romjethoughts

Soti MobiControl - managing a bunch of embedded devices

2012-01-06T04:50:00.000-08:00

Hi all,
this story differs from most of my work , but my customers asked to have a look to a tool for managing embedded devices part from the big application where I have done a huge work of reengineering with OSGi foundations....
I was asked to grab from the devices different data like:
- JVM version
-application version
- database version

using different files present in the installed application inside the embedded PC (windows mobile powered)
Soti provides a tool to grab data but it 's very conviant for only basic tasks so I am about discussing with Soti company to try to embed a scripting language to be able to write powerful scripts ....
So now wait & see how this company settled in Canada will react to improvements of a very small customer...

happy coding

OSGi and weird classloading issues

2012-01-02T05:59:00.000-08:00

I just faced a weird Classloading issue in felix with a bundle using Castor XML to do some marshalling of business classes into XML...
I followed an advice from the felix dev mailing list and set the Felix logging level to 4 (getting very useful messages) ... With this material I fixed my problem while setting the property : org.osgi.framework.bootdelegation to org.xml.sax and it works!!!

Happy coding

OSGi Book ...... coming very soon

2011-12-20T15:10:00.000-08:00

Hi all,
I'm very excited to say that the book is finished now and is about going printed tomorrow.... After several monthes of infernous work , it's a very good thing to see it completed.... Don't worry about what to do next, I've several ideas ....

I'll tell you more soon when it will be accessible online on the editor website...
Happy coding & merry christmas

Thinkpad X201 , debian & sound

2011-12-08T01:29:00.000-08:00

Hi all,
a few lines after several days fighting with my machine to get a fully functional solution with audio capture on Linux....
I got a very good result after using in the /etc/modprobe.d/alsa-base.conf
options snd-hda-intel model=ideapad

This model was fetched after getting from my system the list of Codecs :

Now have a look into the ALSA docs while doing this...

/usr/share/doc/alsa-base/driver/HD-Audio-Models.txt

You can now use the alsa command to force reload:

now the alsamixer should show every channels:

and screen capture should be nice now.....

Happy coding (screen acquiring)

Git , shell and a proxy on the same boat...

2011-11-03T09:16:00.000-07:00

Hi all,
just encountered a small problem so this is the solution I used to succeed in cloning a repository from the guthub website using the git command at my customers site.
They use a corporate proxy (squid cache) and trying to simply setup the proxy with the standard export from my shell:
export http_proxy = ....
does not work and git fail with such message:
git failed to connect to ... operation now in progress

I wished to use the https URL but it failed so I switched to the standard HTTP protocol (same URL removing the 's' character from the protocol part) , I succeeded with one another trick while setting the port number explicitly ....

This is an snapshot from my shell showing the latest trick...

Happy coding
jerome

Java One feedback - When Oracle killed Duke party

2011-10-15T06:38:00.000-07:00

Hi all,
another post relating my recent trip to San Francisco and the week spent in Java One....
My opinion is :

too many overlapping on session themes , with same speakers, same set of slides, same exemples for 3 or 4 sessions ....
some very handy themes have been totally forgotten (what about NIO ?)
too many sessions cancelled
too many sessions totally uninteresting (no concrete feedback, bad presentation material...)
network infrastructure was very poor (unable to connect to the Oracle wifi network during the whole week, obliged to use the Hilton wifi bandwidth unsufficient for the huge number of simultaneous connections)
using different sites for the different sessions without providing any assistance to attendees is just a scandal...Moscone Center was already full with the Oracle World sessions...

As a summary just a few very valuable sessions (may be 3 in the week plus the Java University day )...
I am convinced that Oracle tried to make money with this event and for 2800 dollars of registration I am far from getting a concrete return on my investment... I don't like Sting much so seeing Sting in private concert is not for me a real argument for becoming found of Java One ..I would have preferred many wonderful sessions with major speakers than seeing my money invested into such event..
I don't think I will return to the big Java party...

May Java be with you

I love visual vm!!!

2011-10-15T06:22:00.000-07:00

Hi all,
after JavaOne where I attended all sessions devoted to JVM & performance and preparing training courses dealing with those subjects I spent a few hours playing with Visual VM, this tool changed a lot since my latest usage...
Impressive tool capabilities enhanced by several plugins , my preferred is of course Visual-GC...

This single plugin is by itself sufficient to understand where most performance problems arise and is a tremendous tool to explain memory layout and GC work....

May Java be with you

JAXEnter article

2011-09-26T06:58:00.000-07:00

For those wishing to have a gentle introduction to OSGi please take the time to read my article (in english) and available here...
feedbacks welcome

Goodbye Darmstadt , hello San Francisco

2011-09-26T06:16:00.000-07:00

Hi all,

I spent 2 wonderful in Darmstadt last week, for the OSGi Con Europe conference. 2 exceptional days with the best actors in the OSGi world:
- Peter Kriens of course
- Neil Barlett (bndtools father)
- Mike Francis and Richard Nicholson from Paremus , most advanced distributed OSGi project

- krister Larson from MakeWave (knopflerfish father)
- and many more

Very interesting conferences, beautiful barbecue in a very sympathic atmosphere...
Next week I 'll be for the first time to the big Java fiesta : Java One....
I'll start my week while working on sunday to attend a Java university day dealing with extreme performance, a very valuable subject ....
May Java be with you

Why Maven can't work ?

2011-09-12T04:52:00.000-07:00

Hi all,
another flame-war thread ? No, definitely not, but you 'll find above a pragmatic analysis of why Maven projects fail ....

Maven repositories are never up .... Have you ever seen an ibiblio repository finding your library ?
Maven POMs are stupid, descriptors are ugly and useless
Maven makes simple things tricky and complex ones impossible... Triyng to rule the project lifecycle is a very tricky challenge....A simple example for this point is how to deal with publication of multiple jars with Maven (yes it's possible but for me it's very tricky) like publishing API & implementation jar files.
Maven philosophy goes wrong... How could the Maven integrate well with most of the Java projects ? The plugin philosophy reaches its limits.... Why Maven handles project versions as plain strings ? How could you easily manage versions numbers like 2.5.6.FINAL or 3.2.1.RELEASE ? It 's stupid and useless , Maven should definitely use a numbering scheme like the one purposed by the OSGi staff? I can't recommand enough you to read this whitepaper : www.osgi.org/wiki/uploads/Links/SemanticVersioning.pdf,

These different points make Maven very hard to use in any Continuus Integration process... I faced contexts where an Ivy engine dealing with dependencies described as Maven POMs where unable to imagine what was the ordering relationship between 2 versions of the same component.... I finished a few weeks ago to set up an Hudson repository hosting a quite huge project with over 300 OSGi bundles (each one having its own dependencies set)...

I am an Open source advocate but availability of the repositories is one big problem for me , because after being unable to deliver versions for a few days because of unusable repositories , I think that many companies would be ready to pay for having such service .... Moreover I think that most companies all over the world would be ready to pay for getting strong repositories that is to say to have complete strong & robust sets of software components... This is one the main themes of my lunches with Peter Kriens in Lansargues -)

May Java be with you

Next trips

2011-09-06T00:43:00.000-07:00

Hi all,
I am about given a talk in OSGi Con Europe in Germany (Darmstadt near Francfort) and I will assist for the first time to JavaOne in San Fransisco from 2 to 6 th October..... It may be the way for me to buy the news Blackberry 9900 or 9930 smartphone (9900 should be available soon in France, 9930 won't be)...

I must finish my slides for the upcoming talk , don't know yet if very graphical slides are best than more boring but full of material ones ? It's a matter a style I guess and I am not very confident with all Office suites ...

