Running head: ARCHITECTURE DESIGN 1

Architecture Design

Neil Cameron

Rasmussen College

Author note:

This architecture design analysis is being submitted on November 9th, 2014 for Professor

Robert Haluska’s Section 2 Systems Analysis Fall 2014 Class

ARCHITECTURE DESIGN 2

Architecture Design

In the word of the System Development Life Cycle (SDLC) during the design phase the project manager comes to the decisions of the architecture.

As of today almost every business runs on client-server architecture however with new technologies like virtualization and cloud computing more and more businesses will be adapting this that architecture as it becomes the norm.

Within the client-server architecture are key concepts to how they systems run. The first thing is to understand what the client-server architecture is. The client is the user’s PC or device that is connected to the network. In a client-server system the client is (PC) is responsible for the running the presentation logic. In other words the user has a user interface app that interacts with the data stored in a server. The server is where all the data that the user will enter or retrieve is housed. This is what a client-server system looks like:

As we move on it should be noted that when the user runs all or most of the application logic it is also referred to as a thick-client. The complete opposite called a thin-client is when the client only supports a small portion of the application logic.

There are different architecture ways in which a client-server system can be partitioned. In the above diagram because it is one client and one server it is referred to as a two –tiered architecture. Yes there can me more than two-tiered architectures. The next would be a three-tiered architecture as follows:

If the middle-tier itself is partitioned into more components this would be considered an n-tiered architecture and would look as follows:

ARCHITECTURE DESIGN 3

As an example of a real system that runs in both three-tiered and n-tiered is the Oracle9iAS Discoverer. This is a business intelligence tool used for analyzing data. In a nutshell users (clients) access and analyze the data stored in a database (server). The system runs on two types of architecture. When it runs on a three-tiered architecture it is referred to as Discoverer Plus. With the n-tier architecture it is referred to as the Discoverer Viewer.

The main difference is where the load balance is distributed. Here is the three-tiered architecture of the Discoverer Plus:

- First Tier – Client - Any users with Java-enabled browser - Middle Tier – The Discoverer Services

o HTTP Server – Contains Discoverer applet files, HTML files, Locatoro The Application Servers – Contain the session and preferences

- Third-Tier – The Database

This is the Discoverer Plus three-tiered architecture diagramed out:

With the Discoverer Viewer n-tiered architecture the load is balanced different as follows

- First Tier - Client – Any computer with a Web Browser installed - Second Tier – The HTTP Server

o Contains the Java-enabled servlet engine (NO JAVA IS ON THE CLIENTS), Discoverer 3i Viewer Servlet, and Locator

- Third Tier – The Discoverer Serviceso The Application Servers – Contain the session and preferences

- Forth Tier – The Database

ARCHITECTURE DESIGN 4

This is the Discoverer Viewer n-architecture diagramed out:

As you can see in the n-tier architecture the Java portion is moved from the client in the three-tiered and placed into the HTTP server to make it an n-tier.

ARCHITECTURE DESIGN 5

When it comes to the flow data this is how the Discoverer Plus three-tiered architecture works

1. The user launches a Web browser on a client computer and types the URL of the HTTP Server.

2. The Web browser accesses the URL on the HTTP Server. 3. The HTTP Server retrieves the HTML pages and the Discoverer applet and transmits

them to the client computer. 4. The Discoverer applet finds the Locator (the recommended location for the Locator is on

the HTTP Server). 5. The Locator starts a Session component on an Application Server machine and a

Discoverer session starts. 6. The Session component creates a reference and passes the reference to the Locator. 7. The Locator passes the reference to the client computer. 8. The client computer uses the reference to contact the Discoverer session directly. The

HTTP server is no longer being accessed. 9. The Discoverer session requests and receives data from the database. 10. The Discoverer session transmits data to the Web browser on the client machine

ARCHITECTURE DESIGN 6

This is how the data flows in the Discoverer Viewer n-tiered architecture works.

1. The user launches a Web browser on a client computer and types the URL of the HTTP Server.

2. The Web browser accesses the URL on the HTTP Server. 3. The Discoverer Viewer Servlet interprets the HTTP request. 4. The Locator starts a Session component on an Application Server machine and a

Discoverer session starts. 5. The Discoverer session requests and receives data from the database. 6. The Discoverer session transmits data to the Discoverer Viewer Servlet. 7. The Discoverer Viewer Servlet generates an HTML page and sends it to the browser.

As you can see the n-tiered Discoverer Viewer flow of data is more efficient with fewer steps involved in the flow of data.

ARCHITECTURE DESIGN 7

References

Dennis, A., Wixom, B. H., & Roth, R. M. (2012). Systems analysis & design (5th ed.). John

Wiley & Sons, Inc.

Oracle9iAS Discoverer Plus and Viewer Configuration Guide Release 4.1 for UNIX A90288-01.

(n.d.). Retrieved November 7, 2014, from Oracle website:

https://docs.oracle.com/cd/A97335_02/busint.102/a90288/overview.htm