1. INTRODUCTION

The term DDoS whistles past whenever cyber-activism rears up its head en-masse.

These kind of attacks make international headlines because of multiple reasons.

The issues that jumpstart those DDoS attacks are often controversial or highly

political. Since a large number of regular users are affected by the attacks, it’s an

issue that plays with the people.

Perhaps most importantly, a lot of people don’t know what constitutes a DDoS

attack. Despite its rising frequency, looking at the paper’s headlines, DDoS attacks

can be anything from digital vandalism to fully-fledged cyber-terrorism.

So what does a DDoS, or Distributed Denial of Service attack entail? How does it

work, and how does it affect the intended target and its users? These are important

questions, and  this is what we’re going to be focusing on in this instance

of MakeUseOf Explains.

Denial Of Service

Before we tackle the issue of DDoS, or Distributed Denial of Service attacks, let’s

look at the larger group of Denial of Service (DoS) issues.

Denial of Service is a broad issue. Simply put, a website experiences DoS issues

when it is no longer able to service its regular users. When too many people flock

to Twitter, the Fail Whale pops up, indicating that the website has reached and

passed maximum capacity. In essence, Twitter experiences DoS.

Most of the time, these issues are instigated without malicious intent. A large

website links to a small website, which isn’t built for the same level of traffic.

1.3 ORGANIZATION PROFILE

COMPANY PROFILE

Every career aspiring student wants to study to get a job. ELMAQ focusses to support a student

to complete his / her degree so as to get a job. ELMAQ academic support solutions enhance the

employability to bridge the ever widening Academics-Industry divide.

ELMAQ launched EdCademy, the academic support programme for Engineering, and

Management students to provide the much needed support for the student to complete a degree

so as to get a job. Under this programme, ELMAQ conducts Promptive Metrics based Learning

(PML) methods to enhance the performance of students in their semester exams so that their

placement prospects become better as they move to final year campus programmes. EdCademy

at the outset offers three engines of support viz., Learning Engine (LE), Assessment Engine

(AE), and Placement Engine (PE).

EdCademy assures a better student’s performance rating in their core degree subjects and

assessment essentials. This is achieved by continuous assessments that can be forced upon to

every student by the concerned HoD by unlimited access to EdCademy’s Learning Engine (LE).

Further, before the semester exam, a student can attempt many model papers of a particular

subject which the student feels tough to pass or score high through the Assessment Engine (AE)

of EdCademy. Final year students can also access for unlimited job positions through Placement

Engine (PE) of EdCademy by which virtually an e-campus interview can be organized which

could land a student in a job offer much before he / she completes the course.

EdCademy is planned for other Universities in other states as well. EdCademy is well supported

by EdClass, a product that makes a student to meet a tutor in a virtual class network (VCN)to

clarify doubts and also to get quick lectures on important and difficult topics. There will be both

live and pre-recorded sessions in EdClass.

EdCademy with EdClass is sure to simplify the process of passing exams and getting degree with

better grades. Students with EdCademy of ELMAQ can look for right placements with clients

already getting the information and screening them for their performance which are given as

footprints by the LAMPS system seamlessly in web network.

About ELMAQELMAQ is World's first 4th generation education company that uses technology to efficiently

synchronize manpower demand and supply in number and skills right from development to

deployment. The size of India's addressable market, favorable demography, growing acceptance

of technology-aided learning, and ELMAQ innovative Humanware Education And Deployment

System (HEADS) coupled with its trademarked content enable rapid growth. Its business model

is scalable nationally and internationally.

ELMAQ Softsystems Limited is incepted in Mar 1998 as ELMAQ Softsystems P Ltd., with an

objective of providing niche training solutions, customised software solutions, and placement

consulting on contract as well as permanent basis to both Corporate and Institutional clients. The

company successfully provided staffing solutions to premier clients during 2002 to 2004 viz., TI

Group, TVS Group, Office Tiger, KSB Pumps, Infosys Technologies, HCL Technologies,

Shasun Chemicals, Hexaware Technologies, Ashok Leyland, Seshasayee Paper & Boards among

others. ELMAQ acquired ELMAQ EDUCATION, leading IT Training brand in the South in the

year 2007 to move aggressively in Education & Training space. ELMAQ employs e-learning and

has patented the education models which seamlessly control the complete learning life-cycle of a

student from development to deployment in a web controlled framework. ELMAQ holds

copyrighted e-contents covering over a dozen domains and verticals.

ELMAQ is promoted by Mr. S. Giridharan, as senior technocrat of Indian IT space who is a

pioneer in Job oriented education of 90's. He has over 2 decades of experience in Education

having been instrumental in the success of SSI and Radiant education brands. Giridharan later

led ELMAQ education brand and subsequently sold to ELMAQ and merged all the businesses

under ELMAQ.

ELMAQ provides job linked next generation education through Integrated Learning Model

(ILM). ELMAQ EdCenters, EdCampuses, and EdCademys are partner-led and in-campus online

contact centers which are spread across India and South Asia providing education & placement

through ILM.

Offerings SCHOOLS

PRESCHOOL: Powerful and magnificent channel of 3 D animation videos

specially designed for your child. Interactive learning just a click away. A

program designed for your child keeping in mind the various levels of aspirations

from basic to advanced. Come and explore this unique interactive education

platform with your child today. With illustrations in the form of stories, games,

quizzes and more..your child will find it engaging and you useful. Enjoy, explore

and measure your child's development with interesting and captivating graphics

like never before.

PRIMARY: Powerful and magnificent channel of 3 D animation videos specially

designed for your child. Interactive learning just a click away. A program

designed for your child keeping in mind the various levels of aspirations from

basic to advanced. Come and explore this unique interactive education platform

with your child today. With illustrations in the form of stories, games, quizzes and

more. Your child will find it engaging and you useful. Enjoy, explore and

measure your child's development with interesting and captivating graphics like

never before.

MIDDLE: The best way to build a Nation is at Foundation The SMART C.A.P

program - Learning Concepts.Application and Problem solving. Lays solid

foundation for your preparation for Olympaids/NTSE and similar exams.

SECONDARY: ELMAQ is fully cognizant of your problems of getting the

expert tutor, wasting more of your productive time in travelling, paying high fees,

and still scoring less marks in your relentless pursuit to look for a perfect tuition

support for your subjects.Our solution is to connect you to expert tutors live from

the comfort of your home at a fraction of the tuition fee that you are paying or

will be paying.

HIGHER SECONDARY:

TEST PREP

IITJEE: Our unique program provides the following contents to prepare you

adequately for the rigors of the IITJEE exam:

i. 81 Exhaustive chapters covering all topics prescribed for IITJEE.

ii. 2500+ videos containing lectures by senior professors and top IITians

covering everything from the very basic fundamentals and tips, tricks and

shortcut methods to help you solve advanced level IIT JEE Problems.

iii. Exposure to about 10000+ unique problems spread over the IITJEE

syllabus

iv. tate-of-the-Art Assessment Engine with an extensive online database of

thousands of questions exactly on the level of IITJEE examination to build

your speed and accuracy thereby ensuring nothing is left to chance

v. 20 hours of access to IITJEE learning module and Assessment Engine.

AIEEE: Our unique program provides the following contents to prepare you

adequately for the rigors of the AIEEE exam:

i. 60 chapters spanning all topics in AIEEE across physics, chemistry and

mathematics

ii. 1400+ videos containing lectures by senior professors covering everything

from the very basic fundamentals and tips, tricks and shortcut methods to

help you solve advanced level AIEEE Problems.

iii. Exposure to about 5000+ unique problems spread over the AIEEE

syllabus

iv. State-of-the-Art Assessment Engine with an extensive online database of

thousands of questions exactly on the level of AIEEE examination to build

your speed and accuracy thereby ensuring nothing is left to chance.

v. Get access to AIEEE learning module and Assessment Engine.