Meet you soon somewhere where Java rules

Jerome

SQLite performance tuning

2011-09-05T06:40:00.000-07:00

Hi all,
just finished a very interest work : a technical study of SQlite tuning.
I developed a custom application deployed as a set of OSGi bundles to benchmark some set of parameters of the SQLite connections. I used intensively the concept of PRAGMA as taken from SQlite architecture.
Official SQLite pragma doc
Pragma are set using standard statements while initializing connections and enable us to fine tune SQLite behavior.
The results from this work are wonderful, when theory meets concrete experience :

reducing the number of transactions is a must have in your code , even for local ones, transactions are expensive
the synchronous pragma shows how file systems notifications can be expensive
mastering journal may be another way to reduce I/O times
using SQLite into EXCLUSIVE way reduces locking so saves many time

I did not have time enough to develop use cases showing concrete effects of tuning parameters related to locking (READ_UNCOMMITTED and SHARED_MODE) but may be in the next days..... Such use cases require me to add a little bit of complexity to my framework to handle shared resources among different transactions that is to say :

a transaction running with inserts into a table TEST
another transaction running with queries like select count(*) from TEST

Shared mode may be a good way to the second transaction not waiting for the first one to be committed....

I used the xerial JDBC driver with success : link to Xerial Website

Just a remark , it seems that SQLiteConfig class introduced by the framework does not work , it keeps bringing me null connections while setting different pragmas... Setting them directly through JDBC statements over the java.sql.Connection obtained from DriverManager works nice....

It's quite impressive to see how easy it is to ask to a database not to check integrity constraints and to see performance raising .....

May Java be with you

Jerome

Java Renaissance: EclipseCon keynotes 23/03/2011

2011-03-23T10:21:00.000-07:00

Hi all,
I just left the keynotes from EclipseCon 2011...
This morning the course was very appetizing with a keynote hold by John Duinovich & Mark Reinhold from IBM & Oracle ... The aim of this talk was to show how IBM joined the OpenJDK ...
This talk was a way to get first details on the Java language evolvings since latest Java 6 is about 5 years old now..
IBM contributions to OpenJDK aims to speed up JCp process, optimize the JVM and may be optimize costs for both giant companies.
This talk gave me visibility over the next steps for Java:
- Java 7 release date (GA) is 2011/07/28
first RC version is expected on 2011/05/11
It will bring us :
project Coin (JSR 335) , a few languages improvements
More new IO API
Fork/Join API

language improvements sound to be gadgets for me with introdction of support of Strings types in switch ..yes but switch is a non oriented design so what ?

Java 8 : release date :late 2012
integration of the lambda project (aka closures)
introducing Process Control API, Date & Time API and many more
Modularity & support for OSGi is on the main goal of such version
Defining dependencies using meta data (a la OSGi)
enabling to deliver .rpm, .deb and other distributions formats while using mvn repositories to store dependencies

Pretty program -)

Java 9 first overview without any release timing:
enabling a better handling of new hardware platforms with different APIs:
NUMA
Multi agressive cores
handling huge heaps (dozens of Gb)

Reification is on the pipe too , getting a concrete answer to type erasure problem appeared since Java 5
better communication with scripting languages is on the road too with the Meta Objects Protocol

Happy coding from California
jerome

First conferences in OSGi Con

2011-03-22T11:22:00.000-07:00

Hi,
I tried to attend my 2 first conferences in OSGi Con this morning, results are not so beautiful:
- first one dealing with distributed OSGi , interesting subject , but a speaker very hard to understand, very confusing in his speech
- second one dealing with Apache Aries , cancelled

I hope to more lucky later

jerome

Surfing bear

2011-03-21T15:08:00.000-07:00

Hi all,
Jerome aka romje aka the bear crossed the Altantic to attend the annual mess of the OSGi users.
I will have a talk on next Wednesday , I'm a little bit excited even if I fear for my lack of skills in english oral communication. -)

So the bear in America (Santa Clara California) had the opportunity to meet after more than 10 years of electronic discussion by email , Cedric Beust, we shared a nice lunch ...

Weather here is not very clement, it's very cloudy with many rains but who cares ?
Golden gate was wonderful yesterday...

happy coding
jerome

Squeeze is here ..my new laptop too

2011-03-02T14:44:00.000-08:00

Hi all,
I received last week my new laptop: a Lenovo Thinkpad X201 with 8Gb RAM , 256 Gb SSD disk...
Quite the same machine as my previous Sony VAIO Z12 excepted that:
- cooling works nicely (working with a CPU at 85 °C is very hard and very bad for the chocolate)
- all devices are nicely managed by the 2.6.32 kernel patched by the Debian team

I don't need anymore to have handcrafted to work ...(like with the ArchLinux used on the VAIO)

The machine is horrible but seems to be very well designed...

I used this occasion to install Xen 4.0 on the debian & all works perfectly , even not a single problem ( -) ) to get up and running my first DomU on this machine....
I guess I'll find soon some time to get at very quick howto on this subject...

I will return on OSGi code

Happy coding
Jerome

Jboss 5.1 & VFS behaviour

2011-01-15T10:33:00.000-08:00

Hi ,
this post is relate'd to a new feature of the Jboss 5 release called 'VFS'. Asany veteran developer you may have guessed that this feature is a way for Jboss team to map any file (bringing one abstraction layer over the file system behaviours on different OS).
This abstraction layer is due to the strong desire for JBoss to target the developpers and to bring attractive features like hot deployment.This feature is quite useless in any production ...
Defaut configuration of the VFS component into the Jboss micro container induces weird problems with filesystems filling up still exploding!!!
It turns out that cache misses induce reload & unzipping of the components...

I faced this problems and found a quite solution using an hidden parameter into the Jboss components...IterableTimedVFSCache inherits an attribute called defaultLifeTime..This parameter used in conjonction with resolution (fixed to 60) enables us to define cache retention..Using a very high value (as an Integer 2^31 -1) gives a quite good solution...

Problem fixed
Hopes this helps
May java be with you

Jerome

OSGi & Declarative Services

2010-11-02T07:58:00.000-07:00

Hi all,
the OSGi MasterClass was the way for me to discover benefits from the standard OSGi declarative services and a tremendous tool : bndtools. Bndtools is quite sufficient to rediscover Eclipse (I left this tool from more than 4 years )...
Declarative Services are a marvellous way for me at customers site to remove the bad Spring injection (limited because static and coming with dozens of libraries ) by a small & efficient way to inject dependencies .
A next entry will introduce this subject with code & screenshots....
I used extensively bndtools to gain:
- full control over OSGi Meta information
- efficiency (it's a quick and robust way to develop OSGi bundles)

More Neil Barlett (coder of bndtools) is a very nice guy , impressive by his quickness to adapt the product to user experiences , very pleasant & with a deep knowledge of OSGi architectures.

Happy coding
jerome

OSGi MasterClass

2010-10-14T01:02:00.000-07:00

Hi all,
I 'm just returning from 2 days spent in girona (Spain) for the OSGi MasterClass lead by Peter kriens et Neil Barlett.... The not mandatory introductory day was fantastic , it was the way for me to discuss with Neil & Peter, to use bndtools (I just used bnd from ant before) and to discover OSGi declarative services...
The first official day was a lost of time with a repeat from what should have been mentionned as a requisite for the course....
Don't care I left because too many things to do ... But I think that this masterclass could become a wonderful source of knowledge with a little more organisation.....

Happy coding
Jerome

Linux running on the Sony VAIO VPC Z1

2010-08-27T07:16:00.000-07:00

Hi all,

I just received (last week) my new laptop, a wonderful machine : Sony VAIO VPC Z1..
Small, very lightweight (1.5kg) , elegant with plenty memory (8Gb) and many disk space (500Gb 7200rpms).
I started with the default install (windows 7 profesiional) to check that everything went ok...nice it works
Now, let's go to resize the initial partitioning...reduce the windows partition to 100Gb it's enough for me to setup some games... Booting on a CD image running a LiveCD with GParted and that's it..
Ok now let's try to install Linux on this marvellous machine...
The hell starts here...
Trying to install with debian Lenny CD (5.0r5) and was unable to find network card or my wifi ...
Ok no problem, let's try with the debian testing, a few minutes later I came back with a fresh netinstall CD just downloaded (and checked through MD5)...No way to install on my disk, it's not detected... Ugly situation
Ok I 've got a fresh sidux (debian distribution based on debian sid ) running a 2.6.34 kernel....It runs but the console obtained is unusable (bad colors) and text unreadable once displayed..Oops..
One more test with debian sid, same result...

