I learned recently that Wikimedia, the foundation that is making Wikipedia,  is on the road to migrate their servers to a single Linux Distribution. Until then, they are using various flavors of Linux Redhat and Fedora.

They said that this move will will allow to simplify their system administration.

Wikimedia has around 400 servers running and this is a major move for Ubuntu and will give the distribution the credibility it needs in large scale environments.

Indeed, Wikimedia server manage more than 10 Billion pageviews a month and peeks can see 50 000 hits per seconds.

Wikimedia is a rapidly growing technical environment as during their first 18 month they got for 15 server to 200.

Canonical prooves again the popularity and stability of their distribution, after releasing the first server edition in 2005.

Note that the new edition of Ubuntu (Intrepid Ibex) will be released at the end of October.

This artible was originally published on Zen-Dreams.com — Reproduction without authorization is strictly prohibited.

As I already said before, ZdStatistics version 2.0 will be out next week. It is quite operationnal and less spam is caught in the statistics as well as redirections.

This simply means that statistics are much more realistics. This new version will allow more tips and tricks for spam detection thanks to the search engine included.

As for now, I’m still evaluating the possibiility to include outgoing links into the stats for version 2 (don’t worry it will come in version 2.1 if not in V2.0).

Below are some screenshots of the new features of the plugin.

Date Selector

Calendar in every page

All pages are now displaying a date selector allowing you to choose your time span anywhere in the statistics.

Technologies tab

ZdStatistics V2 Browser View

This tab shows you what browser/OS was used to navigate your site.

Daily Stats

ZdStatistics V2 Daily Stats

New daily chart now uses Google Vizualisation charts to replace the OpenFlashChart component. This will give you more compatibility as it only needs support for javascript.

Geolocalisation

ZdStatistics V2 Geolocalisation view

The new geolocalisation tab will not only display you the list of cities that your visitors are coming from, but they will also be displayed within the page using Google Maps API (You will therefore need an API key)

This artible was originally published on Zen-Dreams.com — Reproduction without authorization is strictly prohibited.

As you will notice, I will make some updates on most of my Wordpress plugins in the coming days.

So here is the brand new version of ZdCommentsWidget. This version only includes a minor change but makes it more efficient as a Recent comment widget.

In fact I just added the possibility to have a link to the comment instead of just having a link to the author’s website. I also removed the limit on users displayed (until now only not registered users could be displayed).

You can get the latest version here : zdcommentswidget_101

This artible was originally published on Zen-Dreams.com — Reproduction without authorization is strictly prohibited.

I’ve been working a lot on ZdStatistics V2 until now, Today i’ve managed to find out how to include the media bar inside the translation editor and also how to fix the editor problem.

You will now be able to add pictures directly from the editor without having to find the correct URL.

Regarding the problem with the editor load, is due to the cforms II plugin - see this support issue.

If you need the cforms II plugin and Zdmultilang at the same time, I would advise you to deactivate the WP Editor Button support in your general settings (in the cformsII panel) as shown below :

This artible was originally published on Zen-Dreams.com — Reproduction without authorization is strictly prohibited.

I’ve been off for quite a long time on Zen-Dreams and this is mainly due to the fact that I’ve been rebuilding ZdStatistics.

ZdStatistics will be available next week in version 2.0. Why next week ? Simply because I need to test it before release, so it’s been installed on this blog and depending on the results I will get until next week I will improve it as much as I can.

Here is a list of the new features and modifications :

• Changed the flash chart to Google vizualisation so that it loads faster and can be compliant with any browser with javascript support.
• Export data to CSV files so that you can process them like you want
• Check Redirections of pages - do not log them. In fact sometimes a page was counted twice because the user specified an url without the pending / and wordpress did the redirection.
• Display tabs in the admin section optionally
• Search feature !
• Better Spam detection using an anti spam provider (default is spamhaus.org)
• Now recording hits with timezone as specified in your wordpress configuration.
• Geolocalisation is now using Google Maps to display visitors (needs a Google maps API key)
• Using a calendar to choose the time period you wish to see
• Debug option for a better support
  

This artible was originally published on Zen-Dreams.com — Reproduction without authorization is strictly prohibited.

