All the colors of Java and so on

Introduction : ODS or UCP?
I've been using DBCP and C3P0 for a long time. But, a few months ago, I started to have problems with them. For example, sometimes, no way to get any connection to my database (while it's still possible with my Oracle SQL Developer). So, I decided to look at the code of C3P0. What a surprise! Even if it's a very common pool for a lot of projects (such as Hibernate), it seems to be dead. No more development, code complicated with sub projects, no Maven integration (...ok, ok, even if you hate Maven, you have to admit that it is very efficient to modify the code of mavenized projects...). Thus, I looked for a new pool. Of course, I found the recent tomcat jdbc pool. But I finally decided to work with Oracle pool just because I only have Oracle databases.

So, this post is my history with Oracle pool.

When you look for pool features on Oracle doc website, you find to ways to implement it :
Oracle DataSource pool (also called ODS) and included in the driv…

I found it while I was surfing on the JDuchess french site. This site (and of course its author) aims to give the keys to self-teaching of the art of business.
Thanks to Mathilde Lemée (http://www.java-freelance.fr/)
http://personalmba.com/best-business-books/

Today, I had a problem between my Apache balancer and my Tomcat cluster. A virtual machine that was hosting two Tomcats was frozen. Something was wrong in my config and the Apache didn't show these Tomcats in error in the jk_status web interface. After a few minutes, I realized that the uriworkermap file was not configure on 'balancer' but directly on 'tomcat1' (one of the two Tomcats that were down).
So, I concluded that the Apache jk doesn't do any test on a worker if it isn't mapped with an uri.
But let'go back to my virtual machine that was frozen. It was not completely dead and a telnet 8010 was responding. Thus, my first conclusion was that I had a problem with my Apache. BAD WAY!!! The telnet was not efficient. I demonstrated that with a tiny perl script found on the net made to simulate an ajp ping.
You can use the script as this : time ./ajp_ping.pl server:8009
Many thanks to the author of this script. I don't have the link to his post anymor…

I n my company, I have to deal with many Spring based applications deployed on a Tomcat cluster. For each one, we set a property 'webapprootkey' in the web.xml file to avoid errors on startup. Today, I decided to dig about that (... erratum... I decided to tell Google to dig about that). Thus, I found this excellent post.

http://groups.google.com/group/riotfamily/browse_thread/thread/9a0edf69575d3ab6?pli=1

Hi all,

when deploying two applications build from the riot skeleton within the same Tomcat servlet container, you get an IllegalStateException: Web app root system property already set to different value: 'webapp.root' = [/Users/joe/Workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/webapps/webapp-A/] instead of [/Users/joe/Workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/webapps/webapp-B/] - Choose unique values for the 'webAppRootKey' context-param in your web.xml files!

I will try to explain where this comes from and how …

This is what to do to fix this kind of problem :
tar cvzf rpmdb-backup.tar.gz /var/lib/rpmrm /var/lib/rpm/__db.00* rpm --rebuilddb rpm -qa | sort
The first line is to backup your database The second to remove locks The third to rebuild your database The fourth to check if all is ok

Marco sent to me this excellent (EXCELLENT!!) link. As always, this is not a presentation for rabbits!
http://www.pythian.com/news/392/pythian-goodies-oracle-disk-io-basics/

grep "Invalid" /var/log/auth.log | grep -i ssh | awk '{a[$1$2]++}END{for (i in a){print i " " a[i]}}'

Thanks Marco!

I just write here some informations I found on the web. On my Linux Ubuntu 9.10 64 bits, the flash plugin sometimes doesn't register mouse clicks. To fix it, edit the following file by doing :
sudo gedit /usr/lib/nspluginwrapper/noarch/npviewer
and add this export
export GDK_NATIVE_WINDOWS=1
like this
#!/bin/sh # # nsplugin viewer wrapper script... OS="`uname -s`" ARCH="`uname -m`" NPW_LIBDIR="/usr/lib/nspluginwrapper" export GDK_NATIVE_WINDOWS=1
if test -z "$TARGET_OS"; then ...
Enjoy!

Be careful, this is an awesome video! You can also observe that the programmer is using an Acer netbook.

Today, we have encoding problems with legacy apps written in PHP. After some discussions and some googlings, I found this interesting post :
http://www.sitepoint.com/blogs/2008/09/10/issues-with-cultural-integration/
You can read in it : Latin1 on the inside, utf-8 on the outsideEmbed utf-8 within latin1I copied-pasted just a few lines of code :
// declare that the output will be in utf-8 header("Content-Type: text/html; charset=utf-8"); // open an output buffer, capturing all output ob_start('output_handler'); // when the script ends, the buffer is piped through this functions, encoding it from latin1 to utf-8 function output_handler($buffer) { return utf8_encode($buffer); }
Excellent!