Damned Linux can't run on VAIO ?
Hopefully not.. I found this page which saved my life: http://lowl.net/linux-vaio-vpc-z.html
I followed the different advices and obtained a running machine after compiling a quite fresh 2.6.34-5 kernel from source, patching it to get a good driver for the intel 915 graphics card embedded, adding modules to get keyboard shortcuts functional...
Status :
-> network is ok (wifi too)
-> i915 works well
-> trackpad hangs from time to time
-> bios flashed succesfully to get a running hybrid switch button ....State saved after each boot..So selecting your card after booting now works
I didn't try to use WWAN services (don't understand what it exactly means) nor the integrated webcam (no application using it ..amsn maybe ? but I don't use instant mesenging solutions )

Linux rulez and debian rocks..

Bug with Java Networking with my debian Squid (aka testing)

2010-02-24T09:34:00.000-08:00

Hi all,
upgraded to testing a few weeks ago, I did not use my Java samples for a while and while trying to update Idea IntelliJ or Netbeans I faced network failures (No route to host ..)..I already encountered clever problems like these , so I guessed that it was a dual stack problem...
So I googled for the way to unset IPV6 support on my box ..and it worked...
My problem was annoying because networking was working with wired connections but not with wifi...Eveen my training samples (JDBC connections on my local Postgres database fail)
To unset IPV6 support:
/etc/sysctl.d/bindv6only.conf
change to net.ipv6.bindv6only =0

Now enjoy Java networking

jerome

And now enjoy

working with IntelliJ - First feedback

2010-02-01T07:57:00.000-08:00

Hello,
This is a quick summary of my first weeks of quite intensive usage of IntelliJ (I bought the 8.1 commercial version upgraded to 9.0 commercial one not community one):

quite lightweight (cool)
did'nt see any huge bugs (no hangs or explosures of your IDE)
no documentation at all, it's very confusing to see a commercial with a so poor documentation:
a few very incomplete PDF documents,
no serious documentation,
outdated FLash demos (nice to use proprietary formats) ,
very annoying suggestions dealing with style and other themes: simply ridiculous, no interest to loose CPU to fix coding style problems while they can fixed on any CI server!!!!
this latest point is surprising when you use the Jetbrains product which is not so bad even if I prefer Hudson (more simple and lightweight)
no strict equivalent from Eclipse and netbeans quick fix buttons so nice to use
horrible product ergonomy , the incredible product list of features induces with such a design a very hard to use UI , with menus full of plenty options....You 'll loose an incredible amount of time while searching through the menus...The option is there but where !!!
Another annoying aspect of IntelliJ is another form of the lack from documentation : plugins ecosystem!!! you 'll find a page with the complete list of plugins but no way to know if these ones are obsolete (deprecated), I don't even know if Jetbrains people know that many of referenced plugins are useless ornow integrated as is in their product !!!
Internal product architecture can impose sevral limitations while trying to use advanced features (remote debuging,jconsole usage)
JEE integration works but for a small range of servers, I had the bad inhabit to use dozens from servers with my Netbeans..IntelliJ is far more restrictive...

May Java be with you
Jerome

First steps with Groovy

2009-10-20T07:28:00.000-07:00

Hi all,
my latest toy : gradle was for me the trigger to dive into Groovy.
As usual I wanted to make a small log parser for one application hosted on Jboss at customers site , trying to follow client connections, generate statistics (average response time, number of transactions handled, number of errors & so on)
Playing with Groovy was for me a chance to test with a feature I just heard about : closures.
My parser suits well to these tests , because depending on certain messages (patterns as definbed in the regular expressions world) I must trigger different actions....This may suit perfectly to a quite advanced usage of closures..
Storing in a map keys as strings (the different messages) associated with values as closures (reactions for these messages) I get a quite handy, extensible & powerful tool...
So I tried to invoke my closures directly fetched from my map..This led me to the small code snippet following..

def Closure f1={println('hello from f1')}
def Closure f2={println('\n\nhello from f2\n\n') }
def Closure f3={println('hello world from f3')}
def map = ['1':f1,'2':f2,'3':f3]
def values = ['1','2','3']
values.each { it -> def closure = map.get(it) closure.run() println ( 'closure type = ' + closure.class) closure.class.methods.each{it2 -> println('Methode de la closure = ' + it2.name)}}
Now running this code from the groovy interpreter gives me :
-\ --(\ \ 16:10\ :%)-\ -\ groovy test_closures.groovy --\ (Tue,Oct20)-- hello from f1 closure type = class test_closures$_run_closure1 Methode de la closure = doCall Methode de la closure = doCall Methode de la closure = run Methode de la closure = setProperty Methode de la closure = getProperty Methode de la closure = clone Methode de la closure = getParameterTypes Methode de la closure = setDelegate Methode de la closure = getOwner Methode de la closure = setResolveStrategy Methode de la closure = getResolveStrategy Methode de la closure = getThisObject Methode de la closure = isCase Methode de la closure = call Methode de la closure = call Methode de la closure = call Methode de la closure = getDelegate Methode de la closure = getMaximumNumberOfParameters Methode de la closure = asWritable Methode de la closure = curry Methode de la closure = getDirective Methode de la closure = setDirective Methode de la closure = invokeMethod Methode de la closure = getMetaClass Methode de la closure = setMetaClass Methode de la closure = wait Methode de la closure = wait Methode de la closure = wait Methode de la closure = hashCode Methode de la closure = getClass Methode de la closure = equals Methode de la closure = toString Methode de la closure = notify Methode de la closure = notifyAll hello from f2 closure type = class test_closures$_run_closure2 Methode de la closure = doCall Methode de la closure = doCall Methode de la closure = run

That's it ... works nicely...
I can now code a quite powerful parser with Groovy
Happy coding
Jerome

PS:
don't know why but blogger site keeps removing line feeds!!

Gradle, TestNG on the same boat

2009-10-14T04:45:00.000-07:00

Hi all,
while preparing one training for my students from the insia engineering school in Paris, I got the way to use seriously TestNG from Cedric Beust and found a very valuable product far more powerful than JUnit without any hassle:

very close to major concepts introduced by Junit
just bringing more power without adding any cost
going one step beyond JUnit with :

distributed testing (master/slave architecture),
dependent tests
group of tests

This course was so the way to discover unknown feature present in recent JUnit releases like timeout tests.

I need to make a last effort to integrate TestNG into Gradle and add a Cobertura task to analyze the testing area covered by Unit testing.

Open source is magic bringing many beautiful things for those ready to invest a little time..
I will upload soon the whole training course slides and the project with its gradle build file...

See you soon
Jerome

Gradle : the Maven killer ?

2009-10-12T04:35:00.000-07:00

Hi all,
a few weeks ago, launching a troll on the old Java list from Strasbourg university, I got useful answers refering to Gradle ...What is that beast ? I decided to test this tool and I after playing around for 1 or 2 hours that it 's a great tool with plenty advantages:
- concise like Maven should be
- powerful (made in Groovy and natural Ant integration, using Ivy as the dependencies management tool)
- fun , always fun to play with a new toy !!!
- intuitive : no more Maven hassle when trying to do something not imagined by The Massol team... No need to tweak into the Maven kernel to add hacks.... It's easy and simple...
- well documented : a single PDF file with more than 150 pages, not bad for a so new product isn't it ?

What 's wrong with Gradle ? Don't know yet, like any new toy you may need a small period to get familiar with...

For those who don't have goodgled yet, this is the link : http://www.gradle.org/

May Java be with you

jerome

Hard life of freelance

2009-09-04T10:13:00.000-07:00

Hi all,
for the first time , this entry is not a technical one but rather the expression of my current humor. The economic 'world crisis' obliged me to accept a contract with a company named freelance.com installed in many countries. The french local agency brought me a contract for 3 monthes, that was the starting point for problems:
- they asked me to reduce my price to get the contract, I agreed following one single condition :to have immediate payments for my bills,
they still don't even pay me for the July bill , they claim to be about proceeding to the payment...but not using an electronic withdrawal!!!

- they started asking me for papers, to ensure my company exists and is ok with all social organisms, that 's ok for me but after providing 10 papers they keep asking for new ones...

- they add a requirement for me to get a special insurance covering damages made at customers, I subscribed for such contract but now there 's a problem with the starting date of this contract which is 15 days after the filling of the commercial linking my company to freelance.com

Conclusion:
this company (or at least the french agency) is just a cheaters organism living from others work and playing with money earned by others!!!
they are even not able to do the single important thing from my point of view: paying me for the job done...