OLYMPAID: The Central Board of Secondary Education conducts the National

Informatics Olympiad in collaboration with the Indian Association for Research

in Computing Science (IARCS), Mumbai, across the country and abroad. The

examination which is held in two stages is open to all the students of classes VIII

to XII studying in CBSE schools as well as other Boards in the country. At

lampsglow we believe the best way to build a Nation is at Foundation. The

SMART C.A.P program - Learning Concepts. Application and Problem solving.

The program lays a solid foundation for your child’s preparation for Olympaids

and similar exams.

NTSE: NCERT awards 1000 Scholarships to the talented students of Class VIII

each year through its National Talent Search Scheme and then nurture the talent

by way of providing financial assistance in the form of both monthly scholarship

and annual book grant. At lampsglow we believe the best way to build a Nation is

at Foundation. The SMART C.A.P program - Learning Concepts.Application and

Problem solving. The program lays a solid foundation for your child’s preparation

for NTSE and similar exams.

UNDERGRADUATE/POST GRADUATE

IT SKILLS: ELMAQ brings 7 IT courses that matter most to the studies of an

undergraduate or anyone looking to enhance their career at every stage of growth.

To access all and read through those 7 star courses viz., Computer Fundamentals,

MS-Office, C, C++, Java, Softskills, and Numerical Ability and more.

ENGINEERING STUDY: Taking education to your door steps. For all those

students looking at improving and enhancing their academic endeavors –

ELMAQ offers video lessons that enhance the quality of your revisions and re

revisions. Revisions that are the the most crucial part of exam preparation, are just

a click away. Take the lessons anytime, anywhere at your convenience.

ENGINEERING PREP: For aspiring Engineers of Anna University and All

India Engineering exams can pass your ANNA UNIVERSITY Engineering

Semester or Engineering exams easily by scoring high marks. ELMAQ offers

unlimited Access to MODEL TEST PAPERS through our online ELMAQ

LAMPSGLOW anywhere, anytime to clear your arrears and to look for careers !

"Practice until you perfect - try it and experience the perfection that you so much

wanted. Appear in your exams with greater confidence. Engineering support tests

has practice papers just for that."

PartnersA Distributor is appointed for each postal pin code. Distributor is authorized to sell all products

displayed under LG through dealer's network. Distributor can enter LG site and create his/her

own login under the distributor’s column at no cost basis which will be exclusively owned by the

distributor. The entry Fee for a distributor per pin code is nominal considering the marketing

support they would get in their region from us. A Distributor gets the edcredits in his/her login

and also in his mobile phone as registered in LG.

The distributor then appoints Dealers under his area of operation viz: the pin code for which the

distributor has paid. A distributor has the freedom to appoint as many dealers as possible in the

said pin code . Upon receiving payment from dealers , a distributor has to transfer part of

EdCredits as agreed to the dealer which can done through by transferring the same from

distributor’s login to dealer’s login.

A distributor can sell the stocks to none other than registered and paid up dealers.

Payment towards Edcredit transfer paid by dealer to distributor.

Clients BenefitsIndustry that benefits out of HEADS model is wide. Both IT and non-IT verticals and domains

are addressed. The divide between the academics and industry is ever widening especially after

India is projected as a sole source for humanware in Information Technology sector. Institutions

focus so much on IT that core industry suffers from lack of qualified and trained resources.

ELMAQ as a strategy focuses in generating competent fresher for non-IT domains upto 70% of

its business. It is expected that a lot of support would come from the student resources for non-IT

positions considering the fact that the core industries pay-packs are better and the student's

knowledge levels are low at the moment about non-IT opportunities. Further the HEADS model

is strictly automated upto a job offer after a strict training and assessment.

A client company, as industry, is always looking at employable manpower resource as a fresher

at volumes. With ELMAQ HEADS model, the client company can breathe easy and plan the

project schedules better with pre-determined lead time in a proactive way. The LAMPS portal

has its entry point for every such client who can enter their preferences, candidate's background,

curriculum essentials with assessment criteria, and commit on a defined job offers.

With rupee appreciating, it may sound interesting for companies to look into our one-stop-shop

solution of providing them with the exact set of their dream resources by taking care of the

following:

The exact requirements of fresher and the lead-time before they have to be inducted into

your actual project

Entry-level criteria

The curriculum of training to be done on them

The choice of colleges

The choice of academic excellence

The likely compensation package vs qualification and training performance

The other wish-list in terms of job-fitment straight from the college

Once clients sign-up with us with all those crucial information as your specification, they are put

up in their own digital-dashboard of what is going on from inside our automated learning system

for their selected chunks of fresher registered through our dealer gateways.

Rather their HR is directed through our digital window right from the time of the course

enrolment up to the final grading out of the regular ILT sessions with strictly controlled

assessments as per their specification What's more, the exactly matched resources to client's

specification automatically get their Job Intent on your approval from their HR who operates in

our system through a secured access login on a continuous basis.

The specifications as well as their selected resources are secured and protected till the end.

Enough flexibility is given in our model to ensure a client doesn't lose out any including the

timeframe that they are waiting for. A client may not step out of their office to achieve this 100%

matched-resource-making exercise. And all these may cost a client as low as 20% of the cost-

burn otherwise spent on their own exercise of trial-runs!

Investors

ELMAQ is India’s only company to have seamelessly integrated education and placement end-

to-end in partner based web network. ELMAQ focusses on the bottom of the pyramid, the Real

India, the hugely recession-proof market having the continuous need for affordable education

and a career growth path and guidance.

ELMAQ came out with the IPO successfully in February 2009 and is now listed in BSE and NSE,

India's premier stock exchanges. ELMAQ has consolidated its presence in Tamil Nadu as a

principal job linked e-learning solution provider through partner driven network for the masses

growing significantly from 35 odd partner centers just before IPO to 200 by Aug 2009. The

company rolled out EdCampus, EdCademy, and EdCenters with EdClass that offer learning, jobs,

metrics, and live lectures online and in-campus.

The ELMAQ strives to provide the next generation education system that matches demand-

supply in scale and quality, reach and spread, and bridges the Academics-Industry divide by

technology-led, career integrated learning framework through its last mile stretching network.

The future plans include providing end-to-end school solutions to guide every student from K-

12 to Careers. Comprehensive industry demand aligned education shall be deployed to schools.

ELMAQ believes strongly that students at their younger age are in a better position to seed with

apt careers by way of skill developments with industry orientation suiting to their aptitude and

the flair for excellence in a particular field.

2.SYSTEM REQUIREMENTS

2.1 Hardware Requirements

Processor : Dual core 2.0GHZ

Hard Disk : 320GB HDD

RAM : 2 GB RAM

Monitor : 14 LCD Monitor

Keyboard : Multimedia Keyboard

Mouse : Optical Mouse

2.2Software Requirements

Operating environment : Windows 7ultimate

Front end : c#.net

Back end : Sql Server 2005

3. SOFTWARE OVERVIEW

3.1 .NET Framework

Now that you are familiar with the major goals of the .NET Framework,

let's briefly examine its architecture. As you can see in Figure 3.2, the .NET

Framework sits on top of the operating system, which can be a few different

flavors of Windows and consists of a number of components. . NET is essentially a

system application that runs on Windows.

Fig: 3.1.1 .NET Framework

Conceptually, the CLR and the JVM are similar in that they are both runtime

infrastructures that abstract the underlying platform differences. However, while

the JVM officially supports only the Java language, the CLR supports any

language that can be represented in its Common Intermediate Language (CIL). The

JVM executes byte code, so it can, in principle, support many languages, too.

Unlike Java's byte code, though, CIL is never interpreted. Another conceptual

difference between the two infrastructures is that Java code runs on any platform

with a JVM, whereas .NET code runs only on platforms that support the CLR.

