Patterns: Implementing Self-Service in an SOA Environment

Chapter 4. Runtime patterns 63

The Runtime pattern for the Router application pattern has been broken down

into a generic Runtime pattern and then further refined using an SOA profile.

4.3.1 Generic Runtime pattern for Router

The Runtime pattern shown in Figure 4-4 represents one solution for the Router

application pattern.

Figure 4-4 Router application pattern::Generic runtime pattern

This Runtime pattern uses a Web server redirector node in the DMZ to serve

static HTML pages to the client. Requests for dynamic data are forwarded to the

application server in the internal network. Together, these two nodes provide the

presentation tier, capable of handling multiple, diverse, presentation styles.

Using a redirector allows you to place the bulk of the business logic behind the

protection of both the protocol and domain firewalls.

In addition to presentation logic, primarily in the form of JavaServer Pages

(JSPs), the application server contains some business logic. This is primarily in

the form of the controlling servlets required to access the back-end applications.

The application server builds a request based on user input and passes it to the

integration server.

The integration server examines the request, determines the appropriate

destination, and forwards it to the chosen back-end application, where the

Internal Network

Demilitarized Zone

(DMZ)

Outside World

Protocol

Firewall

I

N

T

E

R

N

E

T

Public Key

Infrastructure

User

Web

Server

Redirector

Domain Name

Server

Directory and

Security

Services

Application

Server

Integration

Server

Existing

Applications

and Data

Domain

Firewall

Presentation

Router application pattern

Application

Application

Router

Presentation