May Java be with you
Jerome

Ubuntu 9.04 : final version?

2009-06-03T14:21:00.000-07:00

Hi all,
upgraded one of the 2 systems ofmy laptop from Ubuntu 8.10 to 9.04 and discovered a product able to become a disaster for the whole open source community:
- machine hangs (freezes) without any logs, no way to get a console or any handy solution to get control on the machine
- gcc (and g++) are quite unusable, nothing compiles with severe errors, while in the same time code compiles fine on my goold not so old Lenny machine...

I wondered about the time the Ubuntu team left this version in testing state, because using it for a few hours is sufficient enough to discover it's at a beta stage!!!

Happy coding (but not on Ubuntu)
Jerome

The perfect desktop?

2009-04-06T03:35:00.000-07:00

Hi all,

experimentating different window managers on my laptop and desktop, I discovered one week ago a solution which shounds very good to my hears: awesome. A very tiny,powerfull and flexible WM.

I'm not mastering LUA (the language used for configuration) but it's quite easy to read and adapt...

I'll upload here config files and screenshots of my new desktop environment.

Happy coding

Jerome

Slides from the Solutions Linux 2009 conference

2009-04-06T03:32:00.000-07:00

Hi,

I will upload here my slides for the 2 conferences I hold during the large french Linux celebration:Solutions Linux. I was invited by Sun Mircosystems and Alexis Moussine Pouchkine to give concrete feedbacks on a project using OpenMQ. The second conference was an official one, dealing with an introduction to the OSGi platform....

Slides coming soon...

Cheers

jerome

Running Hudson web app on Jetty (HighTide)on Debian

2009-01-10T15:30:00.000-08:00

Hi all,
while setting up my environment on my new big server (running xen server 3.2.1 on Debian Lenny) and while setting up a VM dedicated to hosting SVN and hudson, I decided to use a fast & efficient web server : Jetty. I found some debian packages dedicated to the professional packaging of Jetty :HighTide.
First attemptto run hudson after starting Hightide as a service: hudosn complains about a missing environment variable HUDSON_HOME ( I changed the default value because I did'nt want to make many changes in the filesystem permissions
to allow thejetty user write in the /usr/share/jetty folder). This is a quite surprizing behaviour because my first attempts to run HUDSON on glassfish and jetty where very friendly,no problem.
I made a small patch to the /etc/init.d/hightide script to add an option to the JAVA_OPTIONS variable after setting the HUDSON_HOME env variable into the /etc/default/hightide script as usual in the Debian world.

This is a significant part from the script launching HIGHTIDE server...

#####################################################
# Add jetty properties to Java VM options.
#####################################################
JAVA_OPTIONS="$JAVA_OPTIONS -Dhightide.home=$JETTY_HOME -Djetty.home=$JETTY_HOME -Djava.io.tmpdir=$TMP -Dhudson.home=$HUDSON_HOME -DHUDSON_HOME=$HUDSON_HOME"

This is not the most perfect solution but it avoids some dirty hacks with file permissions.... I just regret not to have access to the latest build of Hightide as a debian package (I guess that Mortbay guys do not have an automated process to build .deb packages).

But now I can start/stop/restart/check server status as any other Debian service.
Happy coding
Jerome

Creating slideshow in a few clicks

2009-01-08T05:49:00.000-08:00

Hi all,
As a casual instructor I must do training courses, slideshows dealing with concepts and tools.
I searched for a while how to create easily visual demos. I just found it, it's free, sexy and quiet friendly : wink. Grab it here. I tested the windows version but a Linux seems to be available (for x86 Linux boxes, not AMD64 ones but who cares with VirtualBox or xen).
Impressive features, lightweigth, generate output in various formats:

HTML
SWF/Flash
PDF
binaries (.exe)

It's a must one.Thanks for this excellent work to its author..
My first attempt is not the best sample of what can be done with wink, but it enjoyed my customers...(How to create & deploy a Web Service with Netbeans 6.5/Glassfish in a few minutes).
Happy coding
Jerome

Xen 3.2.1 on Debian Lenny

2008-12-30T07:50:00.000-08:00

Hi all,
this is a small entry to store a few tricks while dealing with Xen on Lenny.
After creating a VM you 'll try to ssh to it ...
But if you see a clever message:

PTY allocation request failed on channel 0
stdin: is not a tty

Then you must add a few things to your configuration,
on the debian guest just ensure:
- to have udev package
- to have the /dev/pts entry into your fstab

So:
>aptitude install udev is your friend


and the contents from the /etc/fstab must be something like this

dev:~# cat /etc/fstab
# /etc/fstab: static file system information.
#
#                
proc            /proc           proc    defaults        0       0
/dev/sda1 none swap sw 0 0
/dev/sda2 / xfs defaults 0 1
none            /dev/pts      devpts    defaults        0   0
dev:~#



Now a second problem may raise ,while connecting to the guest using SSH with silly messages:
time went backwards

Sounds to be a clocksource related problem...

The solution is :
-> add the following extra parameters line to the guest configuration file

extra = 'xencons=tty clocksource=jiffies'

-> set it on the Linux guess using
echo jiffies > /sys/devices/system/clocksource/clocksource0/current_clocksource

Now everything should work perfectly...

For an easier automation of all this stuff I recommend if you use the xen-tools package to add something like this (see the image above) into your /etc/xen-tools/xen-tools.conf configuration file.
In this file you can add a list of packages to the .deb to be installed at each launching of the xen-create-image binary.

Happy coding
Jerome

Tricky problem of connections delivery on Oracle/AIX 5.3

2008-12-17T05:06:00.000-08:00

Hi all,
On a platform with the following characteristics:

AIX 5.3

Oracle 10.0.2.0.3

JDBC thin driver for this exact release ...

I spent 3 days on a tricky problem with an Oracle server delivering connections
after several minutes of inactivity (getting 4 physical connections was a matter of 2 to 3 minutes!!) on a very efficient machine with no apparent system load...
After an in depth look at the Oracle traces (using the support level = level 16) explaining us that
taht my connections induced about 30s pauses before Oracle server decide to give a new physical connection returned ... So there was a network problem ....My code was not responsible at all, but how to deal with such problem?
Decided to reproduce the problem and used my laptop to create virtual images of one Java client and one Oracle server, using the same JDK (1.5) and the same Oracle release on Debian Linux virtual boxes...
My tests were sufficient to see that IPV6 stacks added a lot of level complexity and resulted in having abnormal connection times,even if I was very far 30s/connection... This problem disappeared when I configured the JVM to use the IPV4 stack only!!!
So this morning ,back to customers site, we changed the networking stack of the AIX server and connections are delivered very quickly.....

I was quite happy to use once again free software to demonstrate problems in ..proprietary ones, with 2 of the most famous products: AIX IBM OS and Oracle back end...

Happy coding
Jerome

Testing Web Services : the easy way

2008-12-16T06:12:00.000-08:00

Hi all,
While coding web services with JAX-WS 2.0 and a good IDE (Netbeans rocks of course) is just
a matter of a few clicks, testing them is a little bit trickier... Netbeans (or Elipse) provide JSP pages for testing them on the local application server (Glassfish of course) but how to test the freshly deployed component on your big production server?
Coding a pure Java client is one way, but it hides all the SOAP mesenging stuff and is not always the good way... So I tried to use a more standard and lightweigth solution. My machine (at customers site) is a desktop running Windows XP but with enough memory to enable me to launch a more friendly environment, so I decided to run through VirtualBox a Debian Etch image.
Then after configuring zsh, aptitude, and pretty desktop powered by XFCE, I remember that I used several years ago a tool called curl.
After a little googling in found with this tool the clever and smart solution to test my Web Services,
creating with a single command line a context similar to the one from a delphi client application.

curl -d @soap-message.xml -H "Content-Type: text/xml;charset=UTF-8" \
http://:8080//?WSDL

and that's it...

The file soap-message.xml contains one SOAP message with the test request to be sent.
This file is just a copy/paste from the result of one invocation made through the test page of Netbeans...

I love simple & standard solution...

