Pandora an amazing DJ

Years ago, I started to listen on-line music at music yahoo.
I have to confess, at beginning, was a painful task trying to conduct the programming provided by the "Yahoo's DJ".
However, as the time past, I felt more comfortable with the music played.
Just one BIG problem, Music Yahoo only works with IExplorer and I'm a Linux user.

Ok, I can live with that, live without music in my head during my work hours. :-(
But a ride the lighting shine over my head.
I try again Pandora and now I feel happy with the music that it provides me. :-D
Sure, the beginning was awful, but it's worth.

Enjoy it.

Web 2.0 and Grid

Certainly, Web 2.0 is here, likewise, Grid computing is out there.

Today, most of the Internet users have used some Web 2.0 application, due to her interaction with some popular web sites such as: google.com, gmail.com, youtube.com, flickr.com, myspace.com, facebook.com, del.icio.us, digg.com. These sites deal with either user communication or look up information, hidding to end user its complexity operation.

Every day, more Internet users have access to more information and more powerful tools to mine the new Internet. This user is not just a consumer, instead a prosumer (producer and consumer). Then, she demands a powerful and scalable computational infrastructure to carry out the tasks, in a near future, become a daily tasks such as: determine investment targets, forecast the weather for planning your next vacation, resolve complex mathematical models for her research at chemestry class, and so on.

The goal must be: keep closing the gap between access to complex computational infrastructures and non-geek user in order to do her daily task.

Then, "ask not what internet can do for you - ask what you can do for internet", next big web application is waiting for be developed.

Screencasting in Linux

Screencasting, according to wikipedia, stand for record computer screen output, often containing a narration. Then, screencasting can be used for many different and useful purposes. In particular, people working with computer systems can share their expertise with anothers posting video-howtos about, almost, any thing to deal with computers.

Now, many open source and free applications are available in order to do screencasting for the Linux platform.

Today, i want to mention two complementary tools to support the screencasting process in Linux. The first is xvidcap. It can be found in the ATrpms repository. You only need execute the command, yum install xvidcap. It allows you define a rectangular section of your screen, then you can record all the things to happen there.

When you end to recording, probably you need editing the video generated. Then, I recommend to use Kino. Kino, is a basic tool for edit videos and as easy to install as execute yum install Kino. If you are familiar with vi editor you will find many key sequence use for edit text in vi, works for edit video in Kino, for example: "x" key allows you delete a character in vi, similarly, when you are editing a video with Kino, "x" key allows you to delete a frame. Very funny and wonderful for us, the vi users. :-D.

USEFUL LINKS

• ATrpms
• Screencast
• Tools A complete article to describe different tools for screencast in Linux.
  
• ScreenKast is a new project under screencast category. Automatically, it allows upload videos and publish them on internet.
• Istanbul is an advanced video editing tool, however, demands a lot of hardware requirements.
  

I'm user of Fedora Core Linux distribution, release 6, although at this moment release 7 is available.

Fedora as every major Linux distribution due to licensing issues cannot distribute in its official repositories (Fedora Base and Fedora Extra) software to playback MP3 or DVD files. However, there exist alternative repositories such as:

• fedora.us
• Livna
• FreshRPMS
• DAG
• NewRPMS
• ATrpms
• Dries

Some packages are incompatible between them, e.g. you can get compatibility problems if install livna and freshrpms at same time.

Recently, i'm interested in work with to do video tutorials for grid tasks and found that freshrpms repository fulfit my needs.

Useful Links

• Fedora apt and yum repositories
• Managing software with yum
• Fedora Core 6: Multimedia support (freshrpms)
  

How to clone a XEN VM

Hi,

today, I will describe what is the manual process to clone a virtual machine (VM) using XEN technology. (Fedora Core 6 (FC6) is the distribution installed in the server.)

Ok, assume I want to clone the VM "os_template". The information related to this VM reside in the file "os_template" located in the "/var/lib/xen/images" directory. Be sure, the VM "os_template" is shut off. Then, make a copy of the os_template file:

dd if=/var/lib/xen/images/os_template of=/var/lib/xen/images/os_copy bs=4k

Now, extract the VM configuration:

virsh dumpxml os_template > os_template.xml

this is the os_template.xml's content:

<domain type='xen'>
<name>os_template</name>
<uuid>3ca12152be4195b1fa67a0e857b9723d</uuid>
<bootloader>/usr/bin/pygrub</bootloader>
<currentMemory>262144</currentMemory>
<memory>262144</memory>
<vcpu>1</vcpu>
<on_poweroff>destroy</on_poweroff>
<on_reboot>destroy</on_reboot>
<on_crash>destroy</on_crash>
<devices>
<disk type='file' device='disk'>
<driver name='file'/>
<source file='/var/lib/xen/images/os_template.disk'/>
<target dev='xvda'/>
</disk>
<interface type='bridge'>
<mac address='00:16:3e:65:82:48'/>
</interface>
<console/>
</devices>
</domain>


now, modify next fields: name, uuid, source (file attribute), mac (address attribute). Save the modifications. I'll assume that the name given to your VM will be os_copy. Then, execute this commands:

virsh define os_template.xml
virsh start os_copy

The job is done!

