Victor's Blog about the Web, Security and Life

IEEE High Availability Database Workshop

victor — Sun, 13 Dec 2009 08:41:04 +0000

Today, I guided a workshop about high-availability database solutions at NDU. The workshop went for 6 straight hours (from 9:30 till 15:30) and was attended by more than 50 students from various universities in Lebanon. The workshop was organized by the NDU IEEE branch in collaboration with the Computer Science Club.

I started the workshop with a general overview of availability issues in Database solutions. Then, I moved to a more detailed description of Database Replication and Database Clustering before moving forward to the hands-on implementation that included the following:

How-to install / configure MySQL Cluster on Centos
How-to configure a database for asynchronous data replication
How-to configure a Cluster for real-time synchronous data mirroring
How-to configure load-balancing using the "balance" tool and Linux VFS (overview)

The unique thing behind this workshop was the ability to achieve a working solution that includes a Cluster Manager, 2 Cluster Nodes, 2 Cluster API nodes and a load-balancer while using only 3 server machines.

The solution architecture was simple and included the following machines:

192.168.0.1: this machine acted as the load balancer and the cluster manager. All requests to database operations in applications have to go through this machine which will, in turn, forward them to either 192.168.0.2 or 192.168.0.3.
- A slightly different solution will be to use Linux VFS to share a load-balanced IP address (e.g. 192.168.0.10) on 192.168.0.2 and 192.168.0.3. In this case, application database operations will have to go to the shared IP address (192.168.0.10)
192.168.0.2: this machine acted as a cluster node and a MySQL API node.
192.168.0.3: this machine acted as a cluster node and a MySQL API node.

The Future of Web Programming

victor — Wed, 02 Sep 2009 20:02:01 +0000

I was having an interesting discussion yesterday about web programming languages with a friend of mine during which we tackled various programming languages (PHP, Java, VB and C#) and their competitive nature for web programming. I found it very useful to place a summary (yet a detailed one) about this topic due to the interestingly arguable nature of this topic...

PHP:Past, Current and Future

I will start with PHP simply because it is still my favourite web scripting language. Back in 1998, when I first tackled PHP, many programmers that I knew used to make fun out of it (same way they used to make fun out of Search Engine Optimization back then as well ;) starting from its recursive name (PHP stands for PHP Hypertext Processor) reaching the naive (yet powerful) nature of the language back then. I always had my bet that one day PHP will have to evolve into an application development language (like Java or C# nowadays). Luckily now, I can safely say that is almost here with the presence of the ZendServer, PHP 5, Zend Framework and PHP-GTK. A good business solution nowadays can easily outbeat other applications in terms of performance, stability and speed of production simply by using the tools listed just above. Although these tools are not yet well-know at the commercial levels, they are being introduced (as far as I know) at many academic levels and will make it (in the very near future) to the commercial setting.

As far as the community is involved, I can safely say that PHP did a huge progress over the past two years. Back in 2003-2004, many programmers (and I was almost going to be one of them) moved into JSP with the J2EE being so powerful back then giving up while waiting for a mature and stable PHP framework to support them. Being stubborn, I insisted back then on sticking to PHP and worked for almost 4 months (full-time) back then to produce my first set of PHP modules to be used for Rapid Application Development (RAD) within websites. Lately, I ported my modules into CakePHP and Zend Framework whose combined power is ultimate for high-traffic websites that can serve hundreds of thousands of requests / hour peaking at thousands of concurrent requests with as low as 10% of CPU usage and 1 GB of RAM.

A very simple, yet convincing example of this are two websites that I developed: www.yellowpages.com.lb and www.al-sharq.com. For commercial confidentiality purposes, I cannot reveal numbers in here. Yet, you can visit these websites to get a glance about the dazzling power behind PHP performance when combined with Linux, MySQL, APC and the Zend Framework.

Java: The Enterprise Programming Language

I just love Java! I love its powerful architecture, community and powerful solutions. Yet, one main feature lacks Java to make it into the daily websites that people visit: low resource footprint. Java is well known for its huge resource utilization at the server level. A normal website developed in JSP will require at least 2 GB of RAM to properly cache JSP files. Performance, on the other hand, cannot be surpassed by any other web programming languate that I know about (make sure to add your comment if you know about one). The only thing is that you cannot have 50 websites sharing the same server unless you have at least 8 GB of RAM dedicated for the JSP container.

Visual Basic: Bye Bye!