Hapy coding

Jerome

Obtaining connections on Oracle

2008-12-16T04:24:00.000-08:00

Hi all,
even the simplest thing may become a nightmare.... No this sentence does not comme from
the J.R Tolkien and its best seller Lord of the Rings....But obtaining a JDBC connection is just
a matter from invoking the getConnection() method on DriverManager class, yes...
But where my current problem is tricky is when this code works or not whether some dark aspects. It seems that depending on the database load, on this IBM Aix machine, with a 10.0.2.0.3 Oracle instance, the system generate core dumps then require seconds and seconds to deliver a connection or failing!!! Last week getting 4 JDBC connections at the beginning of a Web Service method induced a 4 minutes delay!!! Rest of the Java code ran for just 37ms!!!
In such context, updating the driver or patching the database are the only solutions...I'll change the driver and pray !

Happy coding
Jerome

PS:
Oracle is quite confusing and requires to have a JDBC driver version matching exactly the server release.... Very constraing...

Xen 3.2 on Debian Lenny

2008-11-20T08:08:00.000-08:00

Hi all,
after several weeks of unfortune, luck is back and I can now run virtual machines on my favorite
Linux distribution. Very nice..During several weeks, my virtual machines were invisible after a few seconds following the boot.It was a dirty parameter ,referenced and documented in the Xen docs but I missed it for a while.Thanks to Patrick Dos Rios for pointing out the problem...
I think I'll post a complete xen installation soon...
Cheers
Jerome

Backups :: Rsync to the rescue

2008-06-29T05:04:00.000-07:00

Hi all,
backing up machines is one the most important things and it's one most
often forgotten . So after many years without a real backup politic, I'd like to setup a real backup server.
As an Unix enthusiast, I decided to put in place a rsync server on this dedicated machine.
Here 's a schema with the goal of this installation:

As suggested my server at home will be used as a repository of backups for different machines (my laptop and the server hosting my product).

Adding other repositories will be just a matter of a few seconds as stated in the section dealing with rsyn configuration on the server side (that is to say for my server at home).

I . File server details
For getting a fast, reliable and huge capacity (volume of stored data in bytes) I 'll setup a software (linux powered) RAID 5 volume with 5 disks of 750 Gb... This to say 3To of usable data , hummm good enough for 500€ and reusing a not so old unused machine!!! (5 Hitachi disks at 105€ each)

Rsync is setup with just adding the package to the Debian using aptitude:
aptitude install rsync and that's it!!!

Just modify the /etc/default/rsync to enable launching rsync as a daemon!!!

Then creating a /etc/rsyncd.conf file with the different modules (module=one of the different place to save).
The configuration looks like this:

uid = rsync
gid = rsync
log file=/var/log/rsyncd.log
[backup_laptop]
path = /home/backup/laptop
comment = Synchro fichiers laptop
read only = false

here I tell rsync to use rsync username/group identity and to log data into the conventional place /var/log.
Here 's a test file with just one module used to host data incoming from my laptop.
Quite easy isn't it ? -)

Adding user/group is just a matter of :
useradd rsync //to add the user
the groupadd command to add rsync to the group rsync

then chown -R rsync:rsync
then chmod -R 700

And finally start the rsync server with the usual /etc/init.d/rsync start command

We may make so refinements after getting all this stuff running,while allowing rsync to listen on the single loopback pseudo ethernet device (127.0.0.1)....

Most of the configuration from the client side is done!!!

II. Client side

No special setup required on the client side , just ensure to have the rsync binary (aptitude install rsync).

Launching a file synchronization is just a matter of running the following command:

>rsync -avz ~/ 192.168.10.33::laptop_backup

Here notice:
- options avz to preserve rights/owner (archive mode)
- syntax server::module_name, here remember the module name as defined on the server side

SSH is used to transport data over the network (LAN in this case)...

All this stuff works because I created a special RSA key on the server machine and imported this key(private one) into the client authorized keys directory (through scp).

You can also notice that I don't want to use the common --delete flag , because this flag enable rsync to suppress things from backup machines, if deleted from the master one...I don't want a perfect mirror, I prefer to waste a little disk space rather than loosing data!!!!

III. Final touch

What must be done yet ? A few things :
- automating backups !!!
In my case cron is useless, because I 'm not very often at home without any good shcedule time/date..So if I've got enough time I'd like to setup a very special
configuration using /etc/network/interfaces mechanism to detect if my laptop is at home or not and to add a hook running the explicit synchronization...
Don't know if it's even possible, but I'll try to follow this idea...

- modifiy the RSA private key to restrict rights/usage to enforce security

- change the rsync daemon setup to use the only loopback interface because it 's just run by the SSH tunnel and never invoke directly.So avoiding to expose such thing is a good thing even if security is not my first priority!!!!

- manage incremental backups to avoid huge transfers accross the network and gain CPU usage
That's all folks
Enjoy

Jerome

Welcome in a virtual world

2008-05-24T07:34:00.000-07:00

Hi all,
juste a few words about my current concerns...
I needed for a customer of mine to setup a special configuration dealing with HA and reliability of messages using the OpenMQ JMS implementation from Glassfish...
So I decided to use virtualization technologies to avoid to use many machines!!!
I need to have 2 (or more) openmq instances sharing a database (running in other machine)
so using VirtualBox wonderful product I setup private networking in my host OS with 3 virtual machines all using a debian 4.0r3 Linux distribution..
I don't need graphical UI for these servers so debian netinstall iso image is sufficient...
All other softwares come from one directory (shared using SSH server running on my guest OS)...
This works great, I can ping among machines in the private network, access Internet through the host OS (but host OS can 't access me).
Now after many days spent in choosing the right virtualization technique, I can work in a secured, stand-alone, isolated, envrionment...Great

Happy coding
Jerome

Disabling TCP v6 on a linux machine

2008-03-31T15:01:00.000-07:00

Hi all,
after several searches on google, I succeeded in finding the place to configure TCP v4 only on my Debian Etch.
Simply set the net10-pf to off in /etc/mobprobe.d/aliases, reboot and that's it...
Now daemons run without TCP 6 layer....

Enjoy
Jerome

I love SWT!!!!!

2007-11-15T03:49:00.000-08:00

Hi all,
this is a small comment about this wonderful technology : SWT. While working on a huge project in Switzerland using Eclipse/RCP as the basis for GUI building, it 's for me an opportunity to use SWT/JFace once again (did'nt play with them for 3 or 4 years).
In the same time, it's an opportunity to play with recent Eclipse versions (3.2.2).
My first feelings are not very positive:
* Eclipse is totally unstable, one small plugin can break your pretty configuration
* SWT has many limitations and many bugs
we are still unable to open applets within a browser from an RCP application using the SWT browser widget
playing with the sexy version of the old Runtime.exec() method called Program class in SWT, in found ridiculous behaviors:
don't handle arguments on the command line properly
can't find one binary Program.find("iexplore.exe") doesn't return on my machine (may be a little strange I agree)

SWT basic widgets are still very low level while JFace (layer bringing a little bit of abstraction and a MVC based design) is still too small (not many widgets available).
SWt events are still mysterious for me andd the documentation is still too weak...-(

I 'm still disapointed with this project so sexy but which doesn't work at the end...
I'm using netbeans or vi depending from the amount of code to be done and I'm still convinced that they are far more efficient tools than Eclipse...
(netBeans 6.0 is quite ready and it's full of nice features)

See you soon on the JavaSphere

I hate hardware!!!

2007-06-16T10:24:00.000-07:00

Hi,
just a few words to exhibit my feelings about hardware...
A few monthes I had 3 machines : one Linux server, one windows machine (for games) and one solaris desktop machine (for Java stuff)..; All these machines in the same LAN behind a router/firewall and sharing the same keyboard/monitor using an excellent BELKIN KVM (VGA/PS2)...Then my old 19" IIyama monitor died (just the alimentation cable) so I decided to buy a fresh 22" LCD monitor (SAMSUNG)... this was beginning of troubles, using this kind of monitor implies to use a new KVM, so I bought a new KVM from Belkin (Soho Series USB/DVI) and I just spent one week buying keboards, connecting machines to see that this product called a KVM had a very impressive features list:
* unable to support 2 machines on the same time without using the VGA cable and bypassing the KVM (no synchronization of video possible)
* unable to map all keyboard keys (<> characters ?

