the proprietor or the owner.

4. Linux also proves to be the most cost effective and frugal option for your website when the scripting has to be done in languages like PHP and My SQL along with Perl. Unless and until the scripting is very heavily loaded, one does not have to worry about the whole process.

5. The operating system allows the user to run as many kinds of databases one feels like running. The most widely used databases include the likes of My SQL and Postgre SQL. These databases might look interrelated by nature and also allow highly optimized communication. This is done to quickly reclaim all the data.

6. It offers paramount security. The end user does not have to worry about the security of any of the applications and can go about doing anything on the server. Designers and programmers prefer this form over any other form and can mostly be seen using it.

These advantages this form of hosting a lot of advantages that are too good to ignore and subsequently have created a huge fan base for Linux web hosting India. Be it any IT professional who deals with this, Linux hosting is never short of springing in surprises and always manages to fox people.

IDS Web Hosting a brand name in India for its web hosting services which provides best e-commerce hosting services, hosting with crystal report and domain name registration at affordable prices. For more details visit our Web hosting India website.

Motorola QUENCH – New Tricks From an Old Dog

By Simon Drew

Motorola, the world’s third largest mobile phone maker after Nokia and Samsung has unveiled its latest Android smartphones at the recently concluded 2010 Mobile World Congress held in Barcelona.

The Motorola QUENCH with MOTOBLUR is its 8th Android sporting the older 1.5 Cupcake version just when many new unveiled Androids have started using the new 2.1 Éclair. But this just confirms our suspicion that because of its open source nature, Android versions, unless severely handicapped, can easily be tweaked to rival even the latest versions coming from Google.

It also further buttresses the observation that no upgrade paths are necessary. Versions remain as OS variants with UIs like Sense form HTC and UX from Sony Ericsson making an upgrade irrelevant. The suspicion is finally confirmed when Acer came out with the latest Liquid e showing nothing else but the new 2.1 Éclair OS when they could have just provided an OS upgrade to the older Liquid. Apparently, no upgrade path exists from 1.6 to 2.1.

New Features

Despite an old OS, the QUENCH can carry itself proud among the new smartphones running the new 2.1 Éclair, thanks to the Motorola innovations built into the 1.5 Cupcake. It starts with MOTOBLUR which Motorola calls as its content delivery system that promises a unique Android experience.

It syncs your phonebook contacts, media content and communications trail in MySpace, Facebook, Twitter, Gmail and email accounts automatically on the home screen. Then there’s SWYPE, an entirely new method for text input form the same people who invented T9 predictive text. You only need a finger to swipe or trace the letters across a QWERTY keyboard on the touchscreen and the word gets spelled.

Its entertainment features also gets an innovative boost in media players that allow you to play while getting connected online to download new media content like Tune Wiki, SoundHound, GoTV and YouTube.

There’s even FM stereo streaming. The Motorola QUENCH enhances its telephony experience with noise cancellation technology and dual microphones for crystal clear voice calls. You can also benefit from its voice activated search facility that can launch Google Web search.

Apart form these, it’s your 3G phone with WiFi, HSDAP/HSUPA. You get a 3.1-inch QVGA capacitive touchscreen with 64k colors, accelerometer and proximity sensors. There’s a 5 megapixel autofocus camera with LED flash, geo tagging and CIF video recording at 25fps.

Other features include stereo FM with RDS, Bluetooth A2DP, 3.5m headphone jack and speakerphones. There’s 512 MB ROM and 256 MB RAM with 32 GB of microSD expandability.

Conclusion

To a large extent, the various Android versions whether old or new remind us of the many Linux flavours for the PC which created a fragmented market that essentially brought the Linux to fail in the home PC markets.

The QUENCH clearly shows you don’t need a new OS to compete and even edge out the competition using the new Éclair. Thanks to the Open Source nature of Android. But like Linux, it is creating a fragment markets this early and could end the same way.

For the sake of Android markets, we hope Google can get its act right and get a grip of its open source OS. As it is, with all the many OS variants and UI ported by different makers, a single upgrade to the latest 2.1 Éclair from Google, if and when that happens, would simply wipe out all the cool UIs ported into various smartphones. So you can kiss your HTC Sense or Sony Ericsson UX goodbye in one upgrade.

To find out more about the Motorola Quench you can visit best-mobile-contracts.co.uk. You can find more reviews for the Quench as well as a comparison of the best deals available.

Website Content Management Software

By David T Webb

What is Drupal?

Drupal is an open-source content management system (CMS). Basically its an environment that allows you to develop powerful websites quickly and with relative ease.

Why use Drupal?

Firstly, it’s free. It manages your website content. Easily store and edit all your content and data, display your website pages, easily and instantly edit the appearance of your website using Themes (templates), Color profiles. Drupal lets you easily add features to your website, such as Image galleries, Blogs, Forums, Calendars, Video Streaming, Podcasts, and many other features. Drupal has a large online community, supporting each other and developing drupal add-on modules to provide extra functionality to the system. Get started now with drupal at drupal.org

How Drupal works

All content; such as articles, information, user details, etc, are stored in a database. The database is accessed and managed via a database server. The design and layout of a drupal site is handled by themes. These are template files, styled with graphics and text. Themes allow you to easily change the appearance of your website without modifying any of your content. Drupal uses the PHP programming language. PHP is open-source and therefore free to use.

Drupal requires 3 things to work; A server environment, such as Apache, A PHP Server and a mySQL database server.All of the above can be downloaded in a complete package for you to use while developing websites on your PC. I recommend that Windows users check out Xampp, Linux users can use Lamp. But there are many other all-in-one PHP-mySQL development environments too. Once you have your development environment set up, then you can install drupal and start making websites.

