Arnaud Simon's WebLog

GC tuning

2010-12-03T09:27:00.000-08:00

Good article about GC tuning:

http://www.oracle.com/technetwork/java/gc-tuning-5-138395.html#0.0.0.When%20to%20Use%20the%20Throughput%20Collector|outline

JAVA opts to get the gc dat : JAVA_OPTS="$JAVA_OPTS -XX:+UseConcMarkSweepGC -verbose:gc -XX:+PrintGCTimeStamps -XX:+PrintGCDetails -Xloggc:/root/gc.log"

Mono on RHEL5

2008-10-15T06:23:00.000-07:00

Install Mono on RHEL5

Create the file "/etc/yum.repos.d/mono.repo" and add the following lines:

[Mono]
name=Mono Stack (RHEL_5)
type=rpm-md
baseurl=http://download.opensuse.org/repositories/Mono/RHEL_5/
gpgcheck=1
gpgkey=http://download.opensuse.org/repositories/Mono/RHEL_5/repodata/repomd.xml.key
enabled=1

Enter the following command to install Mono:

# yum install mono-complete

SOA Symposium

2008-08-13T00:24:00.000-07:00

I'll be talking at the first international SOA Symposium in Amsterdam (October 7-8 2008).
Mark,
Jim
and Thomas will be around!

AMQP distributed transaction support

2007-04-24T00:02:00.000-07:00

I have added material on the AMQ transaction SIG wiki pages regarding distributed transaction support.

The proposal has been approved by AMQP PMC and will therefore be added in the next version of the specifications.

Transactional metaphore

2007-04-23T23:55:00.000-07:00

I just read this quote on Mark’s blog “Transactions and cars”. I really think that Mark has found a fantastic metaphor for explaining why transactions and recovery are important.

I have joined Red Hat

2007-03-05T05:25:00.000-08:00

I haven't blogged for ages but things have changed quickly. I have recently joined Red Hat as principal software engineer. I have joined the AMQP/Qpid team with a prior focus on distributed transactions. This is a young and motivated team. I am currently working remote but I should join the main part of team in Boston sooner or later.

Le Touquet

2006-08-23T05:52:00.000-07:00

I am just back from “Le Touquet”.
This is a great holiday resort that I highly recommend if you love vast sandy beaches.

On Bullshit

2006-08-23T05:40:00.000-07:00

A colleague of mine recently sent me this link: On Bullshit
I just ordered the book as it looks very interesting especially to better understand how all those consultant work :)
I’ll let you know soon if the book is worth a look at but it looks as if it will be good fun.

A chat with Mark Little

2006-07-26T07:51:00.000-07:00

A very interesting interview of Mark Little. Jboss will come on the ESB market earlier than expected.

SOA and AJAX

2006-07-12T23:59:00.000-07:00

There is a good paper about SOA and AJAX in the latest “SAO Web Services“ (pare 48).

I find the analysis of user expectations quite realistic.

XAP

2006-06-20T23:11:00.000-07:00

Nexaweb Technologies Inc has donated its technology to Apache. XAP is an XML-based declarative framework for building, deploying and maintaining rich, interactive Ajax powered web applications.

I am not sure about this technology but as this is now an Apache product I'll watch it.

SOA quotes

2006-06-14T06:00:00.000-07:00

Here are few SOA quotes that my friend Thomas sent me a while ago:

• SOA development is a lot like teenage rebellion. There's a wide gap between the number of people talking about it and the number who are actually doing it.

• Ask a developer if he/she is building Web services and the answer almost invariably will be yes. Ask that same person if those services are being registered and the answer almost invariably will be no.

• The best sentence ever written about SOA is still the ZapThink mantra: SOA is not something you buy, it's something you do. Nothing clarifies the concept better.

• When you run into people complaining about SOA, if you talk to them long enough you'll usually find that they agree with all the core principles behind it and their complaint revolves around the name itself and the way it's been marketed.

• The enterprise service bus is going to be completely transformed in the coming years. Not only will ESBs offer business process management and Web services management functionality, but the very nature of messaging will be streamlined. It's the unspoken arms race of the SOA vendor community.

• In Dutch, SOA stands for seksueel overdraagbare aandoenin, which means sexually transmitted disease.