The Common Language Runtime

At the heart of the .NET Framework is the common language runtime. The

common language runtime is responsible for providing the execution environment

that code written in a .NET language runs under. The common language runtime

can be compared to the Visual Basic 6 runtime, except that the common language

runtime is designed to handle all .NET languages, not just one, as the Visual Basic

6 runtime did for Visual Basic 6. The following list describes some of the benefits

the common language runtime gives you:

Automatic memory management

Cross-language debugging

Cross-language exception handling

Full support for component versioning

Access to legacy COM components

XCOPY deployment

Robust security model

You might expect all those features, but this has never been possible using

Microsoft development tools. Figure 4.1.2 shows where the common language

runtime fits into the .NET Framework.

Fig: 3.1.2 The common language runtime.

Code written using a .NET language is known as managed code. Code that

uses anything but the common language runtime is known as unmanaged code.

The common language runtime provides a managed execution environment

for .NET code, whereas the individual runtimes of non-.NET languages provide an

unmanaged execution environment.

Inside the Common Language Runtime

The common language runtime enables code running in its execution

environment to have features such as security, versioning, memory management

and exception handling because of the way .NET code actually executes. When

you compiled Visual Basic 6 forms applications, you had the ability to compile

down to native node or p-code.

Fig: 3.1.3 Visual Basic 6 compiler options dialog.

When you compile your applications in .NET, you aren't creating anything

in native code. When you compile in .NET, you're converting your code—no

matter what .NET language you're using—into an assembly made up of an

intermediate language called Microsoft Intermediate Language.

The file format for the IL is known as PE (portable executable) format, which

is a standard format for processor-specific execution.

When a user or another component executes your code, a process occur

called just-in-time (JIT) compilation, and it's at this point that the IL is converted

into the specific machine language of the processor it's executing on. This makes it

very easy to port a .NET application to any type of operating system on any type of

processor because the IL is simply waiting to be consumed by a JIT compiler.

When the IL code is JITted into machine-specific language, it does so on an

as-needed basis. If your assembly is 10MB and the user is only using a fraction of

that 10MB, only the required IL and its dependencies are compiled to machine

language. This makes for a very efficient execution process. But during this

execution, how does the common language runtime make sure that the IL is

correct? Because the compiler for each language creates its own IL, there must be a

process that makes sure what's compiling won't corrupt the system. The process

that validates the IL is known as verification. Figure 4.1.4 demonstrates the process

the IL goes through before the code actually executes.

Fig: 3.1.4 The JIT process and verification

When code is JIT compiled, the common language runtime checks to make

sure that the IL is correct. The rules that the common language runtime uses for

verification are set forth in the Common Language Specification (CLS) and the

Common Type System (CTS).

The .NET Framework Class Library

The second most important piece of the .NET Framework is the .NET

Framework class library (FCL). As you've seen, the common language runtime

handles the dirty work of actually running the code you write. But to write the

code, you need a foundation of available classes to access the resources of the

operating system, database server, or file server. The FCL is made up of a

hierarchy of namespaces that expose classes, structures, interfaces, enumerations,

and delegates that give you access to these resources.

The Structure of a .NET Application

To understand how the common language runtime manages code execution,

you must examine the structure of a .NET application. The primary unit of a .NET

application is the assembly. An assembly is a self-describing collection of code,

resources, and metadata. The assembly manifest contains information about what

is contained within the assembly.

The assembly manifest provides:

Identity information, such as the assembly’s name and version number

A list of all types exposed by the assembly

A list of other assemblies required by the assembly

A list of code access security instructions, including permissions required by

the assembly and permissions to be denied the assembly

Each assembly has one and only one assembly manifest, and it contains all

the description information for the assembly. However, the assembly manifest can

be contained in its own file or within one of the assembly’s modules.

Compilation and Execution of a .NET Application

When you compile a .NET application, it is not compiled to binary machine

code; rather, it is converted to IL. This is the form that your deployed application

takes—one or more assemblies consisting of executable files and DLL files in IL

form. At least one of these assemblies will contain an executable file that has been

designated as the entry point for the application.

When execution of your program begins, the first assembly is loaded into

memory. At this point, the common language runtime examines the assembly

manifest and determines the requirements to run the program. It examines security

permissions requested by the assembly and compares them with the system’s

security policy. If the system’s security policy does not allow the requested

permissions, the application will not run. If the application passes the system’s

security policy, the common language runtime executes the code. It creates a

process for the application to run in and begins application execution.

The .NET Framework base class library contains the base classes that provide

many of the services and objects you need when writing your applications. The

class library is organized into namespaces. A namespace is a logical grouping of

types that perform related functions. Namespaces are logical groupings of related

classes. The namespaces in the .NET base class library are organized

hierarchically. The root of the .NET Framework is the System namespace. Other

namespaces can be accessed with the period operator. A typical namespace

construction appears as follows:

System

System.Data

System.Data.SQLClient

The first example refers to the System namespace. The second refers to the

System.Data namespace. The third example refers to the System.Data.SQLClient

namespace. Table 1.1 introduces some of the more commonly used .NET base

class namespaces.

Introduction to Object-Oriented Programming

Programming in the .NET Framework environment is done with objects.

Objects are programmatic constructs that represent packages of related data and

functionality. Objects are self-contained and expose specific functionality to the

rest of the application environment without detailing the inner workings of the

object itself. Objects are created from a template called a class. The .NET base

class library provides a set of classes from which you can create objects in your

applications. You also can use the Microsoft Visual Studio programming

environment to create your own classes. This lesson introduces you to the concepts

associated with object-oriented programming.

Objects, Members, and Abstraction

An object is a programmatic construct that represents something. In the

real world, objects are cars, bicycles, laptop computers, and so on. Each of these

items exposes specific functionality and has specific properties. In your

application, an object might be a form, a control such as a button, a database

connection, or any of a number of other constructs. Each object is a complete

functional unit, and contains all of the data and exposes all of the functionality

required to fulfill its purpose. The ability of programmatic objects to represent real-

world objects is called abstraction.

Classes Are Templates for Objects

Classes were discussed in Chapter 1 and represent user-defined reference

types. Classes can be thought of as blueprints for objects: they define all of the

members of an object, define the behavior of an object, and set initial values for

data when appropriate. When a class is instantiated, an in-memory instance of that

class is created. This instance is called an object. To review, a class is instantiated

using the New (new) keyword as follows:

Visual Basic .NET

' Declares a variable of the Widget type

Dim myWidget As Widget

' Instantiates a new Widget object and assigns it to the myWidget 

' variable

myWidget = New Widget()

When an instance of a class is created, a copy of the instance data defined by

that class is created in memory and assigned to the reference variable. Individual

instances of a class are independent of one another and represent separate

programmatic constructs.

There is generally no limit to how many copies of a single class can be

instantiated at any time. To use a real-world analogy, if a car is an object, the plans

for the car are the class. The plans can be used to make any number of cars, and

changes to a single car do not, for the most part, affect any other cars.

Objects and Members

Objects are composed of members. Members are properties, fields, methods,

and events, and they represent the data and functionality that comprise the object.

Fields and properties represent data members of an object. Methods are actions the

object can perform, and events are notifications an object receives from or sends to

other objects when activity happens in the application.

Object Models

Simple objects might consist of only a few properties, methods, and perhaps

an event or two. More complex objects might require numerous properties and

methods and possibly even subordinate objects. Objects can contain and expose

other objects as members.

Similarly, every instance of the Form class contains and exposes a Controls

collection that comprises all of the controls contained by the form. The object

model defines the hierarchy of contained objects that form the structure of an

object.

Encapsulation

Encapsulation is the concept that implementation of an object is

independent of its interface. Put another way, an application interacts with an

object through its interface, which consists of its public properties and methods. As

long as this interface remains constant, the application can continue to interact with

the component, even if implementation of the interface was completely rewritten

between versions.

Polymorphism

Polymorphism is the ability of different classes to provide different

implementations of the same public interfaces. In other words, polymorphism

allows methods and properties of an object to be called without regard for the

particular implementation of those members. There are two principal ways through

which polymorphism can be provided: interface polymorphism and inheritance

polymorphism.

