How to handle Memory Leaks in Java/J2EE Applications ?

In this article, I have tried to analyze the various causes which may lead to Memory Exception.

Once an ‘OutOfMemoryException’ is thrown, how best can it be handled has been discussed in this artilce.

OutOfMemoryException is thrown when there is not sufficient available memory to carry out a requested activity. In this article, I have tried to illustrate the different methods by which memory leaks can be handled in Web Applications.

 

More Info : http://vinaytechs.blogspot.com/2009/11/how-to-handle-memory-leaks-in-javaj2ee.html

Performance Benchmarks a Webserver

ApacheBench is a command line computer program for measuring the performance of HTTP web servers, in particular the Apache HTTP Server. It was designed to give an idea of the performance that a given Apache installation can provide. In particular, it shows how many requests per second the server is capable of serving.

The ab tool comes bundled with the standard Apache source distribution, and like the Apache web server itself, is free, open source software and distributed under the terms of the Apache License.

More Info : Performance Benchmarks a Webserver

Inside Apple iPhone

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iPhone Processor

• Application Processor (Differs in iPhone, iPhone 3G and 3GS)
• Baseband Processor (Modem – Again differs with versions)
• Both of these processor belongs to ARM category

 

 

 

More Info : Inside Apple iPhone

Dynamically Repeating Control/Container in Adobe Flex

Introduction

• Used for repeating simple UI components
• Repetition can be controlled by an array
• Repeater components look like containers in the code but they are not containers
• Repeaters don’t have automatic layout functionality of containers.
• Purpose of using: To form a series of subcomponents as per the contents of a specified data provider.
• For dealing with large amount of data; use controls like HorizontalList, TileList, and List

More Info : Dynamically Repeating Control/Container in Adobe Flex

Tips & Tricks for SQUID (Proxy) Server

This article will be helpful to improve your squid performance in any hectic and slow bandwidth / traffic kind of scenario. This will also helpful to the organization, who will use the only one Squid Server Hardware and giving the internet access to more then 1000 users. Even, you can bypass or stream line your SSL / SAFE ports for any outgoing traffic, which needs to be allow.

More Info : Tips & Tricks for SQUID (Proxy) Server

Overview Of CICS [Customer Information Control System]

CICS (Customer Information Control System) is a transaction server that runs primarily on IBM mainframe systems under z/OS and z/VSE.

CICS is a transaction manager designed for rapid, high-volume online processing. This processing is mostly interactive (screen-oriented), but background transactions are possible.

While CICS has its highest profile among financial institutions such as banks and insurance companies, over 90 percent of Fortune 500 companies are reported to rely on CICS (running on z/OS) for their core business functions[citation needed], along with many government entities. CICS is used in bank-teller applications, ATM systems, industrial production control systems, insurance applications, and many other types of interactive applications.

More Info : Overview Of CICS [Customer Information Control System]

Asynchronous mailing through Tomcat6 and Seam 2.1.2

This article assumes Seam application is already configured on Tomcat.

Steps to implement Asynchronous mailing

• Copy following mail related jars from jboss-seam-2.1.2\lib to the projects’ \WEB-INF\lib folder.
  1. Jboss-seam-mail.jar
  2. Mail.jar
  3. Activation.jar
• Copy quartz.jar file from jboss-seam-2.1.2\lib to the projects’ \WEB-INF\lib folder.

More Info : Asynchronous mailing through Tomcat6 and Seam 2.1.2

Do you know Credit Card Validation Algorithm ?

A Web Application commonly involves transactions which require processing of Credit Card information.

Implementation of basic credit card validation ensures that the final overhead involving the actual verification of credit card numbers is reduced to a great extent. In this white paper we have elaborated one such credit card validation algorithm, LUHN Algorithm, and presented a JAVA code to implement it.

More Info: Do you know Credit Card Validation Algorithm ?

Final and Abstract Classes – Back to Basics :-)

Final Members: A way for Preventing Overriding of Members in Subclasses

All methods and variables can be overridden by default in subclasses.

This can be prevented by declaring them as final using the keyword “final” as a modifier. For example:

final int marks = 100;

final void display();

This ensures that functionality defined in this method cannot be altered any. Similarly, the value of a final variable cannot be altered.

More Info : http://vinaytechs.blogspot.com/2009/11/final-and-abstract-classes-back-to.html

Top 10 Blackberry Troubleshooting Tips

Use this article to resolve a problem involving or relating to the BlackBerry wireless device, before engaging the help of your BlackBerry technical support provider.

More Info : Top 10 Blackberry Troubleshooting Tips

DB2 Tuning Tips

1) Take out any / all-Scalar functions coded on columns in predicates. For example, this is the most common:

SELECT EMPNO, LASTNAME

FROM EMPLOYEE

WHERE YEAR(HIREDATE) = 2005

Should be coded as:

SELECT EMPNO, LASTNAME

FROM EMPLOYEE

WHERE HIREDATE BETWEEN ‘2005-01-01’ and ‘2005-12-31’

SSH configuration in Solaris 8

Solaris 8 doesn’t come with the SSH and SFTP like features, to enable these we have to configure and install a third party package OpenSSH.

/dev/random and /dev/random built-in, but patches have been released to correct  this. The packages need to be on the system to use ssh properly are openssl,  openssh, zlib and libgcc .All the packages are freely available on www.sunfreeware.com.

More Info : http://vinaytechs.blogspot.com/2009/11/ssh-configuration-in-solaris-8.html

 

CSS Best Practices and Cross-browser Compatibility

This article is consolidation of the best practices which are followed or taken care during the development when a web page is styled using a external or inline style sheet referred to as CSS (Cascading Style Sheet). The best practices are arrived at after evaluating and analyzing the working web pages. Some of the concepts shared in this article are widely available on the internet but few are exclusively on the basis of experience and learning. Cascading style sheets are, in general terms, a collection of formatting rules that control the appearance, or presentation, of content on a web page. Implementing CSS within a page or site is done in one of three ways

More Info : http://vinaytechs.blogspot.com/2009/11/css-best-practices-and-cross-browser.html

Clustering in JBoss Application Server

Whenever business wants to run their IT applications in a scalable and reliable way, they need to have a highly sophisticated environment, which suits their needs. The motto is to keep the business up and running, all the time 24 x7, without any breaks and troubles. Performance also cannot be compromised in this fast growing world. For any J2EE application built and deployed in most widely used, open source application Server like JBoss, Clustering comes in handy to take care of the scalability, reliability and the application availability with no compromise on performance as well. This paper will describe about the clustering concepts in JBoss Application Server.

More Info : http://vinaytechs.blogspot.com/2009/11/clustering-in-jboss-application-server.html

Excel Generation using Dynamic Jasper-3.0

Dynamic Jasper (DJ) is an open source free library that hides the complexity of Jasper Reports, it helps developers to save time when designing simple/medium complexity reports generating the layout of the report elements automatically.

DJ creates reports dynamically, defining at runtime the columns, column width groups, variables, fonts, charts, crosstabs, sub reports page size and everything else can be defined at design time.

More Info : http://vinaytechs.blogspot.com/2009/11/excel-generation-using-dynamic-jasper.html