• Much as users like to claim independence, they still look to the vendor community to guide them. If SOA fails to take hold, if users don't ultimately embrace this method of building services, it will be because the vendor community failed to get itself organized around the concept.

SSO

2006-06-08T00:30:00.000-07:00

There is very a good SSO paper on theserverside “SOA and Identity Management” from Justen Stepka.
Definitely a good to read paper.

Web Services Security

2006-05-21T01:37:00.000-07:00

I recently bought Mark O’Neil, et al. “Web Services Security” book that I read on my way back from JavaOne.

This is an excellent book that everybody dealing with SOA MUST read. We too often hear people mixing up SAML and WS-Security (this was my case anyway) and forgetting about XACML and XKMS.

The first part provides a clear WS introduction and reminds, if needed, the basic security concepts: confidentiality, integrity, nonrepudiation, authentication and authorization. All those concepts are very well illustrated with good examples.

The second part of the book is dedicated to XML security; this is a book about Web Services security after all. I found the chapters about SAML, XACML and XKMS very useful. I must recognize that I only had a surface knowledge about SAML and that I did not know anything about XACML and XKMS.

The third part provides more details about WS-Security. Once again this is good to be reminded about the basic standards on which WS-Security relies i.e. WS-Policy, WS-Trust, WS-Privacy, WS-SecureConversation, WS-Federation and WS-Authorization.

The last parts talk about .Net and passports and provide plenty of examples and case studies.

To summarize, this is an excellent book that is easy to read and that should raise IT consultants’ security awareness. I highly recommend it.

One little remark made in the book that I liked very much is that “Web Services” should be named “Net Services”. This is certainly true that Services are not only exposed over the internet. The name “Net Services” would moreover have been less misleading than “Web Services” when it comes to transport. Indeed people too often forget that SOAP is transport agnostic.

Finally this book helped me better understand where authorization policies should be decided and enforced. I now realize that authorization policy enforcement should not be done at the service level but kept outside the service realm.

JavaOne

2006-05-19T18:50:00.000-07:00

Today was my last day at JavaOne. It was an overall very good week.

On the technical side I learned more about the Java Persistence API (JAP) that is the standard API for the management of persistence and object/relational mapping in Java EE 5 platform. JAP should eventually replace JDO.

Service data interaction is also simplified with Service Data Objects SDO. the SDO API lets you work with data from multiple data sources, including relational databases, entity EJB components, XML pages, Web services, etc. SDO also takes care of data change summaries that are used at backend update time to apply the changes back to the data source. This is all cool and better described here and also implemented by this excellent BEA Aqualogic Data Service Platform.

Obviously AJAX was an important theme and I have got the feeling that the trend is to develop Web GUI using AJAX enabled JSF components.

Otherwise, it was also good to get a broad overview of the current product offering. Note that Sonic did not attend JavaOne this year. Hum, I wonder why? This being said, I was not impressed by Fiorano ESB offering.

On the social life side, the JBoss party was excellent and the JavaOne one a bit too big, it is difficult to entertain and feed 14 000 persons.

2006 IEEE SOA Industry Summit

2006-05-07T04:24:00.000-07:00

Thomas and I have our paper, titled "Service Contract Template", that has been accepted for the 2006 IEEE SOA Industry Summit.

We don’t know yet who is going but I hope I’ll manage to go as it is very promising. Moreover, I have never been to Chicago before :)

Infravio and Layer 7 Partnership

2006-04-04T01:08:00.000-07:00

Infravio and Layer 7 Technologies have completed integration between their respective SOA solutions, X-Registry Platform and SecureSpan. This looks very cool. For more info see this link: http://www.adtmag.com/article.aspx?id=18152

Mindreef Coral

2006-03-22T00:29:00.000-08:00

I have recently evaluated Mindreef Coral. Mindreef Coral is a collaboration platform for Web services teams. It is implemented on top of Tomcat and offers a nice Web based GUI. You can visualize WSDL, invoke services, analyze WSI compliance, inspect messages and share workspace (RSS feeds).

It looks very good, I am however skeptical as it is a little bit buggy. Moreover I think that this type of product should only be considered for very large teams. I really think that most of the features are already available by combining eclipse and a wiki or even this nice collaboration online word processor ZOHO.