Interface Polymorphism

An interface is a contract for behavior. Essentially, it defines the members a

class should implement, but states nothing at all about the details of that

implementation. An object can implement many different interfaces, and many

diverse classes can implement the same interface. All objects implementing the

same interface are capable of interacting with other objects through that interface.

Inheritance Polymorphism

Inheritance allows you to incorporate the functionality of a previously

defined class into a new class and implement different members as needed. A class

that inherits another class is said to derive from that class, or to inherit from that

class. A class can directly inherit from only one class, which is called the base

class. The new class has the same members as the base class, and additional

members can be added as needed. Additionally, the implementation of base

members can be changed in the new class by overriding the base class

implementation. Inherited classes retain all the characteristics of the base class and

can interact with other objects as though they were instances of the base class.

C#.Net:

C# is an elegant and type-safe object-oriented language that enables

developers to build a variety of secure and robust applications that run on the .NET

Framework. You can use C# to create traditional Windows client applications,

XML Web services, distributed components, client-server applications, database

applications, and much, much more. Visual C# provides an advanced code editor,

convenient user interface designers, integrated debugger, and many other tools to

make it easier to develop applications based on version 4.0 of the C# language and

version 4.0 of the .NET Framework.

C# syntax is highly expressive, C# makes it easy to develop software components

through several innovative language constructs, including the following:

Encapsulated method signatures called delegates, which enable type-safe event

notifications.

Properties, which serve as accessors for private member variables.

Attributes, which provide declarative metadata about types at run time.

Inline XML documentation comments.

Language-Integrated Query (LINQ) which provides built-in query capabilities

across a variety of data sources.

yet it is also simple and easy to learn. The curly-brace syntax of C# will be

instantly recognizable to anyone familiar with C, C++ or Java. Developers who

know any of these languages are typically able to begin to work productively in C#

within a very short time. C# syntax simplifies many of the complexities of C++

and provides powerful features such as nullable value types, enumerations,

delegates, lambda expressions and direct memory access, which are not found in

Java. C# supports generic methods and types, which provide increased type safety

and performance, and iterators, which enable implementers of collection classes to

define custom iteration behaviors that are simple to use by client code. Language-

Integrated Query (LINQ) expressions make the strongly-typed query a first-class

language construct.

As an object-oriented language, C# supports the concepts of encapsulation,

inheritance, and polymorphism. All variables and methods, including the Main

method, the application's entry point, are encapsulated within class definitions. A

class may inherit directly from one parent class, but it may implement any number

of interfaces. Methods that override virtual methods in a parent class require the

override keyword as a way to avoid accidental redefinition. In C#, a struct is like a

lightweight class; it is a stack-allocated type that can implement interfaces but does

not support inheritance. The C# build process is simple compared to C and C++

and more flexible than in Java. There are no separate header files, and no

requirement that methods and types be declared in a particular order. A C# source

file may define any number of classes, structs, interfaces, and events.

C# programs run on the .NET Framework, an integral component of

Windows that includes a virtual execution system called the common language

runtime (CLR) and a unified set of class libraries. The CLR is the commercial

implementation by Microsoft of the common language infrastructure (CLI), an

international standard that is the basis for creating execution and development

environments in which languages and libraries work together seamlessly.

Source code written in C# is compiled into an intermediate language (IL) that

conforms to the CLI specification. The IL code and resources, such as bitmaps and

strings, are stored on disk in an executable file called an assembly, typically with

an extension of .exe or .dll. An assembly contains a manifest that provides

information about the assembly's types, version, culture, and security requirements.

When the C# program is executed, the assembly is loaded into the CLR, which

might take various actions based on the information in the manifest. Then, if the

security requirements are met, the CLR performs just in time (JIT) compilation to

convert the IL code to native machine instructions. The CLR also provides other

services related to automatic garbage collection, exception handling, and resource

management. Code that is executed by the CLR is sometimes referred to as

"managed code," in contrast to "unmanaged code" which is compiled into native

machine language that targets a specific system. The following diagram illustrates

the compile-time and run-time relationships of C# source code files, the .NET

Framework class libraries, assemblies, and the CLR.

Distinguishing features

C# supports strongly typed implicit variable declarations with the keyword

var, and implicitly typed arrays with the keyword new[] followed by a

collection initialize.

Meta programming via C# attributes is part of the language. Many of these

attributes duplicate the functionality of GCC's and VisualC++'s platform-

dependent preprocessor directives.

Like C++, and unlike Java, C# programmers must use the keyword virtual to

allow methods to be overridden by subclasses.

Extension methods in C# allow programmers to use static methods as if they

were methods from a class's method table, allowing programmers to add

methods to an object that they feel should exist on that object and its

derivatives.

The type dynamic allows for run-time method binding, allowing for

JavaScript like method calls and run-time object composition.

C# has strongly typed and verbose function pointer support via the keyword

delegate.

The C# languages does not allow for global variables or functions. All

methods and members must be declared within classes. Static members of

public classes can substitute for global variables and functions.

Local variables cannot shadow variables of the enclosing block, unlike C

and C++.

A C# namespace provides the same level of code isolation as a Java package

or a C++ namespace, with very similar rules and features to a package.

C# supports a strict Boolean data type, bool. Statements that take conditions,

such as while and if, require an expression of a type that implements the true

operator, such as the Boolean type. While C++ also has a Boolean type, it

can be freely converted to and from integers, and expressions such as if(a)

require only that a is convertible to bool, allowing a to be an int, or a pointer.

C# disallows this "integer meaning true or false" approach, on the grounds

that forcing programmers to use expressions that return exactly bool can

prevent certain types of common programming mistakes in C or C++ such

as if (a = b) (use of assignment = instead of equality ==).

Categories of data types

CTS separates data types into two categories.

1. Value types

2. Reference types

Instances of value types do not have referential identity nor referential comparison

semantics - equality and inequality comparisons for value types compare the actual

data values within the instances, unless the corresponding operators are

overloaded. Value types are derived from System.ValueType, always have a

default value, and can always be created and copied. Some other limitations on

value types are that they cannot derive from each other (but can implement

interfaces) and cannot have an explicit default (parameter less) constructor.

Examples of value types are all primitive types, such as int (a signed 32-bit

integer), float (a 32-bit IEEE floating-point number), char (a 16-bit Unicode code

unit), and System.DateTime (identifies a specific point in time with nanosecond

precision). Other examples are enum (enumerations) and struct (user defined

structures).

In contrast, reference types have the notion of referential identity - each instance of

a reference type is inherently distinct from every other instance, even if the data

within both instances is the same. This is reflected in default equality and

inequality comparisons for reference types, which test for referential rather than

structural equality, unless the corresponding operators are overloaded (such as the

case for System. String). In general, it is not always possible to create an instance

of a reference type, nor to copy an existing instance, or perform a value

comparison on two existing instances, though specific reference types can provide

such services by exposing a public constructor or implementing a corresponding

interface (such as ICloneable or Incomparable). Examples of reference types are

object (the ultimate base class for all other C# classes), System. String (a string of

Unicode characters), and System. Array (a base class for all C# arrays).

Both type categories are extensible with user-defined types.

Code comments

C# utilizes a double slash (//) to indicate the rest of the line is a comment.

This is inherited from c++

public class Foo

{

// a comment

public static void Bar(int first Aram) {} // also a comment

}

Multi-line comments can start with slash-asterisk (/*) and end asterisk-slash

(*/). This is inherited from standard C. public class Foo

{

/* A Multi-Line

comment */

public static void Bar(int firstParam) {}

}

A C# developer with strong severside and multithreading skills is required to join a

leading investment banks front office FX team to work on an options pricing desk.

