Service Oriented Architecture Michael Biden 5/11/2019 IS553 Term Paper - Biden

Service-Oriented Architecture Gartner defines as: ‘Service-oriented architecture (SOA) is a client/server software design approach in which an application consists of software services and software service consumers (also known as clients or service requesters).’ Gartner first defined SOA in 1996. The above definition is from a 2003 paper. SOA is really about the combining some existing general architectural patterns for a greater goal. Specifically SOA aims to leverage modularity and encapsulation (2 very important patterns that are commonly utilized) with loose coupling (a pattern that is not so common) 5/11/2019 IS553 Term Paper - Biden

SOA History First distributed technologies created in the during the late mini-computer era Various Messaging and RPC technologies came and went during the 1980’s and early 1990’s During this time SOA was possible, it was just not yet desirable 5/11/2019 IS553 Term Paper - Biden

SOA History con’t CORBA was first specified in 1991 as a method for OO systems to remotely access one another MS DCOM is a similar technology Gartner first defined SOA in 1996 It was possible to create a CORBA SOA. However, CORBA never gained widespread support, the design effort required to create and SOA with CORBA was immense, and it was difficult to create loosely coupled services with CORBA. 5/11/2019 IS553 Term Paper - Biden

SOA History Con’t The mid 1990’s success of the internet spurned innovation into how distributed computing could take advantage of the internet and also increased demand from management for improved interoperability between systems 5/11/2019 IS553 Term Paper - Biden

SOA History Con’t Various methods were invented for distributing computing using existing internet standard protocols For a while there was a lot of bickering between vendors regarding standards; amazingly all agreed that a form of distributed computing would be the future 5/11/2019 IS553 Term Paper - Biden

SOA History Con’t Eventually consensus was made and web services were ‘standardized’ Web Services are services that utilize the following protocols: SOAP, WSDL, and/or UDDI The ubiquity of Web Services make them a very important enabler of SOA SOAP – Simple Access Protocol  is a transmision protocol like iiop for CORBA WSDL – Web Services Definition Language  meta data protocol UDDI – Universal Description Discovery and Integration  identification and location protocol Because all important vendors agreed to these standards and because they are including them in their AD tools and in their middleware products, SOA is more possible than ever. These protocols are also simple and promote loose coupling. 5/11/2019 IS553 Term Paper - Biden

SOA Description SOA should really be called IOA for Interface-Oriented Architecture Indeed SOA is built with Services, but the more important aspect is the interfaces to those services Services have an interface and and implementation. Definition of a composite application  what you build with an SOA. The implementation is treated like a black box. The interface is very important because it is what remains coupled and it is what forms the new composite application topology. Service are also loosely coupled at design time. This means that changing the black box behind an interface will not bring down the entire composite applicatoin 5/11/2019 IS553 Term Paper - Biden

SOA Benefits Agility Focus on Business Lowers Development Costs Enables Incremental Development Clarifies Application Topology Agility  Apps can be assembled from other apps quicker than developed from scratch Focus on Business  Line of Business managers focus on a higher level due to coarse components Lower Cost  Assembly cheaper than build from scratch Incremental Development  With SOA, you can bolt on new services as necessary Clarification  Monolithic (today’s arch) left siloed departmental apps alone, now they become assets, and they are uncovered. 5/11/2019 IS553 Term Paper - Biden

SOA Benefits con’t Myths: (from Gartner) SOA does not bring these: ·         Simple software engineering ·         Free integration ·         Technology independence ·         Vendor independence ·         The ultimate architecture SOA is complex. Integration with web services is easier, but not perfect As any other IT practice, SOA is a ‘best practice’ and as such is not the ultimate architecture. Event Driven Architecture is another important and often overlooked new architecture. Since it is similar, it is often confused with SOA. Monotlitihic, SOA, and EDA will all be used in IT in the near future. 5/11/2019 IS553 Term Paper - Biden

SOA Usage Guidelines Good for: Not Good for: Multi-Channel Apps Real-Time Composite Apps Not Good for: Apps that require fast response time Apps that require high security Multi-Channel Apps  Apps that use common back ends (in SOA services) for multiple front ends (e.g. web, pda) Real-Time Composite Apps  Apps that combine many other applications to make a composite application that takes requests and makes responses in real-time 5/11/2019 IS553 Term Paper - Biden

SOA – Marketplace Almost every enterprise software vendor is offering some sort of web-services and/or SOA capability in their offerings The most important areas of development are: ISE’s SOBA’s ISE’s are like IDE’s they stand for Integrated Service Environment. They are tools that include design and development facilities for all aspects of SOA. They are in their infancy. If vendors such as MS, BEA, and IBM can create successful, stable and mature tools for SOA, SOA will succeed as a mainstream architechture SOBA’s  Service Oriented Business Applications are packaged business applications such as ERP, CRM, SCM that have SOA capabilities. These are much more mature than ISE’s. They enable enterprises to create composite applications with their offerings. 5/11/2019 IS553 Term Paper - Biden

Conclusion SOA is an important architecture. It is overhyped by media and vendors whom both profit on hype Realistic SOA maturity is likely much further away than any predictions SOA is similar to the RDBMS craze of the early 1970’s In 1970 Codd layed forth the foundation for RDBMS’s (this was real hard computational proven theory) The industry was very excited and predicted new and great databases would soon be created  in reality it took until about 1985 before RDBMS’s were viable for the enterprise. However the web services make some things like multi-channel apps and composite apps possible today, and they promote an important design principle  loose coupling. 5/11/2019 IS553 Term Paper - Biden