Running Blog

2006-02-17T05:36:00.000-08:00

I have now a Running blog. The aim is to keep the competition spirit high by staying in touch with my virtual training partners that are located in Spain, Ireland and France.

Garmin Forerunner 301

2006-02-11T09:47:00.000-08:00

I have recently bought a Garmin forerunner 301:

This is an excellent training partner that continuously monitors your heart rate, speed, distance, pace and calories burned! I’ll run the Paris marathon next April and I really though that I need such a little cool device to train smarter and more effectively.

The bundled software is poor but I am now using sportTracks. The following is a picture of my today workout:

SportTracks automatically track the distance, time and pace of your workouts. You are even able to visualize your route with google earth. This is cool. Moreover, you can analyze your pace, elevation, or heart-rate performance.
I hope I’ll be ready for April. The only problem is that I’ll not be able to claim that I was badly trained when I’ll have to explain a counter-performance.

Back from Wengen

2006-02-06T11:36:00.000-08:00

I am just back from a fantastic week of ski in Wengen.

As you can see on the picture my ski instructor was very pretty and this also helps enjoying.
The weather was fantastically sunny and even if the snow was a bit too hard this is so enjoyable to ski with a blue sky.
Note that Wengen hosts the Lauberhorn Downhill Ski Race - surely the pistes are very impressive.

Dave is leaving Arjuna

2006-02-06T11:12:00.000-08:00

Ok, I don’t want to repeat what Mark said but my mate Dave is leaving Arjuna to take up a job with Microsoft.
All the best Dave!

Infravio Signs Strategic Partnership with IPT

2006-01-18T12:16:00.000-08:00

IPT (BTW, you will notice that IPT has a fancy new website) has recently signed an agreement with Infavio to distribute the company's flagship Infravio X-Registry Platform(TM) and provide sales and front-line support for Infravio in Europe.

I hope we will land deals on the top of this excellent product.

EJB container or not EJB container

2006-01-12T11:36:00.000-08:00

The following is how I recently compared EJB container and POJOs.
I really want to find out if people disagree or agree with those arguments. The idea is to find out how to justify the use of an EJB container.

Enterprise JavaBeans, EJBs. J2EE EJB containers provide component clustering, load-balancing, and application state replication for Web and EJB applications. They provide optimized high availability and process monitoring infrastructures that can be deployed in mission critical environments with no single point of failure.
EJB containers not only provide integrated security, transaction and management support but they are usually highly optimized, hence providing extremely fast response times and high throughput rates. Moreover, concurrency and locking models for EJBs enable high level of concurrent access without sacrificing data consistency.
EJB containers also provide support for event or message oriented programming. EJB containers provide transaction-aware concurrent components that are driven by java messages. This provides more robust and reliable message driven components compared to traditional message clients.

An alternative to using EJB container is to build applications using Plain Old Java Objects, POJOs. This requires a sophisticated framework like Spring, which conceals much complexity from the developer.
If the Spring framework simplify development by providing transaction support, inversion of control etc. it requires additional components to be used to achieve standard enterprise-grade features like clustering, high availability, event driven programming. Such components are usually available as open source solutions. For example, a clustering solution could be based on JBoss Cache. However, this not only complicates the deployment but introduce vendor locking dependencies.

JBoss acquires Arjuna

2005-12-06T00:53:00.000-08:00

This is now official! JBoss has acquired Arjuna’s products and my friends and ex-colleagues Mark and Kev are now happy JBoss employees.

Good luck to you guys and I am sure you will do a good job in helping JBoss developing its ESB product line.

Good luck to the ones that stay with Arjuna. I am sure that you will find THE great product idea.

SOA Challenged

2005-11-29T02:32:00.001-08:00

According to Alice LaPlante: SOA implementations are taking longer than expected, raising more challenges than anticipated, and returning ROI later than desired!!

Are we reaching the “Trough of Disillusionment” phase of the Hype Cycle or are we already reaching the “Slope of Enlightenment”?

