Network RAM

Network RAM enables nodes with over-committed memory to swap pages over the network, storing them in the idle RAM of other nodes and avoiding swapping to slow, local disk.

As several parallel or parallel and sequential applications are simultaneously running on the system ,there are likely to be imbalances in RAM usage across nodes. Network RAM systems take advantage of imbalances in RAM usage and allow nodes with over-committed RAM to locate and use the idle RAM of remote nodes as backing store; pages are “swapped out” over a fast network and stored in the idle RAM of other nodes. This disparity will likely continue to grow because disk speeds are limited by mechanical movement.

Large amounts of idle cluster memory are almost always available (even when some nodes are overloaded), and that large chunks are available for significant amounts of time. As a result, a Network RAM system should be able to find usable amounts of idle RAM to store swapped pages.

Nswap: A Network Swapping Module For Linux Clusters

Nswap is a Network RAM system for general purpose Linux clusters and networked systems. Cluster applications that process large amounts of data, such as parallel scientific or multimedia applications, are likely to cause disk swapping on individual cluster nodes.

Cluster applications that process large amounts of data, such as parallel scientific or multimedia applications, are likely to cause swapping on individual cluster nodes.

Nswap is implemented as a loadable kernel module that runs entirely in kernel space on an unmodified Linux 2.6 kernel. It transparently and efficiently provides network RAM to cluster applications. Nswap uses a peer-to-peer design (vs. a centralized system) that scales to large clusters. A novel feature of Nswap is its adaptability to changes in a node's memory load; when a node needs more memory for its local processes, it acts as an Nswap client swapping its pages over the network, and when a node has idle RAM space it acts as an Nswap server caching other nodes' swapped pages.

Ref: Reliable Adaptable Network RAM, Swarthmore College, USA.

How to apply Gradient Color to GUI Components in JAVA

• It’s always said that first impression is last impression. This quote is also applicable in the field of Software Development. To impress your client you must have a pretty good GUI (Graphical User Interface) especially when that client is not belongs from computer field.
• So, hereby I am going to share about color management for GUI components. A component with gradient color looks good rather than a solid color.
• I hope you know about Java Applet. In which we are implementing a ‘paint’ method which draws component on applet screen or on frame. We are going to use that same method here also.
• This method can be applied to any java GUI component such as JPanel, JButton, JTabbedPane, JToggleButton, JMenu, JMenuItem.

Let’s consider a component JPanel , as it’s a swing component it is preceded by ‘J’.

Generate a java class file and name it as MyJPanelGradient.java.

A code to paste in MyJPanelGradient.java file.

package pkg;

import java.awt.Color;

import java.awt.GradientPaint;

import java.awt.Graphics;

import java.awt.Graphics2D; // Imported Libraries

import javax.swing.JPanel;

import javax.swing.BorderFactory;

import javax.swing.border.LineBorder;

import javax.swing.border.TitledBorder;

public class MyJPanelGradient extends JPanel {

@Override

protected void paintComponent( Graphics g ) {

if ( !isOpaque( ) ) {

super.paintComponent( g );

return;

}

Graphics2D g2d = (Graphics2D) g;

//to get height and width of the component

int w = getWidth();

int h = getHeight();

//generating two colors for gradient pattern

/*parameters are consentration of Red, Blue and Green color in HEX format*/

Color color1 = new Color(0xeb,0xeb,0xeb);

Color color2 = new Color(0xa2,0xbd,0xd8);

/*generating gradient pattern from two colors*/

GradientPaint gp = new GradientPaint( 0, 0, color1, 0, h, color2 );

g2d.setPaint( gp ); //set grdient color to graphics2D object

g2d.fillRect( 0, 0, w, h );//feeling color

setOpaque( false );

//Generating Titleborder

TitledBorder title;

title= BorderFactory.createTitledBorder(new LineBorder(new Color(0,51,204), 2, true), null, javax.swing.border.TitledBorder.LEFT, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Arial", 0, 16), Color.BLACK);

super.setBorder(title); //appling border to JPanel

super.paintComponent( g );

setOpaque( true );

}

}

Beauty of this code: Just drag this class file from the list of project file and drop it on window form or frame. It will directly draw a panel with gradient color and border.

You can change color of gradient pattern by changing the parameter passed in Color.

Gradient pattern can also of different type as shown below

With this same concept you can create class for any component with appropriate changes. Just remember to change super class when you changes the component.

Example: for JButton, class declaration will be:

public class MyGradientJButton extends JButton

For different properties of component you can refer all time favorite Java Docs.