Virtualization architectures

The linux technical review presented an overview of the different type of virtualizations architectures. I recopied the table as a reminder.

From the Linux Magazine 01/2010 Linux Technical Review:

	Gleiche ISA	Verschiedene ISA
System VMs	Classic Hypervisors	System Emulators
	z.B.: Xen, VMware ESX	z.B.: Bochs, Qemu
	Hosted VMs	Co-Designed VMs
	z.B.: VMware Workstation	z.B. AS/40
Prozess VMs	Multiprogramming	Dynamic Translation
	z.B.: Linux, Windows	z.B. FX!32, Transmeta
	Binary Recoding	HLL VMs
	z.B.: Valgrind	z.B. Java VM

jsp:plugin

Rereading the Java EE 5 Tutorial I learnt there is the possibility to use the jsp:plugin to embed java applet into a page without having to take care of which browser is behind it. I still have to test this but this sounds really good.

commandlinefu

I bought a number of linux magazine during my week holiday and discovered a number of new interesting, useful things:

• Ubuntu One, a way to store data on some ubuntu servers to share it with other ubuntu users (I must check that)
• Writer's Cafe, a tool helping creative writing
• impro-visor, some GPL software working with lead sheets.

And one thing I really found useful is: commandlinefu (http://www.commandlinefu.com/). This site provides a way for people to advertise useful commandline tricks. I should probably follow them, I will learn a lot. And it already started.

I already learnt a new useful command: youtube-dl. Say you have some google URL:

http://www.youtube.com/watch?v=1504cSBhWG0

And you want to get the url of the file being downloaded, then you can use (-b for best quality and -g for just getting the url): $> youtube-dl -b -g http://www.youtube.com/watch?v=1504cSBhWG0

Of course this command has a certain number of options.

Desktop recording Suse

I have just tried a desktop recording software under OpenSuse 11.2: recordmydesktop. It really worked as a charm for the video part even with thesound.

Eclipse 3.5 Windows and Unicode and Subversion

File.encoding in Eclipse and strange encoding problem in JavaSource UTF-8 files

While trying to deploy the package I have been deploying, a few problem arised yesterday.

We first had checked out a Web application.

Afterwards we set the default encoding to UTF-8 for a few files in the Window > Preferences > General > Content-Type > Text > JSP .

We also changed the encoding in the eclipse.ini file, adding the following line to the java command -Dfile.encoding=UTF-8 in the eclipse.ini

We had strange text where umlauts had been destroyed. The text was in UTF-8 in UTF-8 files in the JavaSource directory. By Debugging, we discovered that they were also called by UTF-8 JSP or UTF-8 Java Files.

The solution has been to check the Application again. Afterwards the text was displayed correctly

Subversion problem while checking files with same names with different Case

The other problem we had, was caused by two files having the same names but with different case: file.jsp and File.jsp. This caused some kind of conflict when checking the file out with subclipse.

Adding .inc as content Type under eclipse

After spending much time looking for the place of the configuration for adding .inc as possible types for files in eclipse, I had to ask a friend again. So here is the place where you do it in Galileo: Window > Preferences > General > Content Types Choose Text > JSP > JSP Fragment And add *.inc to the list of files. You probably also should set the Default encoding.

Gradle - a groovy Make

So in my search for some maven solution. I fell on YAPMT (Yet Another Project Management Tool). I am not sure it does the same things as Maven. It uses Maven and looks much more like a script mechanism. So I will have to see whether it is suitable. While Maven is quite useful since it has a lot of plugins and a really well organized workflow. I would say that gradle seems to be like a groovy shell with a certain number of plugins for project management.

I will have to keep an eye on it.

Dojo Toolkit - Yet another javascript toolkit

After looking at roo, I noticed that they used the Dojo Toolkit for their default implementation of the web toolkit of the page. I Have not yet done a real comparison of the two frameworks. It seems to have more or less the same functionality as ext-js. I will have to keep an eye on both systems. At least from the licence point of view is Dojo more appropriate for companies, since it uses a BSD/Apache licence, where as ext-js under GPL ( I do not think that it has also a LGPL version apart from the core). Dojo seems to be composed of three parts:

• Dojo core
• dijit
• dojox

Dojo core contains a number of utility methods for querying web pages content and perform operations on it. Dijit is a widget mechanism. Dojox are extensions based on dijit.

URL Rewriting Code in Java

Some time ago, I had to take a look and have something work with URL rewriting. My colleague told me there was an URL rewriting tool called URLRewrite. I will later introduce it here: http://tuckey.org/urlrewrite/.

On Top of the Monitoring

So the new trend in naming of projects is to top every thing, in order to imply that these tools are similar to the top command. So the idea is to have a console (text-based) tool indicating what process or activity are currently at the top of their category (e.g memory consumption, processor last)...

So here are the few project I just discovered:

• htop
• innotop
• ApacheTop

And I suppose there are many others.

htop

htop is the closest to (the ;-) ) top, since it is a kind of enhanced top. I tried it. And it was quite nice.

innotop

The name of this one comes from innoDB which is one of the possible backend to a mysql database. I have not tried this tool but I suppose it is like top but just for a mysql database.

ApacheTop

A kind of top for apache request. I think I should take a look, because it might be useful for debugging purposes of our applications.