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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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