Declaration

Instantiation

Invocation

A very basic example (SimpleDelegate1.cs):

using System;

namespace Akadia.BasicDelegate

{

    // Declaration

    public delegate void SimpleDelegate();

    class Test Delegate

    {

        public static void MyFunc()

        {

            Console.WriteLine("I was called by delegate ...");

        }

        public static void Main()

        {

            // Instantiation

            SimpleDelegate simpleDelegate = new SimpleDelegate(MyFunc);

            // Invocation

            simpleDelegate();

        }

    }

}

3.2 Sql Server 2005

Microsoft SQL Server is a relational database management system

developed by Microsoft. As a database, it is a software product whose primary

function is to store and retrieve data as requested by other software applications, be

it those on the same computer or those running on another computer across a

network (including the Internet). There are at least a dozen different editions of

Microsoft SQL Server aimed at different audiences and for different workloads

(ranging from small applications that store and retrieve data on the same computer,

to millions of users and computers that access huge amounts of data from the

Internet at the same time). Its primary query languages are T-SQL and ANSI SQL.

SQL Server 2005

SQL Server 2005 (formerly codenamed "Yukon") released in October 2005. It

included native support for managing XML data, in addition to relational data. For

this purpose, it defined an xml data type that could be used either as a data type in

database columns or as literals in queries. XML columns can be associated with

XSD schemas; XML data being stored is verified against the schema. XML is

converted to an internal binary data type before being stored in the database.

Specialized indexing methods were made available for XML data. XML data is

queried using Query; SQL Server 2005 added some extensions to the T-SQL

language to allow embedding XQuery queries in T-SQL. In addition, it also

defines a new extension to XQuery, called XML DML that allows query-based

modifications to XML data. SQL Server 2005 also allows a database server to be

exposed over web services using Tabular Data Stream (TDS) packets encapsulated

within SOAP protocol requests. When the data is accessed over web services,

results are returned as XML.

SQL Server 2005 introduced "MARS" (Multiple Active Results Sets), a method of

allowing usage of database connections for multiple purposes.

Microsoft makes SQL Server available in multiple editions, with different feature

sets and targeting different users.

Mainstream editions

Datacenter

SQL Server 2008 R2 Datacenter is the full-featured edition of SQL Server

and is designed for datacenters that need the high levels of application

support and scalability. It supports 256 logical processors and virtually

unlimited memory. Comes with Stream Insight Premium edition.] The

Datacenter edition has been retired in SQL Server 2012; all its features are

available in SQL Server 2012 Enterprise Edition.

Enterprise

SQL Server Enterprise Edition includes both the core database engine and

add-on services, with a range of tools for creating and managing a SQL

Server cluster. It can manage databases as large as 524 petabytes and

address 2 terabytes of memory and supports 8 physical processors. SQL

2012 Edition supports 160 Physical Processors]

Standard

SQL Server Standard edition includes the core database engine, along with

the stand-alone services. It differs from Enterprise edition in that it supports

fewer active instances (number of nodes in a cluster) and does not include

some high-availability functions such as hot-add memory (allowing memory

to be added while the server is still running), and parallel indexes.

Web

SQL Server Web Edition is a low-TCO option for Web hosting.

Business Intelligence

Introduced in SQL Server 2012 and focusing on Self Service and Corporate

Business Intelligence. It includes the Standard Edition capabilities and

Business Intelligence tools: PowerPivot, Power View, the BI Semantic

Model, Master Data Services, Data Quality Services and xVelocity in-

memory analytics

Workgroup

SQL Server Workgroup Edition includes the core database functionality but

does not include the additional services. Note that this edition has been

retired in SQL Server 2012

Express

SQL Server Express Edition is a scaled down, free edition of SQL Server,

which includes the core database engine. While there are no limitations on

the number of databases or users supported, it is limited to using one

processor, 1 GB memory and 4 GB database files (10 GB database files

from SQL Server Express 2008 R2) It is intended as a replacement for

MSDE. Two additional editions provide a superset of features not in the

original Express Edition. The first is SQL Server Express with Tools,

which includes SQL Server Management Studio Basic. SQL Server

Express with Advanced Services adds full-text search capability and

reporting services.

[edit] Specialized editions

Azure

Microsoft SQL Azure Database is the cloud-based version of Microsoft SQL

Server, presented as software as a service on Azure Services Platform.

Compact (SQL CE)

The compact edition is an embedded database engine. Unlike the other

editions of SQL Server, the SQL CE engine is based on SQL Mobile

(initially designed for use with hand-held devices) and does not share the

same binaries. Due to its small size (1 MB DLL footprint), it has a markedly

reduced feature set compared to the other editions. For example, it supports

a subset of the standard data types, does not support stored procedures or

Views or multiple-statement batches (among other limitations). It is limited

to 4 GB maximum database size and cannot be run as a Windows service,

Compact Edition must be hosted by the application using it. The 3.5 version

includes supports ADO.NET Synchronization Services. SQL CE does not

support ODBC connectivity, unlike SQL Server proper.

Developer

SQL Server Developer Edition includes the same features as SQL Server

2012 Enterprise Edition, but is limited by the license to be only used as a

development and test system, and not as production server. This edition is

available to download by students free of charge as a part of Microsoft's

DreamSpark program.

Embedded (SSEE)

SQL Server 2005 Embedded Edition is a specially configured named

instance of the SQL Server Express database engine which can be accessed

only by certain Windows Services.

Evaluation

SQL Server Evaluation Edition, also known as the Trial Edition, has all the

features of the Enterprise Edition, but is limited to 180 days, after which the

tools will continue to run, but the server services will stop.

Fast Track

SQL Server Fast Track is specifically for enterprise-scale data warehousing

storage and business intelligence processing, and runs on reference-

architecture hardware that is optimized for Fast Track.

LocalDB

Introduced in SQL Server Express 2012, LocalDB is a minimal, on-demand,

version of SQL Server that is designed for application developers. It can also

be used as an embedded database/.

Parallel Data Warehouse (PDW)

A massively parallel processing (MPP) SQL Server appliance optimized for

large-scale data warehousing such as hundreds of terabytes]

Datawarehouse Appliance Edition

Pre-installed and configured as part of an appliance in partnership with Dell

& HP base on the Fast Track architecture. This edition does not include SQL

Server Integration Services, Analysis Services, or Reporting Services.

Architecture

The protocol layer implements the external interface to SQL Server. All operations

that can be invoked on SQL Server are communicated to it via a Microsoft-defined

format, called Tabular Data Stream (TDS). TDS is an application layer protocol,

used to transfer data between a database server and a client. Initially designed and

developed by Sybase Inc. for their Sybase SQL Server relational database engine

in 1984, and later by Microsoft in Microsoft SQL Server, TDS packets can be

encased in other physical transport dependent protocols, including TCP/IP, Named

pipes, and Shared memory. Consequently, access to SQL Server is available over

these protocols. In addition, the SQL Server API is also exposed over web

services.

Data storage

Data storage is a database, which is a collection of tables with typed columns. SQL

Server supports different data types, including primary types such as Integer,

Float, Decimal, Char (including character strings), Varchar (variable length

character strings), binary (for unstructured blobs of data), Text (for textual data)

among others. The rounding of floats to integers uses either Symmetric Arithmetic

Rounding or Symmetric Round Down (Fix) depending on arguments: SELECT

Round(2.5, 0) gives 3.

Microsoft SQL Server also allows user-defined composite types (UDTs) to be

defined and used. It also makes server statistics available as virtual tables and

views (called Dynamic Management Views or DMVs). In addition to tables, a

database can also contain other objects including views, stored procedures, indexes

and constraints, along with a transaction log. A SQL Server database can contain a

maximum of 231 objects, and can span multiple OS-level files with a maximum file

size of 260 bytes.[39] The data in the database are stored in primary data files with an

extension .mdf. Secondary data files, identified with a .ndf extension, are used to

store optional metadata. Log files are identified with the .ldf extension.

