Maintaining the Core – Service Repository - Applied SOA Patterns on the Oracle Platform - page 337

Decentralized realization
The idea of decentralized realization is to avoid lookups of any kind and maintain the or-
chestration logic as a static process. This way, processes will be reconfigured only through
recoding and reimplementation. Simply put, this option can be described as do nothing . We
identified all the downsides of this approach at the beginning of Chapter 3 , Building the
Core - Enterprise Business Flows , when discussing the assessment of the CTU SOA solu-
tions.
The application project store
The primary goal of this realization is to establish a centralized metadata repository for all
artifacts developed within a single SOA project. This repository can support runtime look-
ups (for instance, in SCA Mediator), but for entities designed for a specific SCA, limited
by a single project or a small group of projects. The structure of metadata, its taxonomy,
and ontology will be completely at the discretion of project's team lead. You will certainly
remember the small exercise from Chapter 4 , From Traditional Integration to Composition
- Enterprise Business Services , when we implemented a basic proxy on OSB. In the first
step of this exercise, we created a common folder structure for XML-based artifacts. We
realize that many of you found it far from optimal and different from your usual classifica-
tion. This is exactly our point. A project-centric repository, based on a similar (custom) ap-
proach and maintained using Oracle Metadata Services (MDS), is extremely flexible and
convenient for a single department; however, it requires constant vigilance from SOA ar-
chitects and Governance specialists. In fact, as is, it fits most of the needs of a small depart-
ment. The positive side is that the performance of the MDS lookups (for file- and DB-
based MDS realization) is quite good. Based on the runtime lookup scenarios' individual
tables from the preceding section, we can identify the lookup types and entities as follows:
• Lookups types in use : The types are none or limited, which use the oramds pro-
tocol
• Entities maintained : The entities are none and are project specific in MDS
The first approach in project-based SR realization is straightforward:
• The first and second assumptions (from the General objectives section) are taken
for granted and the provisioning flow is functionally decomposed at the level
where agnostic common services are separated from the functionally complete
GU-specific business services.