BPEL

2005-11-25T08:22:00.000-08:00

I really think that people are speaking about BPEL without knowing what it is exactly. So here is a good definition that comes from a Cape Clear doc.
Business Process Execution Language for Web Services (BPEL4WS, or BPEL) is an XML Schema-based standard for defining process flows. It enables the composition of multiple synchronous and asynchronous Web services into an end-to-end business flow.
A BPEL script is an XML document that conforms to the BPEL schema. The BPEL script is interpreted at runtime by a BPEL processor that identifies keywords or activities and executes them as defined in the BPEL script.
BPEL is a programming language. Its programming statements enable developers to build robust processes that can:

Communicate by exchanging messages with other Web services using receive, reply, and invoke activities.
Control execution flow using while, switch, sequence, pick, flow
Handle faults that can occur during processing using catch and catchall fault handlers.
Model event-driven programming using onMessage and onAlarm event handlers.
Roll back transactions using compensation handlers.

Malta

2005-11-15T05:11:00.000-08:00

I am back form Matla where we had our corporate yearly seminar. We had two days of intensive work and one free day.

On the work level it was good to spend time with people. This helps discovering with whom you are working. The presentations were excellent. At least I now know who is doing what. Most importantly I have got a good idea of how the knowledge is spread within the company.

Speaking about Malta, I have not been impressed. I read somewhere in a tourist guide that Malta is the place to fall in love with the Mediterranean sun. Hum, it was rainy and I don’t like the sun that much! The food was not that good, it is very polluted (280 000 cars and an airport on a small island), they are plenty of ugly buildings and they don’t even have a proper golf! So, Malta is not the place I would go for my next holidays.

But if you love the Mediterranean sun it is a good place for you! Moreover, it is designed for English people, they drive on the right side of the road, they use UK plugs and they have excellent Indian food.

I should say also that I have discovered carting racing! It was very cool. Even if I finished last because I broke my transmission.

WS Extension

2005-11-01T12:34:00.000-08:00

There are two ways in which a service can be extended in a backward compatible manner:

Adding new operations
Updating existing operations: Changing service input or Changing service output

If adding new operations is obviously a backward compatible extension, updating existing operations is more challenging.

For extensibility purpose, Web Service parts should be defined as XML complex type elements. This pattern of document/literal is named document/literal wrapped. When using document/literal a WS can be extended as follow:

Extending Input
The XML complex type that defines the Web Service input can be updated by creating a new data type that is a subset of a base data type by either:

Adding new optional elements
Increasing the range of value of some base type elements
Redefining base type elements to have more occurrences

Those rules do not rely on specific schema design patterns. Note that document/literal wrapped style must be used.

Extending Output
To insure backward compatibility, extension made to a Web Service output XML complex type must be done as follow:

Add new elements to extend complex data types. This requires the base complex type to contain the extension element “”.

Create a new data type that is a subset of a base data type by either:

Redefining base type elements to have a restricted range of value
Removing optional base type elements
Redefining base type elements to have more restricted number of occurrences

Fribourg

2005-09-04T11:32:00.000-07:00

Today I took some pictures in Fribourg city center. As you can see Fribourg is a very nice medieval city. There are lot of very good restaurants, very nice little outdoors markets and even a red light district.

I am not trying to advertise Fribourg but it is definitely a very pleasant city. As you can see below, today it was even more medieval than usual:

Great North Run

2005-08-31T13:53:00.000-07:00

I haven’t blogged for long now. This is because I have been very busy at work. I will soon post several technical notes.
I should mentioned that I will be back in Newcastle from the 16th to the 19th of September. I will run my fourth Great North Run and this year I hope to run it in less that 1h 40 minutes.
I am seeing the GNR as part of my training for next April Paris’ Marathon. So I have decided to properly train and I have bought some magazines and books. I think that I will be bloging about my training very soon. The most difficult part of it will be giving up drinking beer and whisky :( According to my (French obviously) training book I am still allowed drinking a glass of red wine per day :)

Villars-sur-Glâne

2005-08-12T13:35:00.000-07:00

Jim has recently blogged about WDSOA’05. I’ll try my best to submit a paper about versioning. I really think that versioning is of great importance when designing WS. Whatever happens I’ll tell you soon more about my current thinking (via the paper or in this blog).