VB is dying. Believe it or not, this language will not make it to the 2015 year. If you don't dump it now, Microsoft will in the few coming years (if not months) to give way for C#. Although it will still be used at the OS level, I don't see any reason why programmers will still be using it (unless they are like some of my friends who insist on using VB simply because they know VB and are too lazy to learn another language :)

C#: The Microsoft Bet!

Let us talk some facts here. Microsoft learned a lot from VB and learned a lot from J++ and learned a lot from the various applications / servers / services that were offered back in the recent past. As a result, Microsoft has put all of the experience gained into releasing an object-oriented language that is powerful (like Java), easy to learn (like VB) and with a low footprint (supposedly low) like PHP. I am not claiming in any way that I am a C# expert in here (believe I am not one) but I recently benchmarked a web application developed using C# for one of my clients during a security audit and I was surprised by the various security features that were introduced at the security level (especially exceptions) and at the performance level (the server handled 1024 concurrent requests / second for almost 2 minutes before it crashed). I must mention here that this benchmark is completely related to the way the application was written but it helped me gain a little more experience with how C# handles run-time errors and introduced me to the performance tweaks that IIS can help with if programmers get to know them. This lead me to conclude that Microsoft will be pushing forward with C# for the years to come with the hope to get back the old days of VB programming and move forward from there.

Conclusion

Let me make this conclusion short. If you want the details behind it, read the article again.

If you are new to programming and are interested in Website development, learn PHP. This is the key to go.

If you just love Microsoft, learn C#.

If you want to make it into Enterprise programming, learn Java.

Better yet, why not learn them all?

PHP-GTK: Is PHP Seeking Java and .NET Competition?

victor — Tue, 29 Apr 2008 06:48:17 +0000

Let's face it: PHP rocks when simplicity is in mind. One major ex-barrier for PHP Software development, though, was the inability to use any graphical client except the browser. Unlike Java and .NET, PHP programs were only accessible through web browsers (Mozilla Firefox, Safari, Internet Explorer, etc.) with support for XHTML. We all know that GUI production using XHTML is harder than normal drag-n-drop GUI editors like .NET and JAVA.

Nowadays, PHP-GTK is very promising to deliver GUI software applications using PHP. PHP-GTK is platform independent and uses an architecture "somehow" similar to that of the JAVA engine architecture. You write your program using PHP and the PHP-GTK plugin (installed separately for the Operating System) takes care of executing the program for you.

In this article, I will discuss some of the points that PHP must take into serious consideration before being considered eligible for the competition. I will also discuss the points of strength and current points of weakness in this domain.
What is GTK+?
GTK+ is a highly usable, feature rich toolkit for creating graphical user interfaces which boasts cross platform compatibility and an easy to use API. GTK+ it is written in C, but has bindings to many other popular programming languages such as C++, Python and C# among others. GTK+ is licensed under the GNU LGPL 2.1 allowing development of both free and proprietary software with GTK+ without any license fees or royalties. In other words, GTK+ is a windowing tookit with support for various GUI objects such as buttons, text fields, scroll bards, etc. that allow users to design GUI objects that are platform independent. GTK+ applications can work on any operating system that GTK+ has been ported to. At the current time, this includes almost all flavors of Unix/Linux, Windows and Mac OS.

What is PHP GTK?
PHP-GTK is an extension for the PHP programming language that implements language bindings for GTK+. It provides an object-oriented interface to GTK+ classes and functions and greatly simplifies writing client-side cross-platform GUI applications. PHP GTK, in other words, allows your PHP scripts to communicate with the GTK+ windowing tookit and, thus, allows PHP scripts to be executing within window objects.

PHP-GTK Advantages
Based on the above introduction, I will list below the advantages that PHP-GTK has over the competition, namely JAVA and .NET.