Storage space allocated to a database is divided into sequentially numbered pages,

each 8 KB in size. A page is the basic unit of I/O for SQL Server operations. A

page is marked with a 96-byte header which stores metadata about the page

including the page number, page type, free space on the page and the ID of the

object that owns it. Page type defines the data contained in the page - data stored in

the database, index, allocation map which holds information about how pages are

allocated to tables and indexes, change map which holds information about the

changes made to other pages since last backup or logging, or contain large data

types such as image or text. While page is the basic unit of an I/O operation, space

is actually managed in terms of an extent which consists of 8 pages. A database

object can either span all 8 pages in an extent ("uniform extent") or share an extent

with up to 7 more objects ("mixed extent"). A row in a database table cannot span

more than one page, so is limited to 8 KB in size. However, if the data exceeds 8

KB and the row contains Varchar or Varbinary data, the data in those columns are

moved to a new page (or possibly a sequence of pages, called an Allocation unit)

and replaced with a pointer to the data.

For physical storage of a table, its rows are divided into a series of partitions

(numbered 1 to n). The partition size is user defined; by default all rows are in a

single partition. A table is split into multiple partitions in order to spread a database

over a cluster. Rows in each partition are stored in either B-tree or heap structure.

If the table has an associated index to allow fast retrieval of rows, the rows are

stored in-order according to their index values, with a B-tree providing the index.

The data is in the leaf node of the leaves, and other nodes storing the index values

for the leaf data reachable from the respective nodes. If the index is non-clustered,

the rows are not sorted according to the index keys. An indexed view has the same

storage structure as an indexed table. A table without an index is stored in an

unordered heap structure. Both heaps and B-trees can span multiple allocation

units.[53]

Buffer management

SQL Server buffers pages in RAM to minimize disc I/O. Any 8 KB page can be

buffered in-memory, and the set of all pages currently buffered is called the buffer

cache. The amount of memory available to SQL Server decides how many pages

will be cached in memory. The buffer cache is managed by the Buffer Manager.

Either reading from or writing to any page copies it to the buffer cache. Subsequent

reads or writes are redirected to the in-memory copy, rather than the on-disc

version. The page is updated on the disc by the Buffer Manager only if the in-

memory cache has not been referenced for some time. While writing pages back to

disc, asynchronous I/O is used whereby the I/O operation is done in a background

thread so that other operations do not have to wait for the I/O operation to

complete. Each page is written along with its checksum when it is written. When

reading the page back, its checksum is computed again and matched with the

stored version to ensure the page has not been damaged or tampered with in the

meantime.

Concurrency and locking

SQL Server allows multiple clients to use the same database concurrently. As such,

it needs to control concurrent access to shared data, to ensure data integrity—when

multiple clients update the same data, or clients attempt to read data that is in the

process of being changed by another client. SQL Server provides two modes of

concurrency control: pessimistic concurrency and optimistic concurrency. When

pessimistic concurrency control is being used, SQL Server controls concurrent

access by using locks. Locks can be either shared or exclusive. Exclusive lock

grants the user exclusive access to the data—no other user can access the data as

slong as the lock is held. Shared locks are used when some data is being read—

multiple users can read from data locked with a shared lock, but not acquire an

exclusive lock. The latter would have to wait for all shared locks to be released.

Locks can be applied on different levels of granularity—on entire tables, pages, or

even on a per-row basis on tables. For indexes, it can either be on the entire index

or on index leaves. The level of granularity to be used is defined on a per-database

basis by the database administrator. While a fine grained locking system allows

more users to use the table or index simultaneously, it requires more resources. So

it does not automatically turn into higher performing solution. SQL Server also

includes two more lightweight mutual exclusion solutions—latches and spinlocks

—which are less robust than locks but are less resource intensive. SQL Server uses

them for DMVs and other resources that are usually not busy. SQL Server also

monitors all worker threads that acquire locks to ensure that they do not end up in

deadlocks—in case they do, SQL Server takes remedial measures, which in many

cases is to kill one of the threads entangled in a deadlock and rollback the

transaction it started.[39] To implement locking, SQL Server contains the Lock

Manager. The Lock Manager maintains an in-memory table that manages the

database objects and locks, if any, on them along with other metadata about the

lock. Access to any shared object is mediated by the lock manager, which either

grants access to the resource or blocks it.

SQL Server also provides the optimistic concurrency control mechanism, which is

similar to the multiversion concurrency control used in other databases. The

mechanism allows a new version of a row to be created whenever the row is

updated, as opposed to overwriting the row, i.e., a row is additionally identified by

the ID of the transaction that created the version of the row. Both the old as well as

the new versions of the row are stored and maintained, though the old versions are

moved out of the database into a system database identified as Tempdb. When a

row is in the process of being updated, any other requests are not blocked (unlike

locking) but are executed on the older version of the row. If the other request is an

update statement, it will result in two different versions of the rows—both of them

will be stored by the database, identified by their respective transaction IDs.

Data retrieval

The main mode of retrieving data from an SQL Server database is querying for it.

The query is expressed using a variant of SQL called T-SQL, a dialect Microsoft

SQL Server shares with Sybase SQL Server due to its legacy. The query

declaratively specifies what is to be retrieved. It is processed by the query

processor, which figures out the sequence of steps that will be necessary to retrieve

the requested data. The sequence of actions necessary to execute a query is called a

query plan. There might be multiple ways to process the same query. For example,

for a query that contains a join statement and a select statement, executing join on

both the tables and then executing select on the results would give the same result

as selecting from each table and then executing the join, but result in different

execution plans. In such case, SQL Server chooses the plan that is expected to

yield the results in the shortest possible time. This is called query optimization and

is performed by the query processor itself.

SQL Server includes a cost-based query optimizer which tries to optimize on the

cost, in terms of the resources it will take to execute the query. Given a query, then

the query optimizer looks at the database schema, the database statistics and the

system load at that time. It then decides which sequence to access the tables

referred in the query, which sequence to execute the operations and what access

method to be used to access the tables. For example, if the table has an associated

index, whether the index should be used or not - if the index is on a column which

is not unique for most of the columns (low "selectivity"), it might not be

worthwhile to use the index to access the data. Finally, it decides whether to

execute the query concurrently or not. While a concurrent execution is more costly

in terms of total processor time, because the execution is actually split to different

processors might mean it will execute faster. Once a query plan is generated for a

query, it is temporarily cached. For further invocations of the same query, the

cached plan is used. Unused plans are discarded after some time.

SQL Server also allows stored procedures to be defined. Stored procedures are

parameterized T-SQL queries, that are stored in the server itself (and not issued by

the client application as is the case with general queries). Stored procedures can

accept values sent by the client as input parameters, and send back results as output

parameters. They can call defined functions, and other stored procedures, including

the same stored procedure (up to a set number of times). They can be selectively

provided access to. Unlike other queries, stored procedures have an associated

name, which is used at runtime to resolve into the actual queries. Also because the

code need not be sent from the client every time (as it can be accessed by name), it

reduces network traffic and somewhat improves performance. Execution plans for

stored procedures are also cached as necessary Services

SQL Server also includes an assortment of add-on services. While these are not

essential for the operation of the database system, they provide value added

services on top of the core database management system. These services either run

as a part of some SQL Server component or out-of-process as Windows Service

and presents their own API to control and interact with them.

Service Broker

Used inside an instance, it is used to provide an asynchronous programming

environment. For cross instance applications, Service Broker communicates over

TCP/IP and allows the different components to be synchronized together, via

exchange of messages. The Service Broker, which runs as a part of the database

engine, provides a reliable messaging and message queuing platform for SQL

Server applications.

Replication Services

SQL Server Replication Services are used by SQL Server to replicate and

synchronize database objects, either in entirety or a subset of the objects present,

across replication agents, which might be other database servers across the

network, or database caches on the client side. Replication follows a

publisher/subscriber model, i.e., the changes are sent out by one database server

("publisher") and are received by others ("subscribers"). SQL Server supports three

different types of replication

Transaction replication

Each transaction made to the publisher database (master database) is synced

out to subscribers, who update their databases with the transaction.