First, before to talk about the definition of High Availability, I’d like to introduce the notion of availability. A system is considered unavailable when it becomes unusable or even usable but with too limited functions.
There are many reasons for this and some of these are commonly called Single Point of Failure (SPOF), others are most of the time due to bad operations, or Murphy’s Law

High Availability is a global concept used to make the system globally available as much as possible, i.e., with the fewest downtimes possible. Prior to think your system architecture, you must define your Service Level Agreement (SLA). The SLA is the document where you define the availability of your system, may it be planned or unplanned, but also response times, and monitoring to be performed so that preventive actions can be taken.

Availability is often expressed in percentage of the time the system must work. This percentage is calculated on a year average then re-processed in a monthly rate giving the amount of time the system can be down each month.

For example, if you want your system to be up five nine (99.999%) this means it will be up 525594.744 minutes a year. According to this calculation, you are allowed to have 5.25 minutes of service disruption each year, i.e. 44 seconds each month.

Once you decided your availability rate, you can design, or improve, your architecture. To do so, you should identify any SPOF and make it a non-SPOF component.

They can be, but not limited to, Database servers, Network components (such as load-balancer, switch, router, firewall, etc…), Application servers, Filers, Disks, Authentication servers.
Having identified those SPOF will allow you to decide the gain vs. cost of having them redundant.

Here is an example of what could be an Highly Available architecture

Management

High Availability is not only a concept for the architecture of your system, but also includes best-practices on management. This management part is as important as the architecture, because you may have the best architecture design ever, if you don’t make continuous improvement and monitoring on each element, you will never be able to do preventive actions.

As I mentioned before your SLA is here to help you define what has to be monitored, triggers on critical/non-critical events and various Key Performance Indicator (KPI) to ensure your system is going well.

Of course, the SLA is not enough to ensure availability, you have to make sure your Operation Manuals are well documented and always up-to-date, your Disaster Recovery Plan is existing, tested at least each year and also well documented, and finally, backups stored in a safe place, duplicated and always correct. Finally, have your operational teams, very well trained and available 24×7.

Remember that having your systems redundant is not sufficient; make also sure to have a great data-replication policy, even more when using RDBS to avoid data corruption on all your Database nodes.

Tools and Techniques

Some of the commonly used Tools include AIX HA-CMP, Sun Cluster, Heartbeat (Open Source), Cisco Load Balancers, EMC² filers, Network Appliance, and so on…

Some of the techniques used to make a system Highly Available are:

• Load Balancing
• Reverse Proxy
• Clustering
• Virtualization
• Failover

I will not enter into the details of each techniques and tools in this post, but stay tuned as I’ll write on these in a near future.

This artible was originally published on Zen-Dreams.com — Reproduction without authorization is strictly prohibited.

I decided to take part of the Very nice blog Contest that is currently going on at http://veryniceblog.over-blog.com/

You can leave comments for my entry here.

This artible was originally published on Zen-Dreams.com — Reproduction without authorization is strictly prohibited.

Last night, I’ve been stuck with my Ubuntu distribution as I wanted to add templates for creating new documents. The main problem is that I don’t like to have too much folders in my home directory and I couldn’t find the Templates folder. Recreating didn’t solve the problem.

Because yes, that’s where the file templates should be located.

But, I discovered this file : ~/.config/user-dirs.dirs which contains directives to tell gnome where to find some files it needs.

Therefore you can tell Gnome where it will find it’s templates, but also where it has to look for your music, vidéos, pictures and so on…

For example, you can set it like this, with /media/mydata a vfat disk shared with a Windows system (or a Filer, Samba Share, etc…) or like me, just another ext3 disk.

