SOA Overview

Building new applications that integrate business logic and application data within the enterprise and between suppliers, partners and customers is critical to the success of today’s new economy enterprises. However, such integration endeavors remain complex, expensive and risky. Service-Oriented Architecture (SOA) is the next wave of application development. SOA lets heterogeneous environments and applications exist while leveraging existing applications and infrastructure. This fosters code reuse, reducing costs and risks while speeding time-to-market.

A Service-Oriented Architecture leverages open standards to represent virtually all software assets as services, including legacy applications, Commercial-Off-The-Shelf (COTS) systems, Custom development applications, J2EE/ .NET components, CORBA objects, EDI and Web Services, to name a few. Such an approach provides a user with a standards way for representing and interacting with software assets without spending time working with unique interfaces and low-level APIs.

Using the new SOA paradigm helps reduce complexity, cost and risk of integration by providing a single, simple architectural framework based on Web Services, in which to build, deploy and manage application functionality. In other words, Service-oriented architectures allow enterprises to do more with less. How does it happen?

SOA the need and evolution

Service-Oriented Architecture are an evolutionary phenomenon and while the basic idea has been around for sometime now, actual implementations have failed. This is primarily because of three main issues –

Firstly, older approaches to SOAs such as CORBA, DCOM etc, were tightly coupled, meaning that a Service provider was closely tied to a Service Consumer. Such tight coupling meant that changes to service providers and consumers were difficult, given the in-depth planning and co-ordination required.

Secondly, such SOAs were proprietary leading to vendor lock-in for specific implementations. This also resulted in non-interoperable solutions that were not very amenable to large-scale changes or integration endeavors.

Finally, the SOAs of then were fine grained, which means that service requests and responses typically contain small amounts of specific information, requiring many round trips between the consumer and the provider of the service leading to excessive network bandwidth consumption and poor response times.

Thus the search for a truly flexible, interoperable architecture continued despite the failure of traditional SOA attempts, given that the concept of service orientation to make sense.
It is within this architectural context that Web services were first imagined. Web services are an open, coarse grained, standards-based way of creating and offering software services

Advantages of SOAs

SOAs offer the following advantages over traditional approaches to distributed computing –

	They offer business services across the platforms
	They provide location independence
	Services need not be at a particular system or particular network
	Completely loosely coupled approach
	Authentication and authorization support at every level
	The search and connectivity to other services is dynamic

Click here to read more about the Technical Architecture of a typical SOA.

Know more

Click here to read more about BPEL 4WS – the engine that drives Web Services. Click here to read a case study highlighting a practical implementation of a Web Services solution. Click here to learn more about ACS's world class products for implementing SOA .