So I hate hardware !!! it's just a lack of time and I dream for the provider of virtualized systems enabling to put its emphase on serious problems rather than being focused on cabels and other stuff!!!

happy coding
jerome

Emacs and XSD schema edition

2007-06-16T10:19:00.000-07:00

Hi,
I love Unix and many Unix tools, one of these is the fabulous Emacs editor, far superior to any other editor (troll -) ) ... I'm a little bit confused because if XML editing is very nice using the nxml-mode , XSD editing seems not supported (there's only one small mode rnc-mode for ediing Relax NG documents with the RNC syntax)... It's a shame because using RNC is not in my roadmap and converting XSD to RNC (and the opposite) is not a very good option for me...
Don't know what to do....

Happy coding
Jerome

First steps with Ruby/STOMP and activemq

2007-05-22T15:57:00.000-07:00

Hi,
I'm a quite old user from ActiveMQ, but my last experience with this wonderful JMS server deals with STOMP ? What's this beast ? It's a protocol enabling JMS message sending/receiving from scripting languages like Ruby, PERL or Python... This protocol is very lightweight and powerful enough to bring the JMS world to these technologies...
I decided to test with Ruby, seems to be a wonderfull language, easy, intuitive and very powerful...
Using STOMP protocol is very easy , just install with the GEM installer, the STOMP package (module for Ruby experts)..
gem install stomp and that's it....
in fact getting gem was the most difficult thing for me, because I was unable yto get it working on my Solaris 11 box, but apt-get saved me and installation is as easy as : aptitude install gem on my Ubuntu server...

STOMP is fast, Ruby too, scripts are about 10 lines and ActiveMQ is shipped with a STOMp connector so let's play with it...

Happy coding
Jerome

I love zsh -)

2007-05-17T14:25:00.000-07:00

Hi,
another small message, diving into Solaris 10 (OpenSolaris) using b55 & b63, I discovered a shell
zsh...Another one, I said, since the day where I fetched some .zshrc files, then launched this shell from my old bash... I think I won't return to bash.. Zsh is so powerfull... Command line completion is far superior to the one from bash (even using bash completion package)...
So this is my .zshrc file, I hope it could convince you to switch to this fantastic piece of software...
Like any other .rc file, this is a work in progress, but should be usable in a few minutes (just set the PATh/MANPATh according to your system)..

This is the screenshot from an empty terminal with a very powerful prompt...
happy coding & enjoy zsh

Cheers
jerome

# .zshrc from J.MOLIERE
# jerome@javaxpert.com
# jerome.moliere@gmail.com
#using many .rc files !!!!

#defines PATH
export JAVA_HOME=
export ANT_HOME=
export MAVEN_HOME=
export PATH=/usr/local/bin:/usr/sfw/bin:/opt/sfw/bin/:/opt/sfw/teTeX/bin/i386-pc-solaris2.10/:$PATH

export MANPATH=/usr/sfw/share/man:/usr/local/man:$MANPATH
#zsh completion style
zstyle ':completion:*:*:*:*:processes' menu yes select
zstyle ':completion:*:*:*:*:processes' force-list always
zstyle ':completion:*' use-cache on
zstyle ':completion:*' cache-path ~/.zsh/cache
# ignore CVS & SVN files
zstyle ':completion:*:(all-|)files' ignored-patterns '(|*/)CVS'
zstyle ':completion:*:cd:*' ignored-patterns '(*/)#CVS'
zstyle ':completion:*:(all-|)files' ignored-patterns '(|*/)SVN'
zstyle ':completion:*:cd:*' ignored-patterns '(*/)#SVN'
#skip absent binaries
zstyle ':completion:*:functions' ignored-patterns '_*'

zstyle ':completion:*:*:kill:*' menu yes select
zstyle ':completion:*:kill:*' force-list always

zstyle ':completion:*' squeeze-slashes true

# completion
compctl -g '*.java' + -g '*(-/)' javac
compctl -g '*.gz' + -g '*(-/)' gunzip gzcat
compctl -g '*(-*)' + -g '*(-/)' strip
compctl -g '*.ps *.eps' + -g '*(-/)' gs ghostview psnup psduplex ps2ascii
compctl -g '*.dvi' + -g '*(-/)' xdvi dvips
compctl -g '*.xpm *.xpm.gz' + -g '*(-/)' xpmroot sxpm pixmap xpmtoppm
compctl -g '*.fig' + -g '*(-/)' xfig
compctl -g '*(-/) .*(-/)' cd
compctl -g '(^(*.o|*.class|*.jar|*.gz|*.gif|*.a|*.Z))' more less vi
compctl -g '*.ps *.pdf' + -g '*(-/)' evince
compctl -g '*.pdf' + -g '*(-/)' xpdf
compctl -g '*.bz2 *.bz' + -g '*(-/)' bunzip2
compctl -g '*.tex' + -g '*(-/)' pdflatex

myclasslist () { reply=(${$(ls *.class)%.class}) }
compctl -K myclasslist java

#PROMPT & RPROMPT
#PROMPT=$(echo '%{\033[31m%}%m>%{\033[30m%}')
#RPROMPT=$(echo '%{\033[32m%}%~%{\033[30m%}')
function precmd {

local TERMWIDTH
(( TERMWIDTH = ${COLUMNS} - 1 ))

###
# Truncate the path if it's too long.

PR_FILLBAR=""
PR_PWDLEN=""

local promptsize=${#${(%):---(%n@%m:%l)---()--}}
local pwdsize=${#${(%):-%~}}

if [[ "$promptsize + $pwdsize" -gt $TERMWIDTH ]]; then
((PR_PWDLEN=$TERMWIDTH - $promptsize))
else
PR_FILLBAR="\${(l.(($TERMWIDTH - ($promptsize + $pwdsize)))..${PR_HBAR}.)}"
fi

###
# Get APM info.

if which ibam > /dev/null; then
PR_APM_RESULT=`ibam --percentbattery`
elif which apm > /dev/null; then
PR_APM_RESULT=`apm`
fi
}

setopt extended_glob
preexec () {
if [[ "$TERM" == "screen" ]]; then
local CMD=${1[(wr)^(*=*|sudo|-*)]}
echo -n "\ek$CMD\e\\"
fi
}

setprompt () {
###
# Need this so the prompt will work.

setopt prompt_subst

###
# See if we can use colors.

autoload colors zsh/terminfo
if [[ "$terminfo[colors]" -ge 8 ]]; then
colors
fi
for color in RED GREEN YELLOW BLUE MAGENTA CYAN WHITE; do
eval PR_$color='%{$terminfo[bold]$fg[${(L)color}]%}'
eval PR_LIGHT_$color='%{$fg[${(L)color}]%}'
(( count = $count + 1 ))
done
PR_NO_COLOUR="%{$terminfo[sgr0]%}"

###
# See if we can use extended characters to look nicer.

typeset -A altchar
set -A altchar ${(s..)terminfo[acsc]}
PR_SET_CHARSET="%{$terminfo[enacs]%}"
PR_SHIFT_IN="%{$terminfo[smacs]%}"
PR_SHIFT_OUT="%{$terminfo[rmacs]%}"
PR_HBAR=${altchar[q]:--}
PR_ULCORNER=${altchar[l]:--}
PR_LLCORNER=${altchar[m]:--}
PR_LRCORNER=${altchar[j]:--}
PR_URCORNER=${altchar[k]:--}

###
# Decide if we need to set titlebar text.

case $TERM in
xterm*)
PR_TITLEBAR=$'%{\e]0;%(!.-=*[ROOT]*=- | .)%n@%m:%~ | ${COLUMNS}x${LINES} | %y\a%}'
;;
screen)
PR_TITLEBAR=$'%{\e_screen \005 (\005t) | %(!.-=[ROOT]=- | .)%n@%m:%~ | ${COLUMNS}x${LINES} | %y\e\\%}'
;;
*)
PR_TITLEBAR=''
;;
esac

###
# Decide whether to set a screen title
if [[ "$TERM" == "screen" ]]; then
PR_STITLE=$'%{\ekzsh\e\\%}'
else
PR_STITLE=''
fi