I have been told by some friends that this blog is too technical and therefore annoying to death. So, let’s go for some news. I have now moved to Villars-sur-glâne next to Fribourg. My flat is very cool, 110 m2 (I know that people from the UK will not have any fucking idea of what 110 m2 is but I could tell you that this is larger that my Newcastle’s house) with a 15 m2 balcony and a lovely view on the pre-Alps. I don’t want to publish photos of it because I am afraid to see too many people visiting me this winter. I was going to forget mentioning that most importantly my cellar is in a nuclear shelter. Yes, I may survive the next global nuclear ware, at least for few weeks as I haven’t any food in my cellar.

So, as I am living close to the Alps and because all my colleagues are mountain bike addicted then I need now to buy myself a mountain bike. Not a nice one like Thomas’ one but I’ll try to find a good one.

Validate or not validate: that is the question

2005-08-03T05:26:00.000-07:00

Should we validate incoming and/or outgoing SOAP messages against a schema? Shouldn’t we be able to switch validation on and off on our Web Service platform level? I am just concern that, for example when using a JAX-PC platform the Web Service platform does successfully transform invalid SOAP messages in JAVA objects.
I wonder if AXIS does it, ideally that should be done by the Castor stack. I am pretty certain that .net has this type of feature. It would be good if somebody can confirm that.
Regarding WebSphere they claim that:

“If a WebSphere web services client is developed with the supported programming model, like JAX-RPC and SAAJ, the web services engine will not serialize the request across to be a malformed XML document--i.e., the SOAP message should be structured according to the WSDL's style and use, and that it should conform with the WSDL's schema. A WebSphere web service won't accept a malformed, non-schema-compliant request that is not compatible with the WSDL describing the service, and if that request is malformed, the web services engine should throw some kind of exception.”

I am doubtful as simply because on of my document/literal wrapped Web Service response SOAP body contains the following:
....

losssets type="soapenc:Array" arraytype="p416:comindLossSetBase[2]"

....
Knowing that the schema describing the SOAP body is as followed (this is only a relevant snippet);
....

element type="comind:CILossSetSet" name="lossSets"
complextype
complextype name="CILossSetSet"
sequence
element type="" name="lossSet"

....
The SOAP body doesn’t validate against the schema! I guess that I have found an issue with WebSphere. Unfortunately, I haven’t managed to replicate this problem with some mock WSDLs. So, as I cannot give away our corporate data to IBM I only hope that IBM will give us an answer without the sacrosanct “standalone reproducible test case”.

So, should we validate or not? I would say that we should always validate attachment and certainly validate the SOPA body when our Web Service is externally exposed.

PS: Sorry about my SOAP code but I didn’t find a way of displaying the chevrons.

Java Web Service clients

2005-08-02T04:31:00.000-07:00

Service lookup

There are two families of Web Service clients which differ in the way code is written and services are invoked:

Unmanaged clients i.e. J2SE or J2ME clients ==> Service lookup is through the JAX-RPC ServiceFactory, a factory for the creation of instances of services access points. {JSR 101: "The JAX-RPC ServiceFactory is the standard way to look up Web services in a J2SE environment."}

J2EE container-managed clients ==> Service lookup is through JNDI lookup {JSR 109: "JNDI lookup is the standard way to look up Web services in a J2EE environment."}

JAX-RPC ServiceFactory

The JAX-RPC ServiceFactory is an abstract class which acts as a factory for instantiating JAX-RPC Services. It is vendor independent that helps writing portable code. The ServiceFactory is instantiated and used as follows:
javax.xml.rpc.Service service = ServiceFactory.newInstance().createService(...);

JNDI service lookup

J2EE container-managed clients are packaged into Enterprise Archives (.EAR) files and run from inside a J2EE container. In addition to the Java code, descriptors are also packaged into the archive. JAX-RPC defines the programming model for unmanaged clients, whereas JSR 109, "Implementing Enterprise Web services", defines the programming model for J2EE container-managed clients. One of the goals of JSR 109 is that its client programming model is compatible with JAX-RPC. However, JSR 109 does not recommend the use of the JAX-RPC ServiceFactory. It recommends clients use Java Naming and Directory Interface (JNDI) instead to obtain a Service Interface. This is a two steps process:

1) Instantiate a local JNDI Context ==> Context ic = new InitialContext();
2) Do a JNDI lookup for the Web service name in this context ==> Service service = (Service) ctx.lookup("java:comp/env/service/MyService");

The logical name of the Web service, in this case java:comp/env/service/MyService, is specified in the client application's deployment descriptor. JSR 109 recommends that all service reference logical names be organized under the service sub-context. With the client environment context being java:comp/env.

