DraK's Klog

Amdahl's law, named after computer architect Gene Amdahl, is used to find the maximum expected improvement to an overall system when only part of the system is improved. It is often used in parallel computing to predict the theoretical maximum speedup using multiple processors.

The generalized Amdahl's law is:

For the last two and a half months, Vincent Partington has been blogging about the top ten Enterprise Java Application Performance Problems. The list:

• #10 - Excessive logging
• #9 - Incorrect application server configuration
• #8 - Incorrect usage of Java EE
• #7 - Unnecessary use of XML
• #6 - Improper caching
• #5 - Excessive memory usage
• #4 - Badly performing libraries
• #3 - Incorrectly implemented concurrency
• #2 - Unnecessary remoting
• #1 - Incorrect database usage

Very handy.

Testing JavaMail applications is more difficult than necessary, because it involves in a lot of set up outside the test program. Doing this correctly in a portable way so that anyone in your team can run the test is almost impossible.

Hyperic HQ 3.0.0 has been released. Hyperic HQ is an asset management package for data centers, showing users application, hardware, and resource data including system loads and availability.

Hyperic HQ allows you to track log events and configuration changes, plan alert escalations, and see trends in how the application stack performs.

jPOS is a Java® platform-based, mission-critical financial transaction library/framework that can be customized and extended in order to implement financial interchanges.

I gave up hope in managing to get a JMS console to work with JBoss when a colleague of mine told me that he had successfully managed to get Hermes JMS 1.12 to work with JBoss AS 4.0.5 GA.

Simply follow the instructions given in this flash presentation.

Finally ...

Have you ever wanted to try OSGi, but found setting up the build and working out the manifest too much of a chore?

If so then help is at hand - over the last few months, I have been developing a set of Maven archetypes and plugins to automate much of the manual work required in creating an OSGi project.

Nice article on eclipse 3.2 based refactoring.

Amazing ...

JFeature is an open source feature/requirement coverage tool that facilitates focusing on requirements as you develop code. It lets you leverage from standard development practices to get more insight into the requirements covered by the code.

Very convenient to build MSI installer files.

This is a Maven 2 plugin that allows you to run JMeter tests as part of the build.

Of course, it claims to be different:

• Guice empowers dependency injection.
• Guice cures tight coupling.
• Guice enables simpler and faster testing at all levels.
• Guice reduces boilerplate code.
• Guice is type safe.
• Guice externalizes configuration when appropriate.
• Guice lets you compose your application of components which are truly independent.
• Guice reports error messages as if they will be read by human beings.
• Guice is the anti-static.
• Guice is small and very fast.

TCS (Textual Concrete Syntax) is a DSL for the specification of textual concrete syntaxes.

This document presents an ATL implementation of a metamodel independent approach to the representation of model differences which is agnostic of the calculation method. Given two models being differenced which conform to a metamodel, their difference is conforming to another metamodel derived from the former by an automated transformation. Interestingly, difference models are firstclass artifacts which in turn induce other transformations, such that they can be applied to one of the differenced models to automatically obtain the other one.

I'm impressed every day with I find in the eclipse ecosystem ...

Whole is a platform for developing new languages, manipulating them using domain notations and transforming them to executable code

The Whole Platform includes a modeling framework, a generative system, a family of languages, and domain editors integrated with the Eclipse platform.
The languages boundled with the Platform include popular languages such as Java and XML together with some new domain languages used for modeling the structure, the behavior, the persistence and the notations of a language.

Enfin, une implémentation Open Source de repository MOF2 pour Java:

The Textual Editing Framework (TEF) allows you to write text based editors for your models. An editor written in TEF is based on a meta-model and therefore allows editing of instances for this meta-model. TEF editors provide an extensive set of modern text editor features without additional efforts. You get, for example, syntax highlighting, content assist (code completion), intelligent navigation, or visualisation of occurrences by simply describing your model notation as a set of template classes.

• UmlAsSketch
• UmlAsBlueprint
• UmlAsProgrammingLanguage

This library comes with a Textual UML syntax. Maybe the parser can be reused.

There is also a plugin for Eclipse.

This paper describes the TMF (Textual Modeling Framework) project, a GMF equivalent which instead of generating visual syntaxes would generate textual syntaxes.

This would be a major step forward in terms of ease of model edition.

Simply an astonishing idea !

Object-Process Methodology (OPM) is a holistic, integrated approach to the study and development of systems in general and information systems in particular.

In most interesting and challenging systems structure and behavior are highly intertwined and hard to separate. Meeting this modeling challenge, stateful objects and processes that transform them describe the function, structure and behavior aspects of the modeled system within a single framework in a domain-independent manner and without highlighting one aspect at the expense of suppressing another.

OPM is supported by OPCAT- Object-Process CASE Tool. Using OPCAT, OPM is studies in leading academic institutes and used in industry.