How to install and setup Drupal

Required Software; Development environment: Xampp (Windows), Lamp (Linux), Drupal installation file (compressed archive, e.g..zip or.gz). Download from drupal.org.

Installation steps:

Extract the drupal installation file to your htdocs folder. This is the folder where your website files for your development environment are found. I will assume from here on that you extracted the drupal installation archive to a folder called ‘drupal’. (The default folder is something like ‘drupal-6.13′ with the version included.) Copy the settings.default.php in the ‘sites/default’ folder to settings.php. To do this, in your file browser, navigate to drupal, sites, default, make a copy of settings.default.php, rename the copy to settings.php. Create a database for your drupal installation to use, this may vary depending on your development environment and database server. If you are using Xampp, navigate to localhost/phpmyadmin. In the Create new database field, enter the name of your new database, e.g. drupaldb and click create. Finally, navigate to ‘localhost/drupal/install.php’ in your web browser. Follow the instructions to complete the installation of drupal.

How Drupal Themes Work

Drupal displays and styles your content using themes. A theme consists of; theme template files and theme functions. Theme template files display your content through an html and css styled template file. So your site design and content are separate. This means that you can easily change the visual display of your site without affecting the content.

How to change the theme in drupal

In drupal there are two themes that can be applied to your website; the default Theme and administration Theme. The administration theme is applied to the site when the administrator is logged in and is viewing pages under the Administer menu item. In all other cases the default theme is applied to the website. To change the default theme, navigate to Administer, Site Building, Themes. Scroll down to the theme you want, enable it by checking the checkbox. Activate it by selecting the radio button (column labeled as default). Scroll down and click Save configuration. To change the administration theme, navigate to Administer, Site Configuration, Administration theme. Select the name of the theme you want to use as the administration theme. Click Save configuration.

Conclusion

Drupal is a robust, free, community developed open source, multi-functional website creation and management system. It is arguably the best content management system available, under continuous development and improvement. It has detailed documentation on every aspect, from basic to advanced level. To get started with drupal or for more information, visit drupal.org.

David is a CMS expert who specialises in drupal websites and web development. Visit his Drupal Theme Tester to see drupal themes live in action.

The Linux Box in My Pocket

By John Dembowski

My wife and I picked up new ‘phones’ last week. Penny wanted a phone with a slide out keyboard so she would be able to text more easily. I wanted a Droid.

The Droid is a 4 inch machine running a slim Linux Kernel called Android. The whole thing is orchestrated by Google. The machine comes with 16 gigs of flash memory, a 5 megapixel camera, audio player that plays several different formats of music including MP3s, GPS, 3.7 inch touch screen, slide out keyboard, WiFi, wireless broadband, a very sophisticated (free) software installation framework, and, oh yeah, a phone.

Not wanting to scare her off I dumbed it down a tad. I said something like “This one has a keyboard. And you can log into Pandora and stream your channel 24 hours a day.” She was sold.

When were just about done checking out and I’ve had about 1/2 hour to tell her all about ‘this and that’ I mention that it doesn’t come with a manual. You have to learn how to use it by actually using it. Among other things there is a big search box on the main screen. Instinctively you find your way to Google. Google can answer any question.

We each found cool stuff to show each other over the next 8 hours. ‘TV time’ that night became ‘install-try-uninstall time’. We tried out every free Droid app we could get out hands on.

My current app list includes:

* a dictionary

* an app with information on every country

* another with info on each of the United States

* an app with just about every math and physics formula you can imagine

* a copy of the Constitution

* the periodic table with all the basics on each element

* an interface to play audio versions of just about every influential book that has fallen out of copyright

* a crappy DirecTV app to set my DVR to record (better than nothing but this is weak and I expect something really slick and similar to the same searches that can be done directly on the DirecTV box)

* an LED scroller that shows the message you type in (think “Get me a beer, plz” on a lit up sign)

* a light saber with the sound-FX following the Droid’s movement

* the Bible

* the Quran

* several WiFi tools to not only find hot spots but to see which channels have the least traffic

* a ton of relaxation noise machines

* a Darth Vader soundboard

* headlines from NPR and BBC World

* the weather radar for where I happen to be standing (goooo GPS)

* the 10 day and hour by hour forecast from the Weather Channel for where I happen to be standing (GPS is so abused in Android apps)

* a few tools to automate common Android tasks

* a guitar tuner

* flashlight app that turns the flash on and leaves it on until you turn it off

* copied 5 gigs of music to it – turning it into a USB drive for a desktop computer was a tad strange

I’ve spent probably 72 hours during the past week geeking:

* set up all the various options to my preferred settings

* set up the phone to teach me Spanish using 5 different apps

* set up a rather complex Personal Assistant to remind me of just about everything using 4 apps but I’m adding at least 2 more for specific task lists

* on my regular PC I installed the developer’s tool kit, the java programming libraries, an Android OS emulator, wrote and ran a little BS app so I could see what the developers see

* joined a couple Droid-Fanboy forums

* joined a couple Android-Developer forums

* wormed my way out of xWindows and into the underlying file structure

* tricked the phone into doing a full install of the Perl programming language

I can really see a future for the Android OS. I have no idea what is going on for iPhones and BlackBerry. They will not be able to go where the Android will go unless they are willing to let other people use their OS.

Dude, I’ve totally gone Google.

Originally posted @ the personal blog of John Dembowski