ACS 3907 E-Commerce•The Web server is physically separated from the application server. •This is...

©Bowen Hui, Beyond the Cube Consulting Services Ltd.

© 2014 Pearson Education, Inc. Publishing as Prentice Hall 1

ACS 3907E-Commerce

Lecture 5-1

Instructor: Kerry Augustine



• Client/server architecture

• Two-tier vs. three-tier architecture

• Four-tier architecture

• Web server software/ Site management tools

• E-Commerce merchant server platform

• Hardware platform

• E-Commerce site tools/ Personalization tools

• Mobile Commerce (M-Commerce) architecture

• Cloud Computing

E-Commerce Design Architecture – Part 1



Client/Server Architecture

• Model of computing where roles and responsibilities are distributed between servers and clients

Two-Tier Architecture(1) Client (2) Server + Database

Three-Tier Architecture

(1) Client

(2) Server

(3) Database



Client/ Server Architecture

• Front-end (client) systems are those processes with which a user interfaces, and over which a customer can exert some control.

• For an eBusiness, front-end systems are the Web site processes that customers use to view information and purchase products and services.



• Back-end (server) systems are those processes that are not directly accessed by customers.

• Back-end systems include the business’s TPS and MIS systems that handle the accounting and budgeting, manufacturing, marketing, inventory management, distribution, order-tracking, and customer support processes.

Client/ Server Architecture



Client/Server Architecture (cont.)

• Strictly speaking, clients and servers refer to software

• Client’s tasks:– Sends requests to servers

– Display results from server to user

• Server’s responsibilities:– Satisfies requests

– May “consult” other sources

– May fail to satisfy requests

• Servers cannot initiate dialog with clients

• May exist on same physical machine or separate machines



Client/Server Architecture (cont.)

• Servers may respond to multiple clients

• Clients may send requests to multiple servers

• Examples of servers:– Mail server – manages email

– Database server – stores info on customers, products, prices

– Web server – delivers HTML content to clients

– Ad server – maintains web-enabled DB of ad banners, allowing customized/personalized display of ads based on customer behaviourand characteristics

• User application components: presentation, processing, data

• How to divide up components in architecture?



Advantages of Client/Server Architecture

• Scalability – Increase/decrease computing capacity easily by adding more clients or

servers

• Interoperability – Clients, servers, database can be run on different operating systems

• Reliability – Failure of one component in network most likely does not shut down

whole system

• More elaborate GUIs – Can dedicate clients’ computing resources solely for GUI management



Disadvantages of Client/Server Architecture

• Complexity – Many machines must work together to communicate and coordinate;

Systems must be designed carefully

• Need for specialized training– Development and support staff require specialized knowledge and

experience

• Network management tools less robust– These tools are still “new” relative to other technologies



Considerations for Choosing Architecture Design

• System-related:– Complexity of the application

– Level of integration required

• Process-related:– Development time required

– Flexibility and maintenance of system

• Client/Users-related:– Number of users

– User’s geographical dispersion

– Nature of networks and transaction needs of the application

– Response times



• Most common implementation: – Client: presentation, processing

– Server: processing, data

• Client responsible for functionality and business logic

• Server handles data-intensive tasks via database engine (integrity checks, querying)

• Most common language of communication: SQL

– Requires “tight” linkage between server and client

Two-Tier Architecture




• Clients are responsible for presentation only

• Middle-tier servers:– Handle data processing

– Act as clients and send requests to other servers

• Back-end server dedicated to data

• Communication via remote procedure calls (RPC)– Can be accomplished in Java, C, etc.

– Client requests specify parameters and return data structures, and do not need to “speak” the server’s language




RPC RPC



Advantages

2-Tier 3-Tier

Fast application development; low initial development efforts required

Development expertise can be more focused to specific tiers

2-tier tools are extremely robust Separation allow parallel development

Good for iterative prototyping and rapid application development techniques

Data and process changes do not affect clients

Middle-tier servers help decrease and localize network traffic

Reduce data needs (memory, processing, disk storage) for clients

Modularity, leading to higher code reuse, lower maintenance and migration costs when switching client applications

Lower subsequent development efforts



Disadvantages2-Tier 3-Tier

Not suited for dispersed, heterogeneousenvironments (e.g. cross-departments, cross-platforms)

3-tier tools/platforms are more complex;require more planning

Not suited for environments with rapidly changing business rules

More complicated code, thus, increases chance of system failure

Difficulties with version control and re-distribution of client application

Requires network traffic management, server load balancing, fault tolerance

Proliferation of end-user query tools can compromise database server security (could amend via middleware)

High initial development effort needed

Client tools and SQL middleware are proprietary

Higher subsequent development efforts

High migration costs for client tools



Four-Tier Architecture

• The Web server is physically separated from the application server. • This is often done for security reasons, where the Web server is deployed into a

perimeter network and accesses the application server located on a different subnet. • In this scenario, you might implement a firewall between the client and the Web tier,

and another firewall between the Web tier and the application or business logic tier.

• Consider the 4-tier pattern if security requirements dictate that business logic cannot be deployed to the perimeter network, or you have application code that makes heavy use of resources on the server and you want to offload that functionality to another server.



Example - Four-Tier Architecture

• Internet Website: This application is used with popular and recent browsers on desktop and mobile devices and is structured in 4 layers: client (browser), UI (Web), Application logic (Services) and Database.

• Intranet Application: this application is used on the current corporate browser (Internet Explorer 8) and is also structured in 4 layers.

