Java Server Pages

Java server pages is a technology that provides simplified, fast way to create dynamic web content. JSP Technology enables rapid development of web based applications that are server and platform independent. The technology allows Java code and other predefined actions to be embedded into static content.
JSP adds tags called JSP actions to be used to invoke built in functionality. The technology also allows building of JSP tag libraries which act as extension to existing HTML or XML tags.
JSP's are compiled into Java Servlets by the Java Compiler.

Patch Utils

Utilities to work with patches are patchutils. The utilities are :

1. combinediff : create a single patch from two incremental patches
2. filterdiff : filters or excludes diffs from a diff file
3. fixcvsdiff : fixes the diff files created by cvs that patch misinterprets
4. grepdiff : shows which files are modified by a patch matching a regex
5. interdiff :shows differences between two unified diff files
6. lsdiff :shows which files are modified by a particular patch
7. rediff : fixes offsets and counts of a handedited diff
8. splitdiff : seperates out two incremental patches
   

CVSps

CVSps is a program for generating patchset information from the cvs repository. Patchset is a list of changes made to a set of files for a single cvs commit command. This gives the bigger picture of evolution of a cvs project.

History of committed patch sets can be viewed in terms of author, date of commit, files affected , branches affected.

There can be a diff taken for a particular patchset. It is equivalent to tagging before and after each commit

Big Endian and Little Endian

In Big Endian system the most significant value is stored first in memory i.e in the lower order memory address.

In Little Endian system the least significant value is stored first i.e in the lower order memory address.

It occurs at byte level and can also extend to bit level within each byte.

Shared Memory Concept

In Hardware :
A single RAM is shared by many CPU's in a multi processing environment.


In Software :
Shared Memory in software is a method of interprocess communication. This is a method of exchanging data between different processes. One process will create an area in RAM which other processes can access.Both the processes can access the same memory in the same way as they access regular memory, it is faster.

Storage Virtualisation

Virtualisation is the pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. Storage Virtualisation is commonly used in Storage Area Network (SAN). The management of storage devices can be tedious and time consuming. Storage virtualisation helps the storage administrator perform the tasks of backup, archiving, and recovery more easily, and in less time by disguising the actual complexity of the SAN. Users can implement virtualisation with software applications or by using hardware and software hybrid appliances. The technology can be placed on different levels of a storage area network.

Ultra 3 and Ultra 2

Ultra3 SCSI will differ in five key areas from Ultra2 SCSI, according to STA officials.

First, transition clocking doubles data throughput to 160 megabytes per second. This is done by sending two pieces of data per clock pulse instead of one, thereby doubling the throughput without increasing the processor's clock speed.

Cyclic redundancy check will improve data-transmission reliability via an enhanced error-catching scheme.

Domain validation lets the host and device communicate to find the optimal data speed, and identifies the topology and configuration of the SCSI bus.

The other new features include packetization for transferring multiple commands and threads of data per cycle, and quick arbitration select to reduce disconnect and reconnect time on the bus.

Ultra3 SCSI will be backward-compatible with Ultra2 SCSI, allowing Ultra2 SCSI devices to connect to the bus without affecting performance.