Some relevant urls:

• XEN homepage
• Cobbler provisioning tool
  

Topico Caliente, Deployment en Caliente...

Since midst of 2006, articles has been written about new axis version, named Axis2. Many new features has been announced such as: improved performance, better memory management, among others, but i want to remark one of them, hot deployment.

The hot deployment open opportunities to develop new interesting projects and topics such as migration and service replication.

A lot of interesting articles and tutorials about Axis2 can be found in http://ibm.com/developerworks, go to section SOA and Web Services and search for "Axis2".

Enjoy it!

various...

I hope that everyone be okay.

Day by day is amazing how clever people take advantage of the features availables in internet. WEB 2.0 aims to be a social network, where people can share tastes, hobbies, among others common interest. Such manner, successful pages like del.icio.us, flickr, digg.com, youtube has been developed for specific purposes in mind share links of interest, pictures, news, videos and so on. Today, RedHat did an announcement launching the Mugshot page. Mugshot's aim is "an open project to create live social experiences around entertainment." Mugshot intends become a convergence point of exising WEB 2.0 sites, such manner in one place you can track all modifications done by a friend, for example you can see the new videos she uploaded to youtube, or new referenced pages in del.icio.us.

Finally, workplaces and education institutions has imposed mechanisms and policies to avoid access to ilegal sharing files. Such manner, many of us has found restricted to use popular p2p programs in our work or university. However, an interesting page g2p.org using the enormous Google capacity for crawl the web, provides link to directories that contain copies of e-books, songs, albums, and so on.

What will be the next great idea? think about it!

Groovy...

Groovy looks as another scripting language. But it takes advantage of to be a son of Java.

Nobody denies about the fact of the large set of java libraries available to internet: networking, processing management, distributed systems, virtualization and so on.

Scripting languages help to speed up the prototyping development, for example: ruby, python, perl, among others. Groovy is a scripting language that takes the best of two worlds: huge set of libraries and increase expressiveness of the Java language. Its first stable release to january 2007, asides count with an excellent companion book Groovy in Action becomes a Groovy an excellent prototyping tool.

Java programmers will found it very useful because allows easy lists handle, asides closure concept presents to Groovy as sophisticated java based tool, furthermore smart XML interaction, database connectivity, file management, and so forth.

Since Java(95) born, never a project exciting me so much as Groovy did. Remember, "Standing on the shoulders of giants". Groovy stands on Java giant, your project stands on Groovy?

Grid computing is a great idea, but a lot of work needs to be done in order to approach to scientific community from diverse branches of knowledge.

Tools and your creativity will approximate grid to most people.

• Groovy homepage All you need to start to play with Groovy.
• Groovy in Action (Amazon)
• Groovy in Action (Manning publications) with sample chapters, furthermore book's samples source code.
  

New features in GRAM4

Recently, an article about new features in GRAM4(aka WS-GRAM) has been published in www.globus.org.

Among new features is worthwhile mention:

• Improvements in fault tolerance support.
• Has been increased the number of active jobs.
• Has been adopted JSDL as job description language.
• A new enhanced delegation scheme.
• and more... (read the article)

Preliminaries tests shown a poor performance related to GRAM2(aka pre Web Services GRAM), however, efforts to address that issue are in progress.

Interesting links...

I want to share with you about a couple interesting links for grid manager and programmer.

GDTE plugin
Eclipse is a popular IDE, whose its main feature is the possibility to integrate easily new functionality inside it, through plugins. For grid services development GDTE is widely accepted in grid community.

• You need download eclipse and then install GDTE plugin.
• Besides, a set of small tutorials for diverse features available in the plugin.

Link for the "Newbie"

Globus Toolkit(GT) is the Grid concept implementation most widely adopted. However, the installation process could be painful because GT consist of a lot of components to need be configure. Globusconsortium has posted a tutorial to install a lot of that components in order to provide a basic grid infrastructure.

Another successful grid history

An interesting article was posted to computerworld. It describes how grid concept was used to compute drug compounds related to malaria. In six months of "grid processing", with around of 5000 computational nodes, 420 years worth of data was process in just four months.

RedHat supporting Virtualization

RedHat has been supporting developments on virtualization. Actually, www.openvirtualization.com, is a site supported by RedHat and inside of it you can find a lot of interesting resources related to virtualization under open technologies.

enjoy it!

Grid and Virtualization

The main subject of discussion is about grid computing, but remarkable topics to be discussed here are:

• Provisioning
• Adaptivity
• Virtualization
• Orchestration

Grid computing aims to provide an infrastructure to gather logically a set of distributed resources in a transparent way to end user. All infrastructure is built on top of non-proprietary and widely accepted protocols.

Important achievements to provide that basic infrastructure has been made, however, distributed environments involves new challenges to be considered.

An important challenge is to build autonomic environments and preliminary developments related to the items enumerate above require be made.

Then, that blog periodically will publish relevant information about it.

regards.