System Integration
Hub-and-Spoke Integration Disadvantages
Additional overhead and latency Scalability can be limited because of all burden is on the Hub
SOA Based Integration Advantages
Allows maximum flexibility and reusability; Reduces development cost;
Web Applications Architecture
Web Application Layers: Web Clients Web Server Application Server EIS (database, ERP, ...)
Integration Infrastructure
A collection of common facilities and services to support enterprise integration: Network services Meta-data repository Middleware: containers, messaging, adapters, service bus ... Security services Directory and naming services Job scheduling and management systems System management and monitoring
Elements of Systems Integration
Business Architecture and Domain Subject Architecture and Patterns (Point to point; Hub and spoke; SOA; Sync & Async) Integration Infrastructure (Meta-data; Messaging; Enterprise service bus); Standards and Governance;
Major Components of Web Platform
Client Browser - allow users to consume contents Web Servers - to generate and host contents Connectivity - deliver contents Communications Protocol - allows clients and servers to talk to each other
Why Standards?
Consistence Interchangeability Plug-and-play Support and Maintainability Vendor independence
Hub-and-Spoke Integration Advantages
Decouples sending and receiving applications and allow them to change independently.
Point-to-Point Integration Characteristics
Direct, tightly-coupled connections between two systems; Specialized interface developed for specific purpose; Requires intimate knowledge about format of information to be exchanges.
Characteristics of Integration Architecture
Distributed Computing Standards Components based Reuse and Sharing Decoupling/Loose-Coupling Configurability Extendibility and Scalability
Characteristics of Enterprise Information System (EIS)
Enterprise Grade System Business Critical Impact Multiple Business Units and Processes Requires High Quality of Service Handles Large Volume of Data
Challenges to Systems Integration
Distributed Computing; Multiple Operating Systems; Different Databases; Different Programming Languages; Large Number of Interfaces; Inconsistent Data Types and Formats; Different Application Architecture;
Challenges for system integration
Distributed computing; Multiple OS; Different dB's; Different programing languages; Large number of interfaces; Inconsistent data types and formats; Different application architecture
Levels of Integration - Extended enterprise integration
Enable collaboration beyond enterprise (with partners, suppliers, ...)
Levels of Integration - Application level integration
Enable sustainable interoperations between diverse applications with stable well-defined interfaces
Technical Objectives of Integration
Establish a clear vision and direction for evolution of enterprise systems and technologies; Standardize and streamline enterprise level systems and data architecture; Reduce ripple effects of system changes; Harmonize collaboration and integration between diverse systems and applications; Improve effective utilization of IT resources; Enable agile business via agile IT; Turn IT into a strategic business partner;
Point-to-Point Integration advantages
Fast and efficient
Benefits of Application Servers
Housekeeping services provided by application servers relieve application developers from low level system programming and let them focus on business logic and functionality. Applications can be easily ported between different application server as long as the same standards are followed: written once, run anywhere. This also prevents vendor lock-in. Separate layer offers more flexibility and scalability. Enables effective management and monitoring of enterprise applications and components across the enterprise.
Hub-and-Spoke Integration Characteristics
Hub acts as the middleman (middleware) when applications communicate with each other. Usually implemented with a Message Broker. Centralized monitoring and control because all message transformation, routing, mapping, are done in the Hub.
Importance of bD design
Importance of data; dB design defines the domain of the applications; a well designed dB is critical for the function and performance of applications;
Enterprise Technology Landscape
Infrastructure: Network, data center, HW, BCDR, security, systems management; Enterprise Information Systems; Reporting, data warehouse, data mining, and business intelligence; Middleware and Messaging; Shared services; Client and mobile platforms; Industry specific applications; Governance and policies;
Levels of Integration - Business process integration
Integration and orchestration between different business processes to provide seamlessly unified services to customers
SOA Based Integration Characteristics
Integration processing distributed among end points; Technology independent services allows plug-and-play (Lego); Use of adapters and Enterprise Service Bus (ESB);
Loose-