Patterns: Information Aggregation and Data Integration with DB2 Information Integrator

94 Patterns: Information Aggregation and Data Integration with DB2 Information Integrator

򐂰 Guidelines for usage and scenario

3.5.1 Business and IT drives

As in the case of Population, any business need that requires a specialized copy

of data—derived data—from a pre-existing source may indicate the need for the

Two-way Synchronization application pattern. These needs are most often seen

in business intelligence and content search and related applications. However,

some cases are also seen in a pure operational environment, where a dedicated

copy of data is needed. The key indicator for Synchronization is that the use of

the derived data has some strong read-write characteristics.

The business and IT drivers for Two-way Synchronization are partially the same

as those listed for Population in 3.4.1, “Business and IT drivers” on page 72.

However, modern and more sophisticated business intelligence and combined

operational/informational needs such as customer relationship management

(CRM), call centers, customer portals, etc. place added requirements for

updating the derived data. These modern business processes often require that

the source and derived data are more closely synchronized than "pure" business

intelligence applications, and thus need Two-way Synchronization.

As the need for synchronization increases, the differences between the source

and derived data that can be handled decreases, because some transformations

are fundamentally unidirectional, or are time-dependent. In the limit, the IT

drivers for creating and managing a copy of the source have to be traded off

against those for having a single copy of data and accessing that distributed data

through the Federation application pattern.

3.5.2 Two-way Synchronization pattern

The Application and Runtime patterns for the Two-way Synchronization pattern

are described here.

Two-way Synchronization application pattern

Figure 3-16 on page 95 represents the Two-way Synchronization application

pattern.

Chapter 3. Data Integration and Information Aggregation patterns 95

Figure 3-16 Two-way Synchronization application pattern

Figure 3-16 shows a basic two-way synchronization of data between two

separate data stores. At a simplistic level, it can be compared to the basic

Population application pattern described in 3.4.2, “Population pattern” on

page 73, with the only difference being that data now flows in both directions.

Depending on the relationship between the data flowing in either direction, this

similarity with Population may be more apparent than real. If the data elements

flowing in both directions are fully independent, then Two-way Synchronization is

no more than two separate instances of Population. However, it is more common

to find some overlap between the data sets flowing in either direction. In this

case, the need to reconcile data updates on both source/target systems means

that the Two-way Synchronization pattern is rather more than two separate

Population instances. A significant issue in this case is conflict detection and

resolution when updates occur independently in the different data stores.

LEGEND:

Data sources are represented by disks in three different colors / shades:

Blue / plain: Read/write

Yellow / diagonal hatching: Read-only

Green / vertical hatching: Temporary

Read/write and read-only refer only to the interaction between the overall pattern and that data source

as also indicated in most cases by annotation on the linkages. In general we may assume that the

application associated with a particular data source has read/write access.

A dotted box around an application and source data indicates that the source data may need to be

accessed through the owning application via its API, or may be accessed directly via a database API.

In general, a dotted box around a number of components indicates that we are not specifying which

of those components we are interacting with.

A dashed line, arrow or component indicates an optional component.

Synchronization

Metadata

Application

Source/

Target

Application

Source/

Target

Temporary

store

Synchronization

Metadata

Application

Source/

Target

Application

Source/

Target

Application

Source/

Target

Application

Source/

Target

Temporary

store

Temporary

store