Transactional replication synchronizes databases in near real time.[61]

Merge replication

Changes made at both the publisher and subscriber databases are tracked,

and periodically the changes are synchronized bi-directionally between the

publisher and the subscribers. If the same data has been modified differently

in both the publisher and the subscriber databases, synchronization will

result in a conflict which has to be resolved - either manually or by using

pre-defined policies. rowguid needs to be configured on a column if merge

replication is configured

Snapshot replication

Snapshot replication publishes a copy of the entire database (the then-

snapshot of the data) and replicates out to the subscribers. Further changes to

the snapshot are not tracked.

Analysis Services

SQL Server Analysis Services adds OLAP and data mining capabilities for SQL

Server databases. The OLAP engine supports MOLAP, ROLAP and HOLAP

storage modes for data. Analysis Services supports the XML for Analysis standard

as the underlying communication protocol. The cube data can be accessed using

MDX and LINQ queries. Data mining specific functionality is exposed via the

DMX query language. Analysis Services includes various algorithms - Decision

trees, clustering algorithm, Naive Bayes algorithm, time series analysis, sequence

clustering algorithm, linear and logistic regression analysis, and neural networks -

for use in data mining.

Reporting Services

SQL Server Reporting Services is a report generation environment for data

gathered from SQL Server databases. It is administered via a web interface.

Reporting services features a web services interface to support the development of

custom reporting applications. Reports are created as RDL files

Reports can be designed using recent versions of Microsoft Visual Studio (Visual

Studio.NET 2003, 2005, and 2008) with Business Intelligence Development

Studio, installed or with the included Report Builder. Once created, RDL files can

be rendered in a variety of formats including Excel, PDF, CSV, XML, TIFF (and

other image formats) and HTML Web Archive.

Notification Services

Originally introduced as a post-release add-on for SQL Server 2000,[71]

Notification Services was bundled as part of the Microsoft SQL Server platform

for the first and only time with SQL Server 2005. SQL Server Notification

Services is a mechanism for generating data-driven notifications, which are sent to

Notification Services subscribers. A subscriber registers for a specific event or

transaction (which is registered on the database server as a trigger); when the event

occurs, Notification Services can use one of three methods to send a message to the

subscriber informing about the occurrence of the event. These methods include

SMTP, SOAP, or by writing to a file in the filesystem Notification Services was

discontinued by Microsoft with the release of SQL Server 2008 in August 2008,

and is no longer an officially supported component of the SQL Server database

platform.

Integration Services

SQL Server Integration Services is used to integrate data from different data

sources. It is used for the ETL capabilities for SQL Server for data warehousing

needs. Integration Services includes GUI tools to build data extraction workflows

integration various functionality such as extracting data from various sources,

querying data, transforming data including aggregating, duplication and merging

data, and then loading the transformed data onto other sources, or sending e-mails

detailing the status of the operation as defined by the user.

[edit] Full Text Search Service

The SQL Server Full Text Search service architecture

SQL Server Full Text Search service is a specialized indexing and querying service

for unstructured text stored in SQL Server databases. The full text search index can

be created on any column with character based text data. It allows for words to be

searched for in the text columns. While it can be performed with the SQL LIKE

operator, using SQL Server Full Text Search service can be more efficient. Full

allows for inexact matching of the source string, indicated by a Rank value which

can range from 0 to 1000 - a higher rank means a more accurate match. It also

allows linguistic matching ("inflectional search"), i.e., linguistic variants of a word

(such as a verb in a different tense) will also be a match for a given word (but with

a lower rank than an exact match). Proximity searches are also supported, i.e., if

the words searched for do not occur in the sequence they are specified in the query

but are near each other, they are also considered a match. T-SQL exposes special

operators that can be used to access the FTS capabilities.

The Full Text Search engine is divided into two processes - the Filter Daemon

process (msftefd.exe) and the Search process (msftesql.exe). These processes

interact with the SQL Server. The Search process includes the indexer (that creates

the full text indexes) and the full text query processor. The indexer scans through

text columns in the database. It can also index through binary columns, and use

iFilters to extract meaningful text from the binary blob (for example, when a

Microsoft Word document is stored as an unstructured binary file in a database).

The iFilters are hosted by the Filter Daemon process. Once the text is extracted, the

Filter Daemon process breaks it up into a sequence of words and hands it over to

the indexer. The indexer filters out noise words, i.e., words like A, And etc., which

occur frequently and are not useful for search. With the remaining words, an

inverted index is created, associating each word with the columns they were found

in. SQL Server itself includes a Gatherer component that monitors changes to

tables and invokes the indexer in case of updates.[78]

When a full text query is received by the SQL Server query processor, it is handed

over to the FTS query processor in the Search process. The FTS query processor

breaks up the query into the constituent words, filters out the noise words, and uses

an inbuilt thesaurus to find out the linguistic variants for each word. The words are

then queried against the inverted index and a rank of their accurateness is

computed. The results are returned to the client via the SQL Server process.

SQLCMD

SQLCMD is a command line application that comes with Microsoft SQL Server,

and exposes the management features of SQL Server. It allows SQL queries to be

written and executed from the command prompt. It can also act as a scripting

language to create and run a set of SQL statements as a script. Such scripts are

stored as a .sql file, and are used either for management of databases or to create

the database schema during the deployment of a database.

SQLCMD was introduced with SQL Server 2005 and this continues with SQL

Server 2008. Its predecessor for earlier versions was OSQL and ISQL, which is

functionally equivalent as it pertains to TSQL execution, and many of the

command line parameters are identical, although SQLCMD adds extra versatility.

Visual Studio

Microsoft Visual Studio includes native support for data programming with

Microsoft SQL Server. It can be used to write and debug code to be executed by

SQL CLR. It also includes a data designer that can be used to graphically create,

view or edit database schemas. Queries can be created either visually or using

code. SSMS 2008 onwards, provides intellisense for SQL queries as well.

SQL Server Management Studio

SQL Server Management Studio is a GUI tool included with SQL Server 2005 and

later for configuring, managing, and administering all components within

Microsoft SQL Server. The tool includes both script editors and graphical tools

that work with objects and features of the server.[79] SQL Server Management

Studio replaces Enterprise Manager as the primary management interface for

Microsoft SQL Server since SQL Server 2005. A version of SQL Server

Management Studio is also available for SQL Server Express Edition, for which it

is known as SQL Server Management Studio Express (SSMSE).[80]

A central feature of SQL Server Management Studio is the Object Explorer, which

allows the user to browse, select, and act upon any of the objects within the server.

[81] It can be used to visually observe and analyze query plans and optimize the

database performance, among others SQL Server Management Studio can also be

used to create a new database, alter any existing database schema by adding or

modifying tables and indexes, or analyze performance. It includes the query

windows which provide a GUI based interface to write and execute queries.

Business Intelligence Development Studio

Business Intelligence Development Studio (BIDS) is the IDE from Microsoft used

for developing data analysis and Business Intelligence solutions utilizing the

Microsoft SQL Server Analysis Services, Reporting Services and Integration

Services. It is based on the Microsoft Visual Studio development environment but

is customized with the SQL Server services-specific extensions and project types,

including tools, controls and projects for reports (using Reporting Services), Cubes

and data mining structures (using Analysis Services) Microsoft SQL Server is a

relational database management system developed by Microsoft. As a database, it

is a software product whose primary function is to store and retrieve data as

requested by other software applications, be it those on the same computer or those

running on another computer across a network (including the Internet). There are at

least a dozen different editions of Microsoft…

.

4.SYSTEM ANALYSIS

4.1 EXISTING SYSTEM:

Previous work focused on extracting DDoS attack features, and was

followed by detecting and filtering DDoS attack packets by the known features.

