There are two primary measures of garbage collection performance. Throughput is the percentage of total time not spent in garbage collection, considered over long periods of time. Throughput includes time spent in allocation (but tuning for speed of allocation is generally not needed.) Pauses are the times when an application appears unresponsive because garbage collection is occurring.
Users...
Saturday, December 25, 2010
GARBAGE COLLECTION IN JAVA - GENERATIONS
At initialization, a maximum address space is virtually reserved but not allocated to physical memory unless it is needed. The complete address space reserved for object memory can be divided into the young and tenured generations.
The young generation consists of eden plus...
Sunday, December 19, 2010
JSESSIONID & APACHE STICKY SESSION
Recently I and my team implemented the sticky session feature from apache to our application. After that we started getting frequent session time out issue from testing team. After a long analysis we found, the browser is not flushing the JSESSIONID each time the new session get created from the server. So if the cached session is of node 1 and new session is get created from node 2 the user used...
RESOURCE CACHING FROM APACHE
1. Uncomment the following lines from the "$apache_home/conf/httpd.conf".
LoadModule expires_module modules/mod_expires.so
LoadModule headers_module modules/mod_headers.so
LoadModule deflate_module modules/mod_deflate.so
2. Add the following lines to "$apache_home/conf/mod-jk.conf" at the last.
#cache settings
ExpiresActive On
Options FollowSymLinks MultiViews
...
STATIC RESOURCE APACHE PROXY
1. Dump your application static resources i.e images, css, html, javascript to "$apache_home\htdocs\".
2. Add the following lines to the "$apache_home/conf/mod-jk.conf" bellow "# Let Apache serve the images"
JkUnMount /__application__/css/* node1
JkUnMount /__application__/images/* node1
JkUnMount /__application__/xmlhttp/* node1
JkUnMount /__application__/js/* node1
Note: In case of multiple...
APACHE SETUP FOR JBOSS
1. Download Apache HTTP 2.2 from here(http://olex.openlogic.com/package_versions/download/9478?package_version_id=5577&path=openlogic%2Fapache%2F2.2.17%2Fopenlogic-apache-2.2.17-windows-ins-no-ssl-1.zip)
2. Unzip the file and double click on the installation file. Next follow the screen instructions to install.
3. After installation click the test configuration to test if Apache is...
Saturday, November 6, 2010
GPS with JGPS - Setup Testing
I am playing around the GPS module since quite some time and got a new JGPS java api to interact with. I have a serial out put GPS module. Check out my GPS setup. This particular API has got a very good interface for USB, Serial and bluetooth GPS devides.This has native API for both Unix and windows platform. In unix plat form this supports both linux and solaris. This API has got a very meaning...
Thursday, October 28, 2010
NMEA GPS Reads
GPS modules typically put out a series of standard strings of information, under something called the National Marine Electronics Association (NMEA) protocol. More information on NMEA standard data strings can be found at this site.
GPS receiver gives the reading starting with the following strings and each string appended data has its own significant.
$GPGGA: Global Positioning System Fix Data
$GPGSV:...
Sunday, October 24, 2010
GPS Receiver Module - iW-GPS-01
Got iW-GPS-01(with Active Antenna) and iWave's GPS Platforms. The GPS board is mounted on a GPS platform with serial out and has a external antenna. The board has got a serial port and a power input.The board operates on 5 - 35 V input.
Full specification attached here.
Reads I got from...
Tuesday, September 28, 2010
EASY JSF WITH ECLIPSE - BASICS
What is JSF
JavaServer Faces (JSF) is a UI component based Java Web application framework. JSF is serverbased, e.g. the JSF UI components and their state are represented on the server with a defined life-cycle of the UI components. JSF is part of the Java EE standard.
A JSF application run in a standard web container, for example Tomcat or Jetty .
A JSF application
A JSF...
Sunday, September 26, 2010
EASY JSF WITH ECLIPSE - CONFIGURATION
This tutorial was developed with Java 1.6, JavaServerFaces 1.2, the Apache MyFaces JSF implementation, Tomcat 6.0 and Eclipse 3.5.
Eclipse & Tomcat
For JSP development you need the Eclipse and an installed Tomcat.
JSF library
A JSF library is required. We will later...
Monday, August 30, 2010
INCOMPLETE ROAD MAP TO Thread.run()
When it comes to java thread, I always try to dig how the Thread.run() method get executed when, the Thread.start() method get called. Recently, I downloaded the JDK 5 source code and started looking into the implementation.
There is two way we can create user defined threads and in both the scenarios, we used to call the Thread constructor and that internally calls the Thread.init(). init()...