###
# APM detection

if which ibam > /dev/null; then
PR_APM='$PR_RED${${PR_APM_RESULT[(f)1]}[(w)-2]}%%(${${PR_APM_RESULT[(f)3]}[(w)-1]})$PR_LIGHT_BLUE:'
elif which apm > /dev/null; then
PR_APM='$PR_RED${PR_APM_RESULT[(w)5,(w)6]/\% /%%}$PR_LIGHT_BLUE:'
else
PR_APM=''
fi

###
# Finally, the prompt.

PROMPT='$PR_SET_CHARSET$PR_STITLE${(e)PR_TITLEBAR}\
$PR_CYAN$PR_SHIFT_IN$PR_ULCORNER$PR_BLUE$PR_HBAR$PR_SHIFT_OUT(\
$PR_GREEN%(!.%SROOT%s.%n)$PR_GREEN@%m:%l\
$PR_BLUE)$PR_SHIFT_IN$PR_HBAR$PR_CYAN$PR_HBAR${(e)PR_FILLBAR}$PR_BLUE$PR_HBAR$PR_SHIFT_OUT(\
$PR_MAGENTA%$PR_PWDLEN<...<%~%<<\ $PR_BLUE)$PR_SHIFT_IN$PR_HBAR$PR_CYAN$PR_URCORNER$PR_SHIFT_OUT\ $PR_CYAN$PR_SHIFT_IN$PR_LLCORNER$PR_BLUE$PR_HBAR$PR_SHIFT_OUT(\ %(?..$PR_LIGHT_RED%?$PR_BLUE:)\ ${(e)PR_APM}$PR_YELLOW%D{%H:%M}\ $PR_LIGHT_BLUE:%(!.$PR_RED.$PR_WHITE)%#$PR_BLUE)$PR_SHIFT_IN$PR_HBAR$PR_SHIFT_OUT\ $PR_CYAN$PR_SHIFT_IN$PR_HBAR$PR_SHIFT_OUT\ $PR_NO_COLOUR ' RPROMPT=' $PR_CYAN$PR_SHIFT_IN$PR_HBAR$PR_BLUE$PR_HBAR$PR_SHIFT_OUT\ ($PR_YELLOW%D{%a,%b%d}$PR_BLUE)$PR_SHIFT_IN$PR_HBAR$PR_CYAN$PR_LRCORNER$PR_SHIFT_OUT$PR_NO_COLOUR' PS2='$PR_CYAN$PR_SHIFT_IN$PR_HBAR$PR_SHIFT_OUT\ $PR_BLUE$PR_SHIFT_IN$PR_HBAR$PR_SHIFT_OUT(\ $PR_LIGHT_GREEN%_$PR_BLUE)$PR_SHIFT_IN$PR_HBAR$PR_SHIFT_OUT\ $PR_CYAN$PR_SHIFT_IN$PR_HBAR$PR_SHIFT_OUT$PR_NO_COLOUR ' } setprompt # GLOBAL ALIASES & SUFFIXES ALIASES alias -s tex=emacs alias -s html=firefox alias -s org=firefox alias -g ...='../..' alias -g ....='../../..' alias -g .....='../../../..' alias -g CA="2>&1 | cat -A"
alias -g C='| wc -l'
alias -g D="DISPLAY=:0.0"
alias -g DN=/dev/null
alias -g ED="export DISPLAY=:0.0"
alias -g EG='|& egrep'
alias -g EH='|& head'
alias -g EL='|& less'
alias -g ELS='|& less -S'
alias -g ETL='|& tail -20'
alias -g ET='|& tail'
alias -g F=' | fmt -'
alias -g G='| egrep'
alias -g H='| head'
alias -g HL='|& head -20'
alias -g Sk="*~(*.bz2|*.gz|*.tgz|*.zip|*.z)"
alias -g LL="2>&1 | less"
alias -g L="| less"
alias -g LS='| less -S'
alias -g MM='| most'
alias -g M='| more'
alias -g NE="2> /dev/null"
alias -g NS='| sort -n'
alias -g NUL="> /dev/null 2>&1"
alias -g PIPE='|'
alias -g R=' > /c/aaa/tee.txt '
alias -g RNS='| sort -nr'
alias -g S='| sort'
alias -g TL='| tail -20'
alias -g T='| tail'
alias -g US='| sort -u'
alias -g VM=/var/log/messages
alias -g X0G='| xargs -0 egrep'
alias -g X0='| xargs -0'
alias -g XG='| xargs egrep'

alias vi='vim'
alias more='less'

First steps into the Terracotta world!!

2007-05-17T02:27:00.000-07:00

Hi,
a few words during this vacation day in France to deal with a hot subject : clustering technology.
I 've made a small demo program for my customers (Reuters Financial Services) of the Open Terracotta transparent clustering features using their DSO facilities. Very impressive: works well, not intrusive, configuration easy, seems very stable and mature for a so young product. Only bemol in this beautiful picture, documentation is quite confusing and many features are not yet implemented but just wait...
I used a simple Map implementation to keep my data as a distributed cache, now Terracotta does not support all implementations of the java.util.Map interface so I used the Jakarta Commons FastHashMap which is supported through an enhanced version of the original bytecode... Didn't succeed in providing my own version of the java.util.HashMap or other Map implementation from the Sun packages...Terrocotta provides a small script to enhance the rt.jar but it did'nt work (script succeeded in but could not use these implementations). It's a very young product but functional and very fast even if I didn't have enough time to set up a solid benchmark...
Conclusion:
I 'm totally convinced this is the major innovation in the Java World since many years and that this technology is about becoming the core of any serious architecture... Just test it!!!
I will put on this blog, a small tarball containing the demo as it...
Jerome

Java and dual IP stacks machines

2007-04-04T03:40:00.000-07:00

Hi,
just for people stressed by non working J2EE clusters or unable to connect remotely to their JMX console...
Certain recent Linux distributions provide a support for IP v4 and V6 on the same box.. This support is quite annoying while using Java code and the best solution is to remove one of the 2 stacks from the Java Virtual Machine point of view...
Java guys from Sun know the problem and provide a clean solution with another (hidden?) property java.net.preferIPv4Stack=true
Setting this property to the java program with a -D on the command line and your application is ready to communicate ....

Hope this helps
Jerome

Cayenne and Sybase

2007-04-04T03:20:00.000-07:00

Hi ,
while playing with Cayenne ORM solution, I encountered strange problems with Sybase 12.5.4. Commit never run for updates , applications hangs...
Sounds to appear in the low level JDBC layers.. But don't have enough time to debug...
Cayenne team members seem to have the same problems....
Jerome

Subversion on debian like boxes: a quick howto

2007-02-11T02:33:00.000-08:00

Hi all,
this post aims to ease your next installations of subversion (cvs killer!!) on Linux (should be usable with different Unix systems). This short how-to will use the xinetd based daemon and not the Apache module... I prefer this kind of installation...It's quick and clean, sufficient for a small system... So this small how-to will use the svnserve binary..

I. Getting binaries and installing them
On debian like systems this step is very simple, just do an
apt-get install subversion
or aptitude install subversion and that's it!!

On most Ubuntu boxes these commands require to be done with a sudo command (require root privileges)
so
sudo aptitude install subversion should do the job...

Ports on bsd Unixes should be quite similar or packages on Solaris (don't know all Unixes)..
For Redhat based Linux distros use the rpm or urpmi binary...

II. Prepare the system
Basic Unix security require to use root privileges as least as possible so subversion daemon will run as the svn user with the svn group..
Adding the svn group is quite easy:
sudo addgroup svn
Adding an user on a Unix system should be done with the adduser command.. I don't want that someone log on my box with the svn profile so I will disable the home and password for this account...

sudo adduser svn --no-create-home --system --in-group svn svn

So I 've got an user svn linked with the svn group...

