L7 - Service-oriented System Integration Flashcards
Lecture Goals
Overview of Service-Oriented System Integration (SoSI)
How Service-Oriented Architecture (SOA) meets SoSI
Enterprise Service Bus (ESB) and Adapter integration middleware
What is Service-Oriented System Integration (SoSI)?
Allows enterprises to share distributed software functionality through services.
Originates from solutions like RPC (Remote Procedure Call).
Modern solutions use SOA principles:
Web services
RESTful services
Microservices architecture
Advantages of SoSI
Standardized functional interface (language & platform independent).
Scalability through ESB integration middleware.
Disadvantages of SoSI
Legacy systems must be adapted for service-oriented integration.
Requires greater effort than simple information integration.
RPC (Client/Server Architecture)
Shares data and functionality between service consumer (client) and service provider (server).
Uses WSDL files to define service interfaces.
Marshalling & Unmarshalling
Marshalling: Converts objects/parameters into a transmittable format (XML, JSON, binary).
Unmarshalling: Converts received data into a usable format for the system.
Object Request Broker (ORB)
Supports loose coupling in service communication.
Enables multipoint integration, leading to the Enterprise Service Bus (ESB).
Why is Enterprise Service Bus (ESB) Needed?
Traditional point-to-point integration is not scalable (N(N-1)/2 connections).
ESB provides a middleware solution to integrate multiple applications efficiently.
ESB Benefits
Scalability: Multi-point connections & routing.
Heterogeneity: Protocol and message transformation.
Loose Coupling: Services don’t need direct connections.
ESB Communication Protocols
Supports diverse protocols: HTTP, HTTPS, JRMP, IIOP, JMS.
Provides protocol transformation to ensure integration compatibility.
ESB Deployment Patterns
Global ESB – Single ESB for the entire enterprise.
Directly Connected ESBs – Multiple ESBs with a shared registry.
Federated ESB – Master ESB controls access for subordinate ESBs.
Brokered ESB – A broker mediates between multiple ESBs.
ESB in a Distributed Enterprise
A federated ESB is useful for organizations with multiple branches.
HQ ESB acts as an adapter to coordinate service updates and versioning.
What is Service-Oriented Architecture (SOA)?
An architectural style for designing service-oriented systems.
Services communicate over a network using standardized protocols.
SOA Process Flow
- Service consumer identifies required functionality.
- Service registry returns matching services.
- Service consumer selects the best service.
- Service consumer invokes the service endpoint.
- Service provider processes the request & sends a response.
- Service consumer receives and utilizes the response.
SOA Design Principles
Contracts: Defines service capabilities, vocabulary, and policies.
Discoverability: Services are registered in a central directory.
Loose Coupling: Minimizes dependencies between service components.
Statelessness: Services do not retain state between transactions.
Composability: Services can be combined to create complex workflows
What are Adapters?
Enable integration between enterprise applications and middleware.
Common types:
- Database Adapters: Oracle, MySQL, SQL Server.
- Messaging Adapters: AMQP, JMS, Kafka.
- ERP/CRM Adapters: SAP, Office24Seven.
- File System Adapters: JSON, XML, CSV, FTP.
- API Adapters: SOAP, REST, HTTP.
Adapter Communication Types
Request Processing: Adapter retrieves information when requested.
Event Processing: Adapter detects system events and forwards them.
Wrappers
Used when an application doesn’t support standard integration methods.
Acts as a mediator between legacy systems and modern service-based environments.
Performs:
Data Transformation (e.g., binary → XML → JSON).
Protocol Mediation (e.g., SOAP → REST)
Example Service-Oriented Solutions
24SevenOffice
- Cloud-based ERP system for small & medium businesses.
- No installation required.
- Pay-per-user/month pricing.
Google Apps
- Customizable suite of workgroup services.
- Pay-per-user/month or free for educational institutions.
