Additional SOA Patterns –Supporting Composition Controllers - Applied SOA Patterns on the Oracle Platform - page 602

It comes at a cost, of course, but here is an opportunity to deploy these engineered sys-
tems in cloud data centers and provide multitenant access with the Pay-As-You-Go option.
Oracle sends a clear message; investments in the Global Cloud Infrastructure will be ex-
panded in the coming years (November 2013). These intentions are supported by the fol-
lowing facts:
• The Cloud Multitenant Environment Compound pattern is based on resource
sharing, pooling, and reservation and Application Server side Pooling and Reser-
vation are quite well covered by WLS clusters and work managers. Isolated Trust
Boundaries is another pattern that supports this environment, and it can partly rely
on the Oracle Service (API) Gateway, partly because its main purpose is to
provide AAA operations and other SOA Security patterns discussed in Chapter 7 ,
Gotcha! Implementing Security Layers , at the service level, but not the network.
Most importantly, Oracle DB 12 c Enterprise Edition has now introduced a new
multitenant architecture, supporting DB resources' sharing and consolidation.
• In addition to its own SDN development efforts, in January 2014, Oracle acquired
Corente for getting into software-defined networking. Corente's products include
Cloud Services Exchange, which establishes trusted network services between
public or private cloud data centers and any location over any IP network (accord-
ing to a press release). This is a very strong move towards a complete implement-
ation of the Isolated Trust Boundaries pattern and establishment of flexible and
high-performing VM-2-VM networks. Technically, it concludes all the necessary
prerequisites for complete SOA Platform virtualization.
To ensure that the implementation of the cloud is right on the money (see the next figure),
SOA, as one of the enablers, must heavily contribute to Autonomy, Abstraction, and
Loose Coupling of the application resources that are deployed on the cloud platform. As
mentioned, task-orchestrated services have to be redundantly predeployed for automatic
scaling, as the runtime non-disruptive relocation could be rather complicated. However, if
we can assemble a complex composition at runtime using Composition controllers (Ser-
vice Brokers) from Chapter 3 , Building the Core - Enterprise Business Flows , and
Chapter 4 , From Traditional Integration to Composition - Enterprise Business Services ,
this task will be quite attainable. Individual composition members, entity and utility, and
even reasonably sized atomic task services can be provisioned dynamically from clouds
and between clouds. Composition controller, which is positioned on-premise and com-
bined with the HW Load balancer can effectively distribute the service workload between
local and cloud resources; it is implemented in the cloud and can be part of cloud balan-
cing and Burst In/Out compound patterns for SCA/OSB resources (still, HW balancers
should be considered first for atomic resources).