XDG_DESKTOP_DIR="$HOME/Desktop"
XDG_DOWNLOAD_DIR="/media/mydata/Downloads"
XDG_TEMPLATES_DIR="$HOME/.templates"
XDG_PUBLICSHARE_DIR="$HOME/"
XDG_DOCUMENTS_DIR="/media/mydata/MyDocuments"
XDG_MUSIC_DIR="/media/mydata/Music"
XDG_PICTURES_DIR="/media/mydatas/Pictures"
XDG_VIDEOS_DIR="/media/mydata/Videos"

Once you have setup your templates folder, you can go directly via the Go->Templates menu and creating files. I created these PHP Source and HTML Page

This artible was originally published on Zen-Dreams.com — Reproduction without authorization is strictly prohibited.

That’s now official, My family and I will immigrate to Canada in January 2009. We are planning to sell all our stuff before the end of the year and only bring with us the necessary material to settle down there.

All we have to do now is to look for a house for the 4 of us, and of course a Job that corresponds to my experience/competencies — you may have a look at my resume.

So far, I’ve been working as IT Manager for large companies but also as system administrator and software developper.

For now, I’m mostly looking for a job in Infrastructure management or Project Management.

If you are interested or know someone who might be, do not hesitate to pass the information / contact me.

This artible was originally published on Zen-Dreams.com — Reproduction without authorization is strictly prohibited.

As a reminder, this article is the fourth of a series called Write your own plugin for Wordpress

1. Introduction to plugins
2. Plugin’s skeletton
3. Activation, Hooks & Filters
4. Widgets Definition

1. Widgets definition

A widget is, in fact, a plugin that will allow users to display a block on their sidebar. That being said, there are only one action to use in order to create a Widget.

This action is called widgets_init - therefore you can call it like this : add_action(’widgets_init’, function_name);

Once you have done this, you will have to register two other functions inside this function_name function only if sidebars are available with your wordpress install.

Here is some code that can do the trick :

function function_name() {
	if ( !function_exists('register_sidebar_widget') || !function_exists('register_widget_control') )
		return;
	register_sidebar_widget(string $name,callback $function);
	// register_sidebar_widget takes the name of the widget and the function that will be used to display it.
	register_widget_control(string $name, callback $function2);
	// register_widget_control takes the name of the widget and the function that will be used to to change options (in the design panel).
}

That’s pretty all you need to know for Widgets. All the rest is non widget specific (options, actions and filters, api calls)

2. Sample Widget

Here below you will find a sample widget in written in fully object oriented php - not there is no option tab. This widget will only display a Simple Hello World with widget title customisable.

/*
Plugin Name: ZenDreams_Sample_Widget
Plugin URI: http://www.zen-dreams.com/
Description: Sample Widget
Version: 1.0
Author: Anthony PETITBOIS
Author URI: http://www.zen-dreams.com/
*/
class myWidget {

	function myWidget() {
		add_action('widgets_init', array(& $this, 'init_widget'));
	}

	function init_widget() {
		if ( !function_exists('register_sidebar_widget') || !function_exists('register_widget_control') )
			return;
		register_sidebar_widget(array('myWidget','widgets'),array(& $this, 'widget'));
		register_widget_control(array('myWidget', 'widgets'), array(& $this, 'widget_options'));
	}

	function widget($args) {
		global $wpdb;

		$WidgetTitle=get_option('mywidget_options');
		extract($args);

		echo $before_widget.$before_title.$WidgetTitle.$after_title;
		echo 'Hello World !';
		echo $after_widget;
	}

	function widget_options() {
		if ($_POST['mywidget_options']) {
			$option=$_POST['mywidget_options'];
			update_option('mywidget_options',$option);
		}
		$option=get_option('mywidget_options');
		echo '<label for="mywidget_options">Title : <input id="mywidget_options" name="mywidget_options" type="text" value="'.$option.'" /></label>';
	}
}
$myWidgetVariable= new myWidget ();

This artible was originally published on Zen-Dreams.com — Reproduction without authorization is strictly prohibited.