The JNDI lookup returns a JAX-RPC Service Interface. The J2EE container makes sure an implementation of the generic JAX-RPC Service is bound at the location specified in the deployment descriptor.

Service access

The J2EE container typically generates the service Interface Implementation, JAX-RPC Service, during deployment. The Service Interface Implementation acts as a factory for Service Endpoint Interface (SEI). A SEI is basically the Java representation of the Web service operations described in the WSDL port type element. The Service Interface Implementation must provide a static stub and/or dynamic proxy for all ports declared by the service element in the WSDL description. A container provider must support at least one of static stubs or dynamic proxies, but may provide support for both. When both are supported then the choice of generated stub or dynamic proxy is a deploy time binding information. IBM WebSphere 6 only provides support for static stubs. I think that it make a lot of sense as it is facter than dynamic proxies.

J2EE container-managed clients access and invoke Web Services as follow:

1. Get a JAX-RPC Service ==> Context ic = new InitialContext();
Service service = (Service) ctx.lookup("java:comp/env/service/MyService");
2. Obtain a SEI using the JAX-RPC Service's getPort() method ==> MyPort aPort = (MyPort) service.getPort(MyPort.class);
3. Invoke the Web Service operations ==> aPort.myOperation(myArg);

Unmanaged clients i.e. J2SE or J2ME clients use one of the three following methods for accessing and invoking Web Services:
• Stub
• Dynamic Proxy
• Dynamic Invocation Interface (DII).
See the following documents for more details about those three techniques:
· http://java.sun.com/webservices/docs/1.3/tutorial/doc/JAXRPC5.html
· http://www-128.ibm.com/developerworks/webservices/library/ws-javaclient/

Welcome Thomas

2005-08-02T04:26:00.000-07:00

I like to welcome my friend Thomas.
You should definitely have a look at his excellent blog, there is even a picture of me half-naked ;(

RAD6 a hate/love relationship

2005-07-13T07:14:00.000-07:00

I will qualify my experience with RAD6 as hate/love relationship. It has a lot of cool features but is still pretty unstable. I am currently reinstalling it has blew up when I tried to secure one of my servers! So, this not to say that I currently hate it very much this is just that I am very angry.

One thing that could be useful for unfortunate RAD6 users it to know that in RAD6, your server configs are stored in the runtime profile directories and they are not local to your workspace. If you want a different server config for each workspace, you need to use the ProfileCreation tool (rad6/runtimes/base_v6/pctWindows.exe) to create a new profile for WAS and then point your server definition in RAD6 to the new profile.) Furthermore, you can have a look at this technote that describes the problem in detail and explain how to correct this using the AdminConsole.

I am back to my freshly installed RAD6 for more fun.

Web Services Proof of Concept

2005-07-04T03:49:00.000-07:00

I am currently working on a Web Services Proof of Concept for a Zurich based Reinsurance company. This figure illustrates the technologies that I will be evaluating (I hope that my figure has been added):

Performance is obviously an issue and I hope I will be able to contribute to the “SOAP slow or fast debate?” debate. Moreover, I’ll report very soon about my experience with RAD 6.

programming (AOP) have in common.

2005-06-20T04:28:00.000-07:00

I went through a very interesting paper about AOP and Java Dynamic Proxies. I’ll have to look at JBoss AOP to find out how it is implemented.

SOAP encoding

2005-06-17T06:54:00.000-07:00

I have eventually found a good explaination on why this is a very bad idea to use SOAP encoding. SOAP encoding only exists for historical reasons. The SOAP authors didn’t initially have access to XSD so they wrote the SOAP encoding rules, which explain how to serialize an instance of the SOAP data model to a SOAP message. It was left to SOAP implementers to map their own technologies to the SOAP data model. When you create a WSDL binding, you have to specify whether the SOAP messages contain literal or encoded instances of the schema constructs the operations use. If you choose "literal," you are saying that the XML Schema constructs your WSDL definitions refer to are concrete specifications of what will appear in your SOAP message bodies. If you choose "encoded," you are saying that the XML Schema constructs your WSDL definitions refer to are abstract specifications of what will appear in your SOAP message bodies; these can be made concrete by applying the rules defined by SOAP encoding.
And then we can conclude as Tom noticed: "if you use SOAP encoding, then you can't validate the message with an XML Schema, and you can't transform the message using XSLT" this is obviously a bad idea!

