Oracle Application Server 10g Essentials [Electronic resources] نسخه متنی

15.1 Oracle Application Server InterConnect

You can use OracleAS InterConnect to integrate
applications from Oracle, other software providers, or custom-built
applications using message-oriented middleware. OracleAS InterConnect
enables integration through modeling rather than relying on extensive
programming techniques. Integration logic is separate from the
integration platform. OracleAS InterConnect components include a hub,
adapters, and a Development Kit. Figure 15-1 shows a
typical deployment configuration.

Figure 15-1. Typical OracleAS InterConnect deployment

The OracleAS InterConnect design and modeling tool, called
iStudio,
features easy-to-use wizards. Intended for use by business analysts,
iStudio largely eliminates the need to write
code when creating business rules and transformation integration
logic. Users of iStudio can define and map data
to be exchanged between applications, and can configure and deploy
the integration. Objects can be locked within the tool, thus enabling
multiple users to model and design simultaneously. OracleAS
InterConnect supports metadata versioning so that multiple versions
of the same object can coexist or be active at the same time. If
business process collaboration is desired, Oracle Workflow can define
the business processes. The iStudio tool is then
used to associate semantic maps with these business processes.

Components connected with OracleAS InterConnect and created in
iStudio are called application
views
. Application
views include interest in specific
messages, internal datatype identification, and information on how a
message should be mapped to or from an internal datatype. A
common view

is a hub view in which each spoke is an application view
participating in the integration. Figure 15-2 shows
the hub-and-spoke nature of
OracleAS InterConnect deployment between the common view and
application views.

Figure 15-2. Typical OracleAS InterConnect hub and spoke

Common views can contain the following components:

Business objects

A collection of logically related
integration pointslogical occurrences that trigger
communications between applications

Event

An integration point used to model
"publish and subscribe"

Procedure

An integration
point used to model "request/reply"

Common datatype

Data
definition for reuse

Transformations, sometimes call
mappings

, are the integration points to
application views.

Generated models and designs are stored in the
OracleAS InterConnect metadata
repository, which is part of a hub. At runtime, the metadata
repository is the source of instructions enabling message exchange to
occur. Runtime management, which is handled through Oracle
Enterprise Manager, includes such
management tasks as:

Starting and stopping components

Monitoring message flow

Performing problem detection

Handling error management

15.1.1 OracleAS InterConnect Adapters and Messages

OracleAS
InterConnect Adapters provide
connectivity via a bridge, the protocol/application-specific portion
of the adapter. The adapters transform and route messages between an
application and the hub. Data is transformed from application views
to common views and from common views to application views, as
defined in the metadata repository. Figure 15-3
shows the architecture of an adapter.

Figure 15-3. OracleAS InterConnect Adapter architecture

A number of prepackaged OracleAS InterConnect adapters are available,
including:

Technology Adapters

These adapters are used in cases where
endpoints don't have APIs. They include Oracle
database, Oracle AQ, MQSeries, HTTP/S, SMTP, FTP, and CICS.

Packaged Application Adapters

These
adapters are used to integrate JD
Edwards, PeopleSoft, SAP, and Siebel applications.

Adapter SDK

The SDK enables the creation of adapters for
applications and protocols that aren't supported by
other adapters. The kit is a collection of Java JAR and Javadoc
files.

Messages
are commonly communicated using database adapters, Oracle AQ, or XML
messaging, or through the
Data Definition Description Language
(D3L). All OracleAS InterConnect messages are guaranteed to be
delivered exactly once in the order sent. Messages can be
load-balanced across multiple adapters using
Real
Application Clusters (RAC), a clustered Oracle database
configuration. Routing of messages can be implemented using business
rules based on message content.

Interfaces to Oracle's E-Business Suite of Applications are typically via database access to the Oracle Applications interface tables or through an XML gateway (as XML is supported in several of the technology adapters). Interfaces can be created to Oracle's CRM application via SOAP and to Oracle's Supply Chain applications via the Supply Chain Trading Connector (SCTC).

OracleAS InterConnect supports two
distinct models:

Publish and subscribe

With this model, applications may be subscribers. These subscribers
receive messages whenever they are published by specific
applications. When this model is used, the publishing application
doesn't expect a reply.

Request/reply

Alternatively, an application may publish a
message and expect a reply either in synchronous mode (the message
can't be received until the reply is sent) or
asynchronous mode (the reply is sent after message reception).