Large User Base: PHP is the most widely used language for web development by computer scientists worldwide due to its simplicity, portability, performance and reliability. PHP-GTK can take advantage of this characteristic by becoming the #1 choice for desktop applications.
GTK+ is Platform Independent: This characteristic allows PHP to outbeat the .NET platform. Any desktop application written in PHP-GTK can be used on any platform (Unix, Linux, Windows and MAC). JAVA is still a competitor in this sense since it is platform independent as well.
Community Support: GTK+, PHP and PHP-GTK are supported by three independent communities. This boosts the maturity level among the three technologies. In other words, working on a newer version of GTK+ will not affect the progress of a newer version of PHP or PHP-GTK. Moreover, the debate between the three communities helps achieve common standards for desktop applications through PHP-GTK and, thus, will help (on the long run) make PHP-GTK a standard tool for desktop application GUIs.
Free (as in Freedom): PHP comes with freedom at its core license. Any developer, researcher or commercial programmer can freely tweak the source code behind PHP, GTK+ or PHP-GTK to producer better results in terms of functionality, features, security, etc. This feature is partially available in JAVA (the JAVA plugin is, to the best of my knowledge, not open-source) while .NET is completely closed source.
Commercial Support: While PHP, PHP-GTK and GTK+ enjoy the support from a large open-source community, commercial support is also available from Zend. While this is a minor advantage when compared to other technologies, it is also crucial to keep PHP progress within the competitive path.
PHP Windows Support: Zend announced a while ago that Microsoft will be integrating PHP support into newer versions of Microsoft Windows Server editions. This will help PHP reach a wider audience. Previous installations of PHP over Windows Server were possible but required manual configuration and setup, configuration varied from one version of IIS to another, and workaround solutions were completely ad-hoc in nature.

PHP-GTK Disadvantages
In the list below, I will discuss some possible disadvantages that PHP-GTK must overcom to achieve a higher competitive edge along with Java and .NET.

Drag-n-Drop Editors: Microsoft Visual Studio and Java Netbeans are both very easy to use and program with. Programmers drag and drop GUI elements, modify GUI properties and attach code to events in a very easy manner. PHP and PHP-GTK on the other hand, lack an easy-to-use editor that provides similar functionality. Although newer versions of Zend Studio have an integrated Drag-n-Drop editor, the editor itself is still far from being user friendly when compared to other editors.
Automatic Updates: Programmers using PHP-GTK must manually upgrade to newer releases unlike JAVA and .NET that have automatic update monitors. Keeping the core technology up-to-date is crucial for obtaining a secure and reliable environment especially when critical fixes are released.
Artistic Edge: While a lot has been done in terms of the art behind GUI objects in GTK+, more work needs to be completed to achieve a neater, smoother and better looking GUI. Java has already taken this step with the Swing library and Microsoft already leads this path. PHP-GTK, on the other hand, is heavily based on advances in GTK+ and, thus, a push towards this path is still to occur.
Commercial Acceptance: The PHP GTK community must encourage and push commercial desktop application providers to start embracing and using PHP-GTK as the language of their choice. This will naturally occur on the long run but some attention towards this matter will help get PHP-GTK into the competition earlier.

Conclusion
In this article, I have discussed my personal point of view about PHP GTK and the promising future it has. Despite the many advantages that PHP-GTK can make use of to enter (and probably outbeat) the competition, lots of preliminary and basic work still needs to be done before commercial acceptance for PHP GTK starts occurring.

How To Play Audio Clips in Java Applications

victor — Wed, 24 Jan 2007 16:03:33 +0000

It is well-know about the ease to play audio clips in Java when dealing with applets.

It is, however, hard to get a Java application to play audio clips because there is no such interface for audio clips.

In this article, I will demonstrate how to play audio clips.
To play clips, we must use some undocumented classes in Java.

import sun.audio.*; //import the sun.audio package
import java.io.*;
// Open an input stream to the audio file.
InputStream in = new FileInputStream(Filename);
// Create an AudioStream object from the input stream.
AudioStream as = new AudioStream(in);
// Use the static class member "player" from class AudioPlayer to play
// clip.
AudioPlayer.player.start(as);
// Similarly, to stop the audio.
AudioPlayer.player.stop(as);

To use a URL as the audio stream source, substitute the following for the input stream and audio stream setup:

AudioStream as = new AudioStream (url.openStream());

Playing the audio stream continuously adds a bit more complexity:
// Create audio stream as discussed previously.
// Create AudioData source.
AudioData data = as.getData();
// Create ContinuousAudioDataStream.
ContinuousAudioDataStream cas = new ContinuousAudioDataStream (data);
// Play audio.
AudioPlayer.player.play (cas);
// Similarly, to stop the audio.
AudioPlayer.player.stop (cas);

Java Software

victor — Thu, 29 Sep 2005 09:48:03 +0000

You can download the Java SDK from the Java website by clicking here.
A Trial download of the Java SunOne studio can be downloaded from here.
The Java documentation can be downloaded from here.