As I was surfing on eclipse.org, I found this link which contains a selection a plugins. I've already tried someone which are very interesting. So, do like me : enhance your Eclipse!

http://www.ajaxline.com/best-eclipse-plugins

#!/bin/bash # Script created by # Romeo-Adrian Cioaba romeo.cioaba@spotonearth.com # Super minor updates by jason.melton[at]gmail[dot]com # Updates by Alejandro Cuervo 3[at]cuervo[dot]net # more very minor updates by damien[at]groovey[dot]com # Released under GPL
echo "Closing Firefox" sudo killall -9 firefox
echo "Downloading and instaling Getlibs for required libraries" wget http://www.boundlesssupremacy.com/Cappy/getlibs/getlibs-all.deb sudo dpkg -i getlibs-all.deb
echo "Removing previous installs of flash:" sudo apt-get remove -y --purge flashplugin-nonfree gnash gnash-common mozilla-plugin-gnash swfdec-mozilla libflashsupport nspluginwrapper sudo rm -f /usr/lib/mozilla/plugins/*flash* sudo rm -f ~/.mozilla/plugins/*flash* sudo rm -f /usr/lib/firefox/plugins/*flash* sudo rm -f /usr/lib/firefox-addons/plugins/*flash* sudo rm -rfd /usr/lib/nspluginwrapper
echo "Installing ia32-libs and nspluginwrapper" sudo apt-get install ia32-libs nspluginwrapper
echo "Get…

Today, Marco gave me a link to a post made to understand what is functional programming (you know that Microsoft F# is arriving?) :
http://www.defmacro.org/ramblings/fp.html
Thanks Marco!

Good news for french readers! Guillaume Lebur translated this excellent book.
http://blog.infosaurus.fr/public/docs/DDDViteFaitPartie1.pdf

I've just finished the two days long training session to be a Scrum Master. These two days were lead by Jeff Sutherland (in collaboration with Xebia France) . Of course, don't imagine that you will be great a Scrum Master at the end of the session. As Jeff said, were you a good driver just after obtaining youri driving license?

In this post, I will try to summarize notes I took during the course. It's not exhaustive but it wil give you a global idea of what is Scrum and what should do a Scrum Master.

But, before starting, let's return to the title of this post : "I realized I was a ScrumButt Master". Humm... what's that? Jeff said something very interesting . He asked people about who had already tried Scrum. Many ones in the assistance raised their hand. So, why were they here? ... Ok, let's do another test : can you give me the average velocity of your team? Only two answers iin allt the room. And that's why I was here. As many people, I tried Scr…

This is a little tip you must know if you have an "in-house" maven repository mirros (such as Artifactory) and if you want to access to an exotic one.

What's an exotic repository? My definition of that is a repository hosted by a developer isolated somewhere on the web. Of course, it's not a mirror of the official one. By the way, you should not declare it on you "in-house" mirror but simply write the following lines in your pom.xml :

<repositories>
<repository>
<id>violet.repo</id>
<name>Violet's Maven repository (public access)</name>
<url>http://violet.sourceforge.net/maven2/repo/</url>
</repository>
</repositories>



Now, imagine you try to retrieve an artefact. Muupp... error! You miss to declare an exclusion in your settings.xml to inform Maven that it should not use your local mirror to get it. Thus, this is an example of what to do :

<mirrors>
<mirror>
…

A good starting point is Fiddler :

http://www.fiddler2.com

Of course, it's free.

You can't imagine how Firefox loves to write temporary files. I realized it on my Acer Aspire One with its ugly 8GB SSD. An excellent tip I read on the web consists in mounting a directory in memory and configuring FF to use it.

Let's go :

sudo gedit /etc/fstab

Add the following line :

tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0

In Firefox, open this internal URL :

about:config

Right click to add a new string entry :

browser.cache.disk.parent_directory

Set its value to

/tmp

Reboot your machine and appreciate...

Of course, this tip is certainly portable on Microsoft Windows with softwares like RamDrive even if I presented it on Linux.

I'm currently reviewing some scripts to install a Tomcat cluster. A nice way to do that is to have a common Tomcat installation and the minimum needed for each node. There's a an excellent introduction on the subject by Filip Kanik :

http://www.springsource.com/webinar/large-scale-tomcat-deployments

Then, you will find here an example of the run.sh file introduced by Filip :

http://sirinsevinc.wordpress.com/2009/07/20/deploying-multiple-tomcat-instances/