Currently, the market push is towards SOA, or Service-Oriented Architecture. SOA as a term is impressive but we need to understand what benefit we can achieve using SOA. Before turning towards benefit, it is necessary to discuss common understanding. In brief, a service oriented architecture is paradigm which include service as a layer whereas service which is nothing but individual functionality that is shared across the applications.
The primary goal of Service Oriented Architecture is to align business users with information technologies (IT).
Service-oriented architecture (SOA) enables increased business agility, improved business workflows, extensible architecture, enhanced reuse, and a longer life span of applications
Adopting Service Oriented Architecture realizes many benefits.
An underlying premise in the application of SOA to information technology is the principle of loose coupling i.e. avoiding or at least encapsulating temporal, technological and organizational constraints in the information system design.
Loosely coupled systems support late or dynamically binding to other components while running, and can mediate the difference in the component's structure, security model, protocols, and semantics, thus abstracting volatility.Loose coupling in SOA is how the services are implemented without impacting other services or application. The only interaction between the application and services is through the publish interfaces. This means application doesn’t interested how the services been implemented.
Location transparency means that the consumer of the service doesn’t care where the implementation of the services resides. It could be same server or other server across the internet. Consumer calls are agnostic to service location.
ReusabilitySOA compliance to web services and hence applications running on either platform can also consume services running on the other as web services that facilitate reuse. Properly designed implemented SOA application provide infrastructure that makes reuse possibilities in heterogeneous environment such as C,C++,Java, .Net etc.
Managed environments can also wrap COBOL legacy systems and present them as services. This has extended the useful life of many core legacy systems indefinitely, no matter what language they originally used
Since SOA confers layer based architecture therefore it breaks testing into definable testing areas such as services, security, and governance etc. These testing areas would be tested separately using best tools and approach.
For reference JUnit or NUnit allows for creation of a test suite. The test suite consists of number of procedure, each of which is designed to test a service or component. In SOA environment automation of testing is very common for frequently changing enterprise services which improve regression testing efficiency.
The other aspect of SOA testing is that testing of independent reusable service which can be tested independently which force tester to not to test the overall application unless all the service passed successfully. More and better testing usually means fewer defects and a higher overall level of quality.
Parallel DevelopmentService Oriented Architecture advocate more parallelism in development environment as SOA is based on layers based architecture. Since Service Oriented Architecture confers layer based architecture therefore it advocates more parallel development. SOA consist of inventory of contract based independent services which could be developed in parallel.
Above figure shows developers could develop independent services in parallel and services will be completed on the same schedule time. Business processes will be accessing the independent services orchestrate them and provide the concrete business functionality.
Higher Availability & Better Scalability
SOA a Multi-layered architecture can be individually clustered with appropriate load balancing to scale up the system.
As we know redundancy is the key for high availability SOA achieve redundancy by introducing redundant elements via clustering. SOA uses layer architecture to facilitate the logical decoupling that allow to design a very resilient system with each layer of the stack.The other aspect of SOA testing is that testing of independent reusable service which can be tested independently which force tester to not to test the overall application unless all the service passed successfully. More and better testing usually means fewer defects and a higher overall level of quality.
Re-routing load balancer such as F5 with server’s reverse proxy and software load balancer further increase availability and scalability in SOA environment.