However, these Methods cannot actively detect DDoS attacks. Flash crowds are

unexpected, but legitimate, dramatic surges of access to a server, such as breaking

news. The work of discriminating DDoS attacks from flash crowds has been

explored for around a decade. This method involves human responses and can be

annoying to users.

4.2 PROPOSED SYSTEM:

The current most popular defence against flash crowd attacks is the use of

graphical puzzles to differentiate between humans and bots. This method involves

human responses and can be annoying to users. Bots are caught by honeypots and

analyzed thoroughly via inverse engineering techniques. The proposed algorithm

works independently of specific DDoS flooding attack genres. Therefore, it is

effective against unknown forthcoming flooding attacks. The proposed correlation

coefficient-based method is delay proof. This property is very effective against

explicit random delay insertion among attack flows. We used the flow correlation

coefficient as a metric to measure the similarity among suspicious flows to

differentiate DDoS attacks from genuine flash crowds.

4.3 FEASIBILITY STUDY

Feasibility study has three aspects. They are

5.3.1 Technical Feasibility

5.3.2 Economic Feasibility

5.3.3 Operational Feasibility

4. 3. 1 Technical Feasibility

The Technical Feasibility Study assesses the details of how you will deliver

a product or service (i.e., materials, labor, transportation, where your business will

be located, technology needed, etc.). Think of the technical feasibility study as the

logistical or tactical plan of how your business will produce, store, deliver, and

track its products or services.

A technical feasibility study is an excellent tool for trouble-shooting and long-term

planning. In some regards it serves as a flow chart of how your products and

services evolve and move through your business to physically reach your market.

4. 3. 2 Economic Feasibility

Feasibility studies are crucial during the early development of any project and form

a vital component in the business development process. Accounting and Advisory

feasibility studies enable organizations to assess the viability, cost and benefits of

projects before financial resources are allocated. They also provide independent

project assessment and enhance project credibility.

Built on the information provided in the feasibility study, a business case is used to

convince the audience that a particular project should be implemented. It is often a

prerequisite for any funding approval. The business case will detail the reasons

why a particular project should be prioritized higher than others. It will also sum

up the strengths, weaknesses and validity of assumptions as well as assessing the

financial and non-financial costs and benefits underlying preferred options.

4. 3. 3 Operational Feasibility

Operational Feasibility: Under this category of service we conduct a study

to analysis and determine whether your business need can be fulfilled by

using a proposed solution. The result of our operational feasibility Study will

clearly outline that the solution proposed for your business is operationally

workable and conveniently solves your problems under consideration after

the proposal is implemented. This is sometimes referred to as ‘Feasibility

Evaluations’. We would precisely describe how the system will interact with

the systems and persons around. Our feasibility report would provide results

of interest to all stakeholders

Module Description

Command Authentication

Compared with a client, because attack in the proposed system do not receive commands

from predefined places, it is especially important to implement a strong command authentication.

A standard Automatic authentication would be sufficient. A master generates a pair of Log file

for monitoring Ddos Attack. There is no need for key distribution because the public automatic

is hard-coded in key generation program. Later, the command messages sent from the master

could be digitally signed by the private key to ensure their authentication and integrity

automatically. This Auto-based authentication could also be readily deployed by current Server .

So DDos hacking is not a major issue.

Individualized Log File

In the proposed, the server randomly generates its symmetric e Log key. With the help of

same key only the client will be able to decrypt the contents.

This individualized log file is guarantees that if defenders capture each and every attack

on real time transaction, they wont be able to restrict attack until and unless the hacker knows

the detection and prevention. Thus the individualized will not let the systems to be

compromised.

Networks

A Server network is a general method of transforming any function (usually called an

Ffunction) into a permutation. It was invented by Horst Server and has been used in many block

cipher designs. The working of a Festal Network is given below:

Split each block into halves

Right half becomes new left half

New right half is the final result when the left half is XOR’d with the result of applying f

to the right half and the key.

Note that previous rounds can be derived even if the function f is not invertible.

6.SYSTEM DESIGN

6.1 DATABASE DESIGN

TABLE 6.1.1 User Details

S. No FIELD DATA

TYPE

SIZE

1 User_Name String 25

2 Password String 25

3 User_Type String 15

4 Date Date/Time 6

6.2 DATA FLOW DIAGRAM

Level 0

Level 1

Master Sending file Command & Control Server(C&C)

Easily affected by hackers

Master Taken Control Over all peer to peer

Implementing

Hybrid Peer-To-Peer

Botnet

Harder To Be Shut Down, Monitored, And Hacked

Master Monitoring

Monitoring the unauthorized system

Monitoring compromised system

Implementing

Hybrid Peer-To-Peer

Botnet

Harder To Be Shut Down, Monitored, And Hijacked By BOTNET

7. SOFTWARE TESTING

7.1 TESTING

INTRODUCTION:

After finishing the development of any computer based application, the next

complicated time consuming process is testing. During the time of testing only the

development company knows that, how far the user requirements have been met.

The testing methods applied to our project are as follows.

7. 1 Unit Testing

7. 2 Integration Testing

7. 3 Validation Testing

7. 4 Output Testing

7. 5 Acceptance Testing

7.2 TESTING METHODOLOGY

7.2.1 UNIT TESTING:

In unit testing each module is tested individually. It focuses the verification efforts

on the smallest unit of software in the module. This is known as module testing.

In the project all the modules are tested separately. For our project testing

is performed at programming stage itself. In this testing each module project is

found to work satisfactorily with regard to the expected output from the module.

There are some validations for fields. The unit testing is performed now and then

whenever a patch is delivered for each module. This makes our project standard.

Unit testing comprises the set of tests performed by an individual programmer

Prior to integration of the unit in to larger system. A program unit is

usually small enough that the programmer who developed it can test it in a great

detail. In unit testing the modules are independent of one another are tested, the

test data for unit testing should follow each condition and option this testing helps

to find out the errors in coding and option.

7.2.2 INTEGRATION TESTING:

Integration testing is the phase of software testing in which individual

software modules are combined and tested as a group. In this project the parts of a

module are tested first and then it will test some of its parts, integration testing is

done successfully.

7.2.3 VALIDATION TESTING:

It begins after the integration testing is successfully assembled. Validation

succeeds when the software functions in a manner that can be reasonably accepted

by the client. In this project, the majority of the validation is done during the data

entry operation where there is a maximum possibility of entering wrong data.

Other validation will be performed in all process where correct details and data

should be entered to get the required results.

7.2.4 OUTPUT TESTING:

After performing the validation testing, the next step is output testing of the

proposed system since no application would be termed as useful until it produces

the required output in the specified format.

7.2.5 ACCEPTANCE TESTING:

User Acceptance Testing is the key factor for the success of any application.

The project under consideration is tested for user acceptance by constantly keeping

in touch with perspective system users at the time of developing and making

changes whenever required.

All the above mentioned testing techniques are successfully completed by

our project.

8. CONCLUSION

Both Flash crowds and DDOS (Distributed Denial -of-Service) attacks have very similar

properties in terms of internet traffic, however Flash crowds are legitimate flows and

DDOS attacks are illegitimate flows, and DDOS attacks have been a serious threat to

internet security and stability. In this paper we propose a set of novel methods using

probability metrics to distinguish DDOS attacks from Flash crowds effectively, and our

simulations show that the proposed methods work well. In particular, these methods

can not only distinguish DDOS attacks from Flash crowds clearly, but also can

distinguish the anomaly flow being DDOS attacks flow or being Flash crowd flow from

Normal network flow effectively. Furthermore, we show our proposed hybrid probability

metrics can greatly reduce both false positive and false negative rates in detection. In this

paper we surveyed on four different techniques to differentiate DDOS attack from flash

crowd. Among the techniques “Discriminating DDOS Attacks from Flash Crowd Using

Flow Correlation Coefficient” shows better results.

APPENDIX

a) Screen Layout

Login Form

Screen Shot

1. BIBLIOGRAPHY