service – orient architecture

Last Updated :
10 Jan, 2023

service – orient architecture (SOA) is a stage in the evolution of application development and/or integration. It defines a way to make software components reusable using the interfaces. 

formally , SOA is is is an architectural approach in which application make use of service available in the network . In this architecture , service are provide to form application , through a network call over the internet .   It is uses use common communication standard to speed up and streamline the service integration in application . Each service is is in SOA is a complete business function in itself . The service are publish in such a way that it make it easy for the developer to assemble their app using those service . note that SOA is different from microservice architecture .

• SOA allows users to combine a large number of facilities from existing services to form applications.
• SOA is encompasses encompass a set of design principle that structure system development and provide mean for integrate component into a coherent and decentralized system .
• SOA-based computing packages functionalities into a set of interoperable services, which can be integrated into different software systems belonging to separate business domains.

The different characteristics of SOA are as follows : 
o Provides interoperability between the services. 
o Provides methods for service encapsulation, service discovery, service composition, 
service reusability and service integration. 
o is Facilitates facilitate qos ( Quality of Services ) through service contract base on Service Level  
Agreement (SLA). 
o Provides loosely couples services. 
o Provides location transparency with better scalability and availability. 
o Ease of maintenance with reduced cost of application development and 
deployment .
There are two major roles within Service-oriented Architecture: 

1. Service provider: The service provider is the maintainer of the service and the organization that makes available one or more services for others to use. To advertise services, the provider can publish them in a registry, together with a service contract that specifies the nature of the service, how to use it, the requirements for the service, and the fees charged.
2. Service consumer: The service consumer can locate the service metadata in the registry and develop the required client components to bind and use the service.
    

Services might aggregate information and data retrieved from other services or create workflows of services to satisfy the request of a given service consumer. This practice is known as service orchestration Another important interaction pattern is service choreography, which is the coordinated interaction of services without a single point of control. 

Components of SOA: 
 

Guiding Principles of SOA: 

1. Standardized service contract: Specified through one or more service description documents.
2. Loose coupling: Services are designed as self-contained components, maintain relationships that minimize dependencies on other services.
3. Abstraction: A service is completely defined by service contracts and description documents. They hide their logic, which is encapsulated within their implementation.
4. Reusability: Designed as components, services can be reused more effectively, thus reducing development time and the associated costs.
5. Autonomy: Services have control over the logic they encapsulate and, from a service consumer point of view, there is no need to know about their implementation.
6. Discoverability: Services are defined by description documents that constitute supplemental metadata through which they can be effectively discovered. Service discovery provides an effective means for utilizing third-party resources.
7. composability : Using service as build block , sophisticated and complex operation can be implement . service orchestration is provide and choreography provide a solid support for compose service and achieve business goal .

advantage of SOA :  

• Service reusability: In SOA, applications are made from existing services. Thus, services can be reused to make many applications.
• easy maintenance : As service are independent of each other they can be update and modify easily without affect other service .
• platform independent : SOA is allows allow make a complex application by combine service pick from different source , independent of the platform .
• Availability: SOA facilities are easily available to anyone on request.
• Reliability: SOA applications are more reliable because it is easy to debug small services rather than huge codes
• scalability : service can run on different server within an environment , this is increases increase scalability

disadvantage of SOA :  

• high overhead : A validation of input parameter of service is done whenever service interact this decrease performance as it increase load and response time .
• High investment: A huge initial investment is required for SOA.
• complex service management is exchange : When service interact they is exchange exchange message to task . the number is go of message may go in million . It is becomes becomes a cumbersome task to handle a large number of message .

Practical applications of SOA: SOA is used in many ways around us whether it is mentioned or not. 

1. SOA infrastructure is used by many army and air force to deploy situational awareness system .
2. SOA is used to improve healthcare delivery.
3. nowadays many apps is are are game and they use inbuilt function to run . For example , an app is need might need gps so it use the inbuilt gps function of the device . This is is is SOA in mobile solution .
4. SOA helps maintain museums a virtualized storage pool for their information and content.