• Desktop Application: this application is deployed directly to the desktop using Click Once and connects to a service layer for application logic and then a database layer. These will be internal applications only.

Client Tier Web Tier ApplicationTier

DatabaseTier

ApplicationTier

Web Tier Client TierDatabaseTier



Web Server Software

• Apache

– Leading Web server software (60% of market)

– Works with UNIX, Linux operating systems

• Microsoft’s Internet Information Server (IIS)

– Second major Web server software (20% of market)

– Windows-based



• Table 4.4, Page 208



Site Management Tools

• Basic tools

– Included in all Web servers• Verify that links on pages are still valid

• Identify orphan files

• Third-party software for advanced management

– Monitor customer purchases, marketing campaign effectiveness, and so on



Web Site Management Services

34

• 24/7 server monitoring & rescue

• Response to alerts

• Security monitoring

• Initial system tuning & hardening

• Regular server updates

• 911 patching

• Backup monitoring & audits

• Security audits & hardening

• 24/7 on-demand support

• Infrastructure design & setup

• Website maintenance

• Small website fixes

• Server/App migrations

• Mail error fixes

• Performance tuning

• Hardware fault resolution

• Website monitoring & rescue



Application Servers

• Web application servers:

– Provide specific business functionality required for a Web site

– Type of middleware• Isolate business applications from Web servers and databases

– Single-function applications being replaced by integrated software tools that combine all functionality needed for e-commerce site



E-commerce Merchant Server Software

• Provides basic functionality for sales

– Online catalog• List of products available on Web site

– Shopping cart• Allows shoppers to set aside, review, edit selections, and then

make purchase

– Credit card processing• Typically works in conjunction with shopping cart

• Verifies card and puts through credit to company’s account at checkout



Merchant Server Software Packages

• Integrated environment that includes most of functionality needed

• Key factors in selecting a package– Functionality

– Support for different business models

– Business process modeling tools

– Visual site management and reporting

– Performance and scalability

– Connectivity to existing business systems

– Compliance with standards

– Global and multicultural capability

– Local sales tax and shipping rules



Merchant Server Software Packages

https://www.youtube.com/watch?time_continue=9&v=P5SKWA6_F7k&feature=emb_logo



Web Services and Open-Source Options

• Options for small firms

– Hosted e-commerce sites• Offer site building tools and templates

• Example: Yahoo’s Merchant Solutions

– Open-source merchant server software• Enables you to build truly custom sites

• Requires programmer with expertise, time



Hosted Web Services

https://www.youtube.com/watch?v=Ai9Csq3RurQ



Hosted Web Services

https://magento.wistia.com/medias/nsxe6vqzs6



The Hardware Platform

• Hardware platform:

– Underlying computing equipment needed for e-commerce functionality

• Objective:

– Enough platform capacity to meet peak demand without wasting money

• Important to understand the factors that affect speed, capacity, and scalability of a site



Right-Sizing Your Hardware Platform: The Demand Side

• Customer demand: – Most important factor affecting speed of site

• Factors in overall demand:– Number of simultaneous users in peak periods

– Nature of customer requests (user profile)

– Type of content (dynamic vs. static Web pages)

– Required security

– Number of items in inventory

– Number of page requests

– Speed of legacy applications



Right-Sizing Your Hardware Platform:The Supply Side

• Scalability:

– Ability of site to increase in size as demand warrants

• Ways to scale hardware:

– Vertically• Increase processing power of individual components

– Horizontally• Employ multiple computers to share workload

– Improve processing architecture



Factors in Web Site Optimization

Figure 4.10, Page 205



Mobile Commerce (M-Commerce)

• Takes traditional EC models onto wireless platform

• Fastest growing platform for EC models

• Wireless technologies:– 3G = Third-generation wireless

– 4G = Fourth-generation wireless (LTE)

– LTE = Long-term Evolution

– 5G = Fifth-generation wireless



Mobile Commerce (M-Commerce)



Cellular System: 5G

• 5G is the latest generation of cellular mobile communications. It succeeds the 4G (LTE/WiMax), 3G (UMTS) and 2G (GSM) systems. 5G performance targets high data rate, reduced latency, energy saving, cost reduction, higher system capacity, and massive device connectivity.

• The first phase of 5G specifications (Release-15) was completed in April 2019 to accommodate the early commercial deployment.

• The second phase in Release-16 is due to be completed by April 2020 for submission to the International Telecommunication Union (ITU) as a candidate of IMT-2020 technology. [Source]

https://en.wikipedia.org/wiki/5G



Cellular System: 5G



Cloud Computing

• Software and storage provided as an internet service and accessed within a web browser

• Example: Email, Data storage, skydrive, tax software, flicker, facebook.

• Radically reduces costs of:Building and operating Web sitesInfrastructure, IT supportHardware, software



Cloud Computing – Advantages to Businesses

• Outsourcing Resources – Saves on system design, installation, and maintenance

• Provides an ability to access corporate systems from any Internet-connected device

• Increases the data storage capabilities of the firm

• Data safeguarding responsibility of service provider



Google Cloud Centre

https://www.youtube.com/watch?v=XZmGGAbHqa0&t=121s



https://www.youtube.com/watch?v=PBx7rgqeGG8

ACS 3907 E-Commerce•The Web server is physically separated from the application server. •This is...

Documents

Transcript of ACS 3907 E-Commerce•The Web server is physically separated from the application server. •This is...