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Example Scenarios

which they have already implemented the business logic. For that reason, and

since the primary interest of most readers is on Web services, this chapter keeps its

focus on Web service development and does not delve into the details of designing

and implementing business logic.

3.1

Example Scenarios

Let's revisit the scenarios introduced in  Typical Web Service Scenarios  on

page 11 the adventure builder enterprise scenario and the examples illustrating

when Web services work well for an enterprise from the point of view of design 

ing a Web service. This chapter, rather than discussing design issues abstractly,

expands these typical scenarios to illustrate important design issues and to keep the

discussion in proper perspective. 

In this chapter, we focus on three types of Web services:

1. An informational Web service serving data that is more often read than updat 

ed clients read the information much more than they might update it. In our ad 

venture builder example, a good scenario is a Web service that provides 

interested clients with travel related information, such as weather forecasts, for 

a given city. 

2. A Web service that concurrently completes client requests while dealing with

a high proportion of shared data that is updated frequently and hence requires

heavy use of EIS or database transactions. The airline reservation system part 

ner to adventure builder is a good example of this type of Web service. Many

clients can simultaneously send details of desired airline reservations, and the

Web service concurrently handles and conducts these reservations.

3. A business process Web service whose processing of a client request includes 

starting a series of long running business and workflow processes. Adventure 

builder enterprise's decision to build a service interface to partner travel agen 

cies is a good example of this type of Web service. Through this service inter 

face, partner agencies can offer their customers the same services offered in 

adventure builder's Web site. The partner agencies use adventure builder's 

business logic to fulfill their customer orders. A service such as this receives 

the details of a travel plan request from a partner agency, and then the service 

initiates a series of processes to reserve airlines, hotels, rental cars, and so forth 

for the specified dates.