44 Broker Interactions for Intra- and Inter-enterprise
Performance
High volume workloads are often experienced in the intra-enterprise integration
domain, so there is a generally a need to carefully assess the expected workload
and to plan for future growth in workload.
Standards compliance
Rather than using different approaches for each application integration exercise
that an organization performs, standards need to be identified and applied in
order to control development and integration costs.
Private standards are also acceptable when beneficial. Adopting WebSphere
MQ, for example, as intra-enterprise message-oriented middleware provides
assured, once-only delivery messaging that can be widely used across the
organization.
Transactionality
Transaction services are often important in intra-enterprise application
integration scenarios in order to preserve data integrity and to avoid data loss.
Consider using transaction management products that work with XA compliant
resource managers to provide a commit and rollback facility, ensuring that either
all resource updates are completed or all updates are rolled back.
3.4.1 Direct Connection application pattern
The Direct Connection application pattern represents the simplest interaction
type and is based on a 1-to-1 topology. It allows a pair of applications within the
organization to directly communicate with each other. Interactions between a
source and a target application can be arbitrarily complex. Generally, complexity
can be addressed by breaking down interactions into more elementary
interactions.
More complex point to point connections will have modeled connection rules
such as business rules associated with them, as shown in Figure 3-2.
Connection rules are generally used to control the mode of operation of a
connector depending on external factors. Examples of connection rules are:
? Business data mapping rules (for adapter connectors)
? Autonomic rules (such as priority in a shared environment)
? Security rules
? Capacity and availability rules