Both publish and subscribe and request/reply messaging can behave in
a point-to-point manner if the sending application calls out which
specific application should receive a message.

Values in one application can be mapped to equivalent values in
another application by defining

domain value maps using
iStudio. Keys for corresponding entities in two
different applications can also be correlated using
iStudio.

15.1.2 iStudio Interface

The interface in the
i Studio modeling and design tool
consists of two navigation trees for design and deployment, as well
as five main menus.

Here are the navigation trees:

Design Navigation Tree

Groups objects as Common Views, Applications, Workflow, and Enabling
Infrastructure

Deploy Navigation Tree

Groups objects as Applications or Workflow

The
menus
include:

File Menu

Handles creating and opening existing projects and workspaces,
project reloading, object creation and migration, export of PL/SQL
stubs, and metadata push to adapters

Edit Menu

Handles editing, copying, deleting, versioning, or loading objects,
renaming applications, adding or removing applications from domain
value maps or cross-reference tables, and deploying events to or
editing Workflow configurations

Procedure Menu

Handles invoking or implementing procedures via wizards

Event Menu

Handles publishing or subscribing to events via wizards

Help Menu

Handles access to the iStudio User's
Guide

Figure 15-4 shows a typical view of the
iStudio interface and the Design
Navigation Tree.

Figure 15-4. Typical iStudio interface

15.1.3 Oracle Workflow for Java

The Oracle Workflow
for Java (OW4J) engine can be used with
OracleAS InterConnect to enable business
process definition, automation, and integration. Oracle Workflow for
Java enables execution of a sequence of events in a specific order.
You can view the progress of processes through these sequences via
either monitors or notification methods (for example, JMS messages
and email). The following components are part of OW4J:

Workflow Builder

Provides a graphical business process-modeling tool

Workflow Engine

Manages business process execution and exception handling

Business Event System

Provides a Java API for propagating events

Process Monitor

Used to view and administer events

Directory Service

Enables OracleAS Single Sign-On, synchronization with the Oracle
Internet Directory, and integration with LDAP

Workflow Manager

Monitors system metrics and processes, and configures and monitors
notification mailers

Business process models are typically
created using the
JDeveloper OW4J Modeler as the
Workflow Builder. Business processes might be
either short or long. Very short business processes are served by
in-memory workflows. Long-lived tasks may extend to weeks and beyond.

Version numbers are automatically assigned to workflow tasks, thus
enabling different versions of activities.

Models of these processes can be built to include logic for looping,
branching into parallel flows and rendezvous, decomposing into
subflows, branching into subtasks, and others. Escalation processes
can be created and then executed after periods of inactivity based on
predefined rules. Notification routing can also be set up to handle
typical occurrences such as delegation of responsibility or rerouting
during absence of a participant.

The Process Monitor provides a Java applet to
review business activities that have been completed, are active, or
are yet to be initiated. Decision makers are identified and their
responses are shown. Administrators can intervene to explore stopped
processes or to skip or retry processes. It is possible to review the
time and cost of business processes by exploring workflow processing
data stored in an audit database.

The Workflow Manager interface is exposed
through Oracle Enterprise Manager. Work items and event messages can
be viewed (including the distribution of event messages by status).
This interface enables administrators to more quickly determine
business bottlenecks.

15.1.4 Typical OracleAS InterConnect Deployment Sequence

A typical OracleAS InterConnect deployment sequence
includes the following steps:

Configure a source triggering mechanism (such as through Oracle AQ).

Create a new project in iStudio.

Create common view business objects in iStudio
and business object events.

Create an iStudio application in which an
adapter communicates with a business application.

Create a cross-reference table mapping keys between systems using
iStudio applications.

Create published events in iStudio that map
application views to common views, perform transformations, and
publish new events to subscribers.

Subscribe applications to events in iStudio.

Create content-based routing in iStudio if
required (e.g., routing based on message or message header contents
via Oracle Workflow with appropriate applied business logic).

Create an Oracle Workflow process bundle in
iStudio if business logic is to be applied
(including a bundle name, business process, and publish-and-subscribe
activities), and then deploy it.

Create objects in Oracle Workflow for modeling, and then model
business logic.

Deploy application queues in iStudio, and test
the integration prior to final production deployment.