Next ensure that your system use a xinetd super daemon to launch subversion..
Once again aptitude or apt-get is your friend...

sudo aptitude install xinetd

Now we must add a service into the xinetd daemon for launching subversion..

ensure that your /etc/services contains the right information (subversion use the IANA port : 3690 by default)
adds the service definition in the /etc/xinetd.d/ directory
ensures that your xinetd configuration file (/etc/xinetd.conf) contains instructions required to load all services defined in the /etc/xinetd.d/ directory.

romje@buggy:~$ cat /etc/services |grep 3690
svn 3690/tcp subversion # Subversion protocol
svn 3690/udp subversion
romje@buggy:~$

Please beware to use the name of service (svn) as the service file and name to be added in your xinetd.conf file...On my box default name was subversion...

romje@buggy:~$ cat /etc/xinetd.conf
# Simple configuration file for xinetd
#
# Some defaults, and include /etc/xinetd.d/

defaults
{

# Please note that you need a log_type line to be able to use log_on_success
# and log_on_failure. The default is the following :
# log_type = SYSLOG daemon info
log_on_failure = HOST
nstances=80
log_type = SYSLOG authpriv
log_on_success = HOST PID
cps = 30 40
}

includedir /etc/xinetd.d

This configuration is usable for a small server not for large companies...

Now let's look the subversion definition (/etc/xinetd.d/svn)

romje@buggy:~$ cat /etc/xinetd.d/svn
service svn
{
socket_type = stream
protocol = tcp
user = svn
wait = no
disable = no
server = /usr/bin/svnserve
server_args = -i --root=/pub/svn
port = 3690
}

This configuration tells to serve contents stored in the /pub/svn directory (use whatever location on your machine) while running as a daemon (-i flag)...

Restarting the xinetd daemon should show in /var/log/syslog file...
Feb 11 12:15:14 buggy xinetd[9657]: xinetd Version 2.3.14 started with libwrap loadavg options compiled in.
Feb 11 12:15:14 buggy xinetd[9657]: Started working: 1 available service

While netstat and telnet tell you that something listen on the 3690!!!
romje@buggy:~$ sudo netstat -anp |grep 3690
tcp 0 0 0.0.0.0:3690 0.0.0.0:* LISTEN 9657/xinetd

romje@buggy:~$ telnet localhost 3690
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
( success ( 1 2 ( ANONYMOUS ) ( edit-pipeline ) ) )

Ok seems good...
Let's look how to add a repository into svn..

III. Creating repositories with svn
Creating a repository is quite easy...
romje@buggy:~$ sudo svnadmin create /pub/svn/test test
romje@buggy:~$ ls /pub/svn/test
conf dav db format hooks locks README.txt
romje@buggy:~$

Now will use the basic authentication schemes to protect our repository:
Let's have a look into the conf directory in the /pub/svn/test newly created you'll find a svnserve.conf file, it tells how-to manage security to the svnserve program.
### These options control access to the repository for unauthenticated
### and authenticated users. Valid values are "write", "read",
### and "none". The sample settings below are the defaults.
anon-access = none
# auth-access = write
### The password-db option controls the location of the password
### database file. Unless you specify a path starting with a /,
### the file's location is relative to the conf directory.
### Uncomment the line below to use the default password file.
password-db = users.dat

In this case a simple properties file in the same directory stores users enabled for this directory..
[users]
toto = totopassword
foo = baz

This could enable 2 users to connect to the repository test..

Now happy svn co svn://yourhost/test!!!

IV. Last step
Now open your firewall and redirect the 3690 port to the subversion server and you are ready to serve files...

Enjoy
cheers
Jerome

Hibernate or any other ORM tool?

2006-11-08T03:16:00.000-08:00

Hi all,
the question of day ? How mature are Hibernate or any other ORM(object relational ampping tool) ? In fact while reading the code it's nice isn't it ? Transparent persistence and so on ... But for my point of view it seems that all these presume that your IT system doesn't exist ... Dealing with stored procedures is not so easy, managing transactions levels or disabling triggers is tricky, mapping for inheritance has some big limits, no versioning integrated in these tools...
My feeling is that these products are mature but that they could not find the exact list of features that professional could require, they make too many things and too few in the same time....
I remember the excellent link
frameworkitis ? -)

friendly
Jerome

Technical books: poor or not ?

2006-11-07T05:00:00.000-08:00

Hi all,
2 posts in the same day !!
I've read many technical books and I find that many of them are too poor, don't provide many industrial feedbacks and don't go in depth into the internals of the products, am I alone ?
I'm quite angry against latest O'Reilly Java related books, which are just gentle introductions with simplistic samples. Example given : Hibernate , I 'm unable to find a complete sequence diagrams with all components involved while doing a typical save() or update()on my POJO ?
Where the physical transaction begins, where(and how) hibernate instruments my bytecode , all these questions are crucial for any serious developper or architect and I can't find answers ? Playing with libraries or kittens just sucks!!

I think I'll be obliged to make this work ...
friendly
Jerome

Back on the blogosphere- II the return

2006-11-07T04:51:00.000-08:00

Hi,
too many things to do to find enough time to write here daily!!!
I 'm trying to help customers to choose an ORM solution in Java, everybody think about Hibernate but I 'm not totally convinced...Trying and benching is necessary before telling : that 's the solution!! But this method pushes me in dire straits, how to use benchmarks while many of them are very partial documents published directly by software vendors or directly sponsored? I think that industrial software needs infrastructure offering a way to run tests , to collect results and so on..
Something like a Junit but dedicated to performance ...
One more project in my bag, this one seems to be about exploding !!!

enjoy your cup of Java!!
friendly
Jerome

Back on the blog

2006-03-16T07:38:00.000-08:00

After a while without posting my humor, I will take a moment to talk about the latest silver bullet:AJAX ... Have you ever seen any AJAX application ? looks nice isn't it ? Too simple to be honnest : simple to deploy with standard protocols (nothing more than HTTP), simple to integrate in your project, very conveniant & economic (for your bandwidth). SO what 's wrong with AJAX?

Nothing more than the crual truth: Javascript is a nightmare!!!
Have'nt you seen webpages unusable on Mozilla ? Or stopping to work after an upgrade from IE Y.X to Z version ? :)
Yes the huge problem with AJAX is that there's no common Javascript component used in all browsers (Rhino or any Ecma script compliant one). So your wonderfull application with cool refresh features will be simply unusable on many browsers...

Silver bullet yes, but choose your vampires..

See you soon
Jerome

ANT or Maven: that is the question...

2005-11-17T07:46:00.000-08:00

Hi all,
playing around with ANt & many custom tasks I returned to the eternal question:
ANT or Maven ? What could bring me Maven ?
Reusing scripts is possible (one of the greatest new feature in ANT 1.6) so what ?
Once these metahycial considerations done, i can return play with my ipod, nice gadget isn't it ?

Jerome

Blog still alive

2005-11-16T07:35:00.000-08:00

Hi,
very hard for me to have enough time to feed my blog but I guess it's like sport or
any other other form of exercise...:)
While diving into the heart of Spring I can't bear thinking of these tons of good ideas evoluting in a bad direction.. Please don't make the error that Maven team or many other projects, keep it as simple as possible :)

that's enough for this day

Sheets ?

2005-07-01T06:08:00.000-07:00

Hi,
as a french guy I'm not sure of the spelling of this word but it sucks while playing with docbook documents to encounter problems
with XSLT transformations. It seems that Xalan embedded in JDK 1.5_up3 is far from being usable, because the same document on the same machine is converted into PDF with FOP with Saxon or JDK 1.4.2 with Xalan embedded . So once again you may stress for nothing...

Jerome

To be or not to be?

2005-06-30T02:08:00.000-07:00

Hi,
choice is the better thing bringing freedom for us to build fast/secure/robust platforms...But how to handle choice ?
For example Hibernate is fun, simple & powerful but seems to be slow (made some tests with the default cache EHCACHE & recovering cached data for simple SQL requests is just 2 times faster than making the request with JDBC)..I think that the opnly way to handle choice is to get some strong practices (methodology) & to be able to plan some real test cases.
That is to say real life projects should offer not only R&D but effective period to manage the choice dilemna!!
Never saw a silver bullet, so our decisions must be made in a context as closer as possible from the one defining your applications.
Do you really encountered such periods in your plannings ?
So who could be surprised by the number of projects failing to adhere to the initial roadmap ?

But life is life..
Jeroem

Initial Post

2005-06-29T10:37:00.000-07:00

Hi all,
hard to make the first step isn't it ? :)
So you'll be able to share my thoughts for the next days...
I'm very sad to see that even my old friend LOg4J can play with my nerves..I hope to see my events in the syslog daemon soon...

See you soon & take care
Jerome