Document vs. RPC style--why is it a big deal?

2005-06-08T06:49:00.000-07:00

Document vs. RPC style--why is it a big deal?

Scotland

2005-06-01T03:28:00.000-07:00

I am just back from a fantastic trip in Scotland. I went there with a friend of mine with the intension to play golf and visit distilleries and so we did!
As we didn’t want to drive miles and miles around we stayed in the low land on the west coast.
Our fist stop was to visit the Auchentoshan distillery that lies immediately before Glasgow’s Erskine Bridge on the A82. We had the ultimate pampering experience as we were offered four different whiskies 10, 12, 21 years old and the famous three woods. I should say that I like very much those whiskies! Then we had to drive (oups we shouldn’t have done that) to Largs. We stayed overnight in the Carlton Guest House. Largs is a very nice little town with very good pubs.
The next day we took the ferry for the island of Cumbrae where we played golf in the millport golf club. This was the ultimate golf experience as this golf is beautiful even when it is pouring and extremely windy! We then stayed in KILMARNOCK for the night. We slept in picturesque 18th century farmhouse LAIGH LANGMUIR with a fantastic old lady that thinks that German and French speak the same language :)
The next day we drove to the island of Arran where we settle down in Whiting Bay in the Mingulay Bed and Breakfast. This was the best B&B, maybe because it was the most expensive one. We visited the Arran distillery and then tee-off in the lochranza golf course. Maybe we should we have gone for the other way round but I should say that I played quite well that day :)
The morning of our last day, that was fantastically sunny, we played on the shiskine golf course. This is a unique 12-hole course has achieved the distinction of being included in the top 100 best courses in Britain for the past two years! This was absolutely great!
We then took the fery back on the main island and drove back to Newcastle. It was a great experience all along and an excellent end of my five years long British experience.

Posting Licence

2005-05-25T04:12:00.000-07:00

I have been posting in technical Forums for a long while now. I really think that people should take a tutorial before being allowed to post. I am even thinking of proposing a “Posting Licence” that would be a compulsory part of any IT degree.
Apart from the usual recommendations: “be polite”, “say hello” etc., the “Posting Licence” training should emphasize the following:

Before posting you should use Google or any other search engine to try solving your problem. For example, I answered today the following question:
“If anybody knows about the difference between Message DrivenBean and JMS please clarify to me.”
The answer is: USE GOOGLE with the key words “MDS tutorial” and “JMS tutorial” and please take time to go through those tutorials! People can’t just assume that somebody is going to post a master course.
Be sure that your question is related to the forum’s technology. This type of post if for example very irritating when found in the JMS Sun Forum:
“i want to send message to mobile through my computer, is it possible?”
This is not a JMS related question and again please USE GOOGLE before posting! The key words “SMS java” will lead you on excellent sites with all the required information.
People usually answer questions at part of their spare time so, please send back an acknowledgement. Moreover when you are using the Sun forum please allocate the promise Duke Dollars! I would like to eventually get my free Mug!
Do not advertise your own product! This is one is for me as I have been evangelising Arjuna’s products in the Sun JMS Forum. I have even managed to upset Andreas Mueller . But the war is now over :)
Try not asking product specific questions as it shows the world that etheir:
a) You didn’t buy a licence
b) You bought a very expensive licence but cannot afford the support premium.

If only everybody could get a posting licence, life would be easier!

2005-05-20T02:42:00.000-07:00

Arnaud

The butterfly effect

2005-05-19T06:15:00.000-07:00

The "Butterfly Effect", or more technically the "sensitive dependence on initial conditions", is the essence of chaos. I recently had an excellent illustration of it. We all know that my compatriots are master in making chaotic strikes! And yet again they strike!
The French air traffic controllers were on strike this Monday. Don’t ask me why because I buddy don’t know! But they managed to delay my flights! My flight from Valencia to London was delayed by 2 hours because of them. So is this because of the butterfly effect? Not really because we had to fly over France and those %$%$ controllers were throttling the traffic. Ok, but what about delaying a London-Newcastle flight by 3 hours! Isn’t it a good illustration of the butterfly effect? The French air traffic controllers did manage to delay a London-Newcastle flight by 3 hours!!! I still don’t believe it but at least this is what I have been told!

Enterprise Integration Patterns

2005-05-09T04:03:00.000-07:00

A couple of weeks ago I read this excellent book: Enterprise Integration Patterns : Designing, Building, and Deploying Messaging Solutions. Gregor Hohpe, Bobby Woolf provide us with 65 patterns (in the manner of the classic Design Patterns). Each pattern shows one typical problem in integrating applications, and how it is solved. Each pattern gives enough implementation details so it is clear how it would work, and an example or two so it is clear how it works in practice.
Even if nothing was new for me I just love very much the clarity of the book and the pattern icons that are very pretty and useful to communicate! I am wondering if somebody as done some UML libraries with them?
Definitely a must have for system integrators that want to embrace the bright side of asynchronous communication.
I am now reading Patterns of Enterprise Application Architecture from Martin Fowler. Those guys from ThoughtWorks are definitely working hard!

IPT

2005-05-04T03:26:00.000-07:00

I haven’t posted in my Blog for now a long time. But here I am back and I will for now on be posting at least an entry a week.
Things have been moving:
- I have resigned from Arjuna Ltd
- I’ll start my new job in Switzerland the 6th of June. I am joining a consultancy company IPT (http://www.ipt.ch/content/main/framesource.asp). This company is very dynamic. I am pretty confident that I’ll learn a lot as I should mainly be working on integration projects (IPT has a great deal of experience with Sonic’s ESB).
- I am very busy moving my family across
- I am much exited to start learning German very soon. To be honest, my aim is to quickly speak a better German than my best friend Thomas (he is German) speaks French.

I’ll like to wish the very best of luck to all the Arjuna boys (I still have shares so, go on guys!!). I have learned a lot with this company but I just think that now it time for me to move on.

MDB

2005-01-25T06:36:00.000-08:00

I found in the JMS forums that people usually don’t know the difference between MDB management modes. The following summary should clarify things:

With container-managed transactions, the MDB container sets the boundaries of the transactions. Typically, the container begins a transaction and receives a message within it (On the implementation level it is a little bit more complicated than that and I might Blog more details if I am asked). It is the responsibility of the container to enlist other Bean operations (invoked within the onMessage code) whit the running transaction. The container then commits the transaction just after the onMessage method exits or rolls it back when setRollbackOnly is set or when an exception is thrown.

With bean-managed transactions, the code in the MDB explicitly marks the boundaries of the transaction. It is the responsibility of the programmer to get a transaction, to enlist resources and to decide of its outcome. It is not possible to associate the received message with a transaction as messages are delivered to the MDB within a standard session (not an XA Session as it is the case for CMT).

Note that this is also true for the Arjuna MDS (Message Driven Service) container. I’ll tell you more about MDS later.

Messaging in J2EE 1.4

2005-01-24T13:21:00.000-08:00

Today I had a look through developerworks at IBM's, and stumbled across an article called 'Get the message: Messaging in J2EE 1.4 from ibm.com .

The paper says that the J2EE 1.4 introduces changes to the way an application server uses JMS. In particular, you can only have one active (not-closed) Session per connection at any one time. This could be a bit confusing at first but that's part of the EJB spec. A call to createSession returns always the same session. In J2EE 1.4 this has moved from the app server to a JCA 1.5 resource provider. So for outbound messaging it has only 1 session per connection, so in fact the connection will be the entity for transactional control like it is the case for a database connection.

My first post

2005-01-17T13:04:00.000-08:00

I have been reading Mark Little’s weblog (http://markclittle.blogspot.com) for few months now and I have been inspired (I really recommend it, Mark is an excellent writer) and decided to create my own one. I take that as an exercise of style that should help me improving my written English (I need feedback for that).
I don’t know exactly what I am going to talk about but I would guess on general IT, Javaish stuff as well as philosophical comments on everything. I should talk about my leisure activities: biking, running (It’s time to register for the great North Run!!!! Hurry up!), swimming, golf, music cinema etc… I could as well be inspired by management studies and this semester I may bore you with some accounting things.
We will see what will inspire me the most. I may even start writing a fiction, who knows.