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J2EE, Agility and SOA

September 21st, 2009
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Review of the papers

Review of the papers Xebia
The review of the papers of actualit ava / J2EE weekly propos par Xebia.

Actuality editors / SSII

Agility

SOA

The corner of technology

Ev nements of our community in France and abroad

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January 2nd, 2009
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What you perhaps missed in the fourth quarter 2008

Here is the list of tickets most read on this blog in October, November and December:

RIA CONTEST: FLEX / Silverlight / GWT / Echo3 / JAVAFX

After the Xebia Web Framework Contest of last year, the topic of XKE of October was a contest new devoted in .

The purpose of this day was to develop an application of management of playlist of music pieces. In promoters of Agile methods, specifications were given in form of Product Backlog. Three sprints of a length of 90 minutes allowed all to follow the evolution of different achievements. A web SOAP service gave different data: Artist, Album, Titles and Cases of album.

Five teams were constituted, five frameworks were therefore chosen:

  • FLEX 3
  • Beta 2 Silverlight 2.0
  • GOOGLE GWT 1.5
  • Echo3
  • JAVAFX PREVIEW SDK

At the end of this day, every team could express a significant return of experience.

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Diagnosis of remote JVM

To develop a Popular dance application, it is well. To make her competitive, it is better.

However, who says "performance" , says "measure" . Indeed, it is necessary to be able:

  • know the parametres of launching of JVM,
  • measure footprint memory and the behaviour of Garbage Collector,

This article is going to describe in a first part the different tools allowing to collect this information in place. The second part concentrates on means to get this same remote information.

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Analyse memory of JVM

Tuesday, 10 am
- Production  Hello, plan, since 10 minutes they see crossing ' OutOfMemoryError ' messages. What does be made?  
- Plan  Augment the memory of JVM, double it value of option-Xmx  

Tuesday, 1 pm
- Production  Hello, plan, since 5 minutes they again see crossing ' OutOfMemoryError ' messages. What does be made?  
- Plan  Augment the memory of JVM, still double the value of option-Xmx  

Tuesday 18 hours
- Production  Hello, plan, since 2 minutes they see crossing still ' OutOfMemoryError ' messages. What does be made?  
- Plan  Hushed up, up, up.. 
- Production  More team plan, the night is going to be long  

This small stage is a classic, an air of d j vu but what to make? If your application has already suffered a battery of technical tests, to augment memory is seldom good solution. The stage described above lets think of be traditionally called an Escape Memo (Memory Leak). In reality, with recent JVM, escape memo does not exist, I prefer speaking about accumulation of unwanted objects. This article is going to show you how brings to light this accumulation with tools jmap, jhat and .

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November 27th, 2008
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Analyse memory of JVM

Tuesday, 10 am
- Production  Hello, plan, since 10 minutes they see crossing ' OutOfMemoryError ' messages. What does be made?  
- Plan  Augment the memory of JVM, double it value of option-Xmx  

Tuesday, 1 pm
- Production  Hello, plan, since 5 minutes they again see crossing ' OutOfMemoryError ' messages. What does be made?  
- Plan  Augment the memory of JVM, still double the value of option-Xmx  

Tuesday 18 hours
- Production  Hello, plan, since 2 minutes they see crossing still ' OutOfMemoryError ' messages. What does be made?  
- Plan  Hushed up, up, up.. 
- Production  More team plan, the night is going to be long  

This small stage is a classic, an air of d j vu but what to make? If your application has already suffered a battery of technical tests, to augment memory is seldom good solution. The stage described above lets think of be traditionally called an Escape Memo (Memory Leak). In reality, with recent JVM, escape memo does not exist, I prefer speaking about accumulation of unwanted objects. This article is going to show you how brings to light this accumulation with tools jmap, jhat and

jmap

jmap is the tool which allows to perform photographs of the memory of JVM. Two options are particularly interesting: the bar chart and the dump.

October 27th, 2008
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Review of the papers Xebia

Review of the papers Xebia
The review of the papers of actuality Popular dance / weekly J2EE offered by Xebia.

Actuality editors / SSII

The corner of technology

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October 22nd, 2008
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Diagnosis of remote JVM

To develop a Popular dance application, it is well. To make her competitive, it is better.

However, who says "performance" , says "measure" . Indeed, it is necessary to be able:

  • know the parametres of launching of JVM,
  • measure footprint memory and the behaviour of Garbage Collector,

This article is going to describe in a first part the different tools allowing to collect this information in place. The second part concentrates on means to get this same remote information.

Read the continuation of this article

September 22nd, 2008
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Review of the papers Xebia

Review of the papers Xebia
The review of the papers of actuality Popular dance / weekly J2EE offered by Xebia.

Agility

The corner of technology

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September 15th, 2008
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Review of the papers Xebia

Review of the papers Xebia
The review of the papers of actuality Popular dance / weekly J2EE offered by Xebia.

The corner of technology

Ev nements of our community in France and abroad

Read the continuation of this article

July 21st, 2008
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Review of the papers Xebia

Review of the papers Xebia
The review of the papers of actuality Popular dance / weekly J2EE offered by Xebia.

Actuality editors / SSII

RIA

The corner of technology

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March 12th, 2008
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Traditional generation GC (JDK6) VS GC GARBAGE FIRST (JDK7)

The empirical analysis shows that in an application the vast majority created objects are almost immediately destroyed. It is true all the more for applications web and/or stateless where most objects are created to treat a request and can therefore be destroyed just after this treatment. From this official report results the idea of not treating similarly the newly created objects and those who exist since longer. Garbage Collector which uses realisation based on this principle is called generation GC. It is possible to fix two categories of objectives when GC is optimised: reduce pauses or augment the debit. These objectives are in general orthogonal (the reduction of the length of pauses is made to the detriment of the debit, and vice versa), they often depend on the type of applications: in an interactive application, we will favour pauses, and on the contrary, in batch one, alone the debit counts.

The continuation of the ticket is broken down into two parts:

  • The first one describes the functioning of traditional generation algorithms (current Realisation of JVM SUN)
  • The second itemises the new algorithm which SUN tries to grow for his INTENDED JVM

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