Chapter 3. Scenario overview and design 71
Security involving authentication and authorization is paramount. Encryption of
the data transmitted during order requests is highly desirable. The use of single
sign-on mechanism using a directory service is requested.
3.2 Logical design
We decided to use a series of business processes in a component design with
layered services for the business workflow, the system processes, and the EIS
components. The critical business processes represent a set of grouped services
to form a logical unit of work. The system processes provide a virtual or logical
enterprise service bus feature where routing, domain data transformation, and
context based execution can occur.
Figure 3-5 shows the logical design of our services and the EIS systems they
use for their processes.
Figure 3-5 Logical high-level services view
The Web Site Portal interacts with the firm’s Trading Services, which use other
business services to complete the request. The Broker Service provides the
option to buy or sell shares and uses the Broker EIS. The Trader Service
provides access to the Trader Application EIS, which contains data that is related
to trading stocks. The Stock Analysis Service retrieves the stock information that
is required from the Stock Quote EIS.
User
Trading Firm - High-Level View
Stock Quote
EIS
Trading
Services
Trader
Service
Stock
Analysis
Service
Broker Service
Broker
EIS
TraderApp
EIS
Web Site Portal EIS Systems
72 Managing Information Access to an EIS Using J2EE and Services Oriented Architecture
3.2.1 High-level design views
This section describes the logical high-level system view showing the
components and enterprise applications involved. It gives a high-level view of the
processes that make up the business functionality of the system and then looks
at the services that are provided in the system.
System view
We decided to go with a component design with layered services for the business
workflow, the system processes, and the EIS components. Figure 3-6 shows the
logical design of our components and how they interact with each other. There is
a system process that provides for context-based requests and an facade into
the EIS components.
Figure 3-6 Logical high-level system components view
The Critical Business Process is where the business-centric activities occur. The
Internet Trading process is the main process in the system. It coordinates the
activities for the buy shares scenario. The Stock Broker process handles the task
of sending a request to purchase the shares and any other business needs
Logical High-Level View
Stock
Broker
CBP
EIS
System
Process
SP
EIS
Component
IMS
Async
Trade
IMS
Internet
Trading
CBP
EIS
System
Process
SP
EIS
Component
CICS
Trader
App
CICS
Stock
Analysis
CBP
EIS
System
Process
SP
EIS
Component
Database
Stock
Quote
Repository
CBP - Critical Business Process
SP - System Process
Chapter 3. Scenario overview and design 73
required during the request. The Stock Analysis process validates and retrieves
the stock information and decides which provider it will use.
The EIS System Process uses context information found in the request to use
the appropriate EIS component, including information such as the version of the
back-end system that it should use.
The EIS Component provides connectivity to the EIS system or repository.
Figure 3-7 shows the logical components and interaction mechanisms in the
system.
Figure 3-7 Logical high-level interaction view
In the system, the major logical components are presentation, business
processes, and services as well as the EIS connectivity services which are the
back-end data sources.
The presentation layer could be developed using Struts, JSP, or JavaServer
Faces. The business process and services layer are Business Process
Execution Language for Web Services (BPEL) processes that are integrated with
the appropriate bindings for the service calls. The EIS connectivity services
logical component includes J2C resource adapters and WebSphere Business
Logical High-Level View
Stock
Broker
BPEL
EIS
System
Process
BPEL
EIS
Component
Session Bean
JMS
Trade
IMS
Internet
Trading
BPEL
EIS
System
Process
BPEL
EIS
Component
Session Bean
Trader
App
CICS
Stock
Analysis
BPEL
EIS
System
Process
BPEL
EIS
Component
Stock
Quote
Repository
EJB
EJB
SOAP
WSI-F
J2C
Resource
Adapter
J2C
Resource
Adapter
WBI
Adapter

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