Patterns: Broker Interactions for Intra- and Inter-enterprise

66 Broker Interactions for Intra- and Inter-enterprise

3.5 Data-focused application patterns

When applications need to share information rather than coordinate processing,

data-focused application integration is more appropriate than a process-focused

approach. Note, however, that when the frequency of data update is extremely

high (for example, when integrating an order entry system with a back-end ERP

system), process integration is the best solution. When this is not the case,

however, integration of (application) data repositories is handled outside of any

specific application request.

In delineating Data-focused Application Integration patterns, two key

environmental questions should be asked:

򐂰 Is the enterprise data topology centralized or decentralized?

– Centralized: This integration effort will bring about centralized access to

all or a subset of the enterprise data model.

– Decentralized: Applications will retain their isolated repositories but now

with cohesion based on data integration.

򐂰 What is the database affinity type?

– Homogeneous: All repositories are of the same type.

– Multi-vender Relational: All repositories are relational with ODBC/JDBC

support for interoperability but are from different vendors.

– Heterogeneous Structured: repositories are not all relational, but all

have a structured layout.

– Structured/Non-Structured: The need to integrate non-structured

(for example, free-form text) with structured data sources.

Refer to the IBM Patterns for e-business Web site for further details:

http://www.ibm.com/developerWorks/patterns

3.6 Previous Application Integration patterns

Table 3-3 provides an overview of the relationship between the previous

Process-focused Application Integration patterns and the revised

Process-focused Application Integration patterns presented in this chapter:

򐂰 Direct Connection is retained for application coordinated requests.

򐂰 Transactional is now a quality of service. Transactionality may apply to all of

these patterns, so it is applied as a quality of service rather than being a

separate pattern.

򐂰 Aggregator/Broker are combined into Broker for broker coordinated requests.

Chapter 3. Application Integration pattern 67

򐂰 Managed Process is split into Serial Process and Parallel Process for process

managed coordinated requests.

򐂰 The read-only versus read/write classification used with old patterns is not

used with the new patterns, since:

– For Transactional and Managed Process, read-only is not applicable.

– For Direct Connection, the same pattern applies in both cases.

– For Aggregator/Broker, the observed patterns are identical.

Table 3-3 Relationship to old Process-focused Application Integration patterns

Old Pattern New Pattern

Information

Request (R/O)

Processing

Request (R/W)

Application

Coordinated

Direct Connection Direct Connection Same

Transactional

Coordinated

Not applicable Transactional Now a Quality of

Service

Broker

Coordinated

Aggregator Broker Broker

Process

Managed

Coordinated

Not applicable Managed Process Split into:

򐂰 Serial Process

򐂰 Parallel Process

68 Broker Interactions for Intra- and Inter-enterprise