226 Broker Interactions for Intra- and Inter-enterprise
Transport support for applications
WebSphere Business Integration Message Broker provides the following
transports mechanisms to allow clients to communicate with applications through
message flows:
? WebSphere MQ Web Services Transport allows Web services clients using
XML messages and the HTTP protocol running over TCP/IP to communicate
with applications through message flows in a broker.
? WebSphere MQ Real-time Transport is a lightweight protocol optimized for
use with non-persistent messaging. JMS applications communicate with the
broker using TCP/IP ports.
? WebSphere MQ Telemetry Transport is a lightweight publish/subscribe
protocol flowing over TCP/IP. This protocol is used by specialized applications
on small footprint devices that require a low bandwidth communication,
typically for remote data acquisition and process control.
? WebSphere MQ Multicast Transport is used by dedicated multicast-enabled
JMS application clients to connect to brokers. Applications communicate with
the broker by writing data directly to TCP/IP ports. This protocol is optimized
for high volume, one-to-many publish/subscribe topologies.
? WebSphere MQ Enterprise Transport supports WebSphere MQ applications
that connect to WebSphere Business Integration Message Broker by writing
data to and reading data from message queues.
? WebSphere MQ Mobile Transport is used exclusively by WebSphere MQ
Everyplace clients. WebSphere MQ Everyplace is an application designed
primarily for messaging to, from, and between pervasive devices. These are
typically small, handheld devices, such as mobile phones and PDAs. A bridge
queue on the broker's queue manager provides an interface for the
WebSphere MQ Everyplace clients to the broker services.
9.3 Applying patterns
The Retail system needs to get delivery dates based on a part or system number
from the appropriate Wholesale supplier. Each Wholesale supplier has its own
unique implementation that returns the delivery date to requesters but has
basically the same input and output formats for incoming requests and outgoing
responses. Each Wholesale system does not necessarily support the same
protocol for transmission of the requests and responses.
The Retail system knows the part number it wants a delivery date for, but doesn’t
know which Wholesale suppliers can deliver the part. In the event that there are
multiple Wholesale suppliers for the part, the Retail system wants to know the
earliest possible delivery date.
Chapter 9. Broker solutions using WebSphere Business Integration Message Broker 227
From this, ITSO Electronics determined the following requirements:
? Each Wholesale department must expose its services as Web services.
The actual implementation on the Wholesale systems must be transparent to
the Retail system. The request for a delivery date will be done as a Web
service invocation, relieving the Retail system from having to know how the
request is fulfilled.
? The design must be able to support multiple protocols and perform protocol
transformation.
? The design must be able to decompose the incoming request into multiple
Web service requests, then must be able to recompose the responses into a
reply. For this, a broker will be used.
? The broker must be able to inspect the incoming request and determine which
Wholesale system it needs responses from in order to create a complete
reply for the Retail system. It must be able to send simultaneous requests to
the Wholesale systems, and manipulate the responses so the earliest
delivery date returned (and not all delivery dates) can be sent as a response.
9.3.1 Application patterns
ITSO Electronics will address the solution in three stages:
? In the first stage, they will integrate the internal Retail and Wholesale
systems, allowing the Retail systems to get a delivery date based on a part
number.
? In the second stage, they will implement a solution that allows the Retail
systems to publish sales information to internal Wholesale systems.
? In the third stage, they will extend the solution from stage 1 to integrate the
internal Retail systems with external wholesale partners. This will allow the
Retail systems to get delivery dates for parts supplied by external Wholesale
suppliers.
Stage 1: Internal delivery date
In stage 1, the solution will address the internal Retail and Wholesale systems.
The use of a broker provides the ability to:
? Perform any protocol transformation required between the Retail and
Wholesale systems.
? Perform intelligent routing of incoming messages, relieving the Retail systems
from knowing which Wholesale systems can supply the part.
? Route the request from the Retail system to multiple Wholesale systems
simultaneously. In the event that multiple Wholesale systems can supply the
228 Broker Interactions for Intra- and Inter-enterprise
part, the incoming message can be decomposed into multiple requests. The
responses from the Wholesale suppliers can be recomposed into a single
response which can then be manipulated to return only the earliest delivery
date to the Retail system.
Because the applications to be integrated are all internal to ITSO Electronics,
they decided to use the Application Integration::Broker application pattern to
design the solution.
The design implemented in this stage by ITSO Electronics is shown in Figure 9-2
and Figure 9-3.
Figure 9-2 Basic Broker implementation
Stage 2: Publish sales forecast
Figure 9-3 Extended enterprise implementation
Stage 3: Extended enterprise
In this stage, ITSO Electronics will enhance the solution so that ITSO Electronics
Retail systems can request delivery dates from external Wholesale companies.
Because external partners will be targeted, the Extended Enterprise::Exposed
Broker application pattern is selected for the solution. A gateway will be used to
make the external processes available to the internal Retail system process.
SOAP/
HTTP
Broker
SOAP/
HTTP
ITSO Electronics
Wholesale
ITSO Electronics
Wholesale
ITSO
Electronics
Retail
SOAP/
HTTP
ITSO
Electronics
Retail
JMS/IP
ITSO
Electronics
Wholesale
Broker
JMS/IP
ITSO
Electronics
Wholesale
Chapter 9. Broker solutions using WebSphere Business Integration Message Broker 229
The design implemented in this stage by ITSO Electronics is shown in
Figure 9-4.
Figure 9-4 Extended enterprise implementation
9.3.2 Product mappings
The product mappings for the three stages are all based on WebSphere
Business Integration Message Broker as the broker. In the Extended Enterprise
mapping, the broker will access external Web services through the Web Services
Gateway.
Application Integration
In stage 1, the need for a broker has been identified. The WebSphere Business
Integration Message Broker will be used to provide the broker functionality in this
solution (Figure 9-5).
ITSO
Electronics
Retail
SOAP/
JMS
SOAP/
HTTP
Firewall
Firewall
Firewall
Firewall
DMZ
External
Wholesale
External
Wholesale
Broker
SOAP/
HTTP
Gateway
230 Broker Interactions for Intra- and Inter-enterprise
Figure 9-5 Product mapping for Application Integration::Broker
The source application is the Retail system. The target applications are the
Wholesale inventory systems.
Extended Enterprise
In the previous product mapping, the Broker node is an internal asset with
access to internal resources. In order to gain access to external resources
communication has to pass through the servers in the DMZ and the corporate
firewall.
The Web Services Gateway is a run-time component that can be used to provide
access to external Web services by representing them as internal Web services.
The mapping between the external resource and the internal representation is
done based on WSDL files. It can also perform the reverse service by making
internal Web services available externally.
In this product mapping, the message flows within the Message Broker will
access external Web services using the Web Services Gateway.
Figure 9-6 shows the product mapping for the Exposed Broker.
WebSphere
Application Server
V5.0.2.1
Broker
Application
Server/
Services
Application
Server/
Services
Application
Server/
Services
Application
Server/
Services
WebSphere Business Integration
Message Broker V5 + CSD2
SOAP/
HTTP
SOAP/
HTTP
Source
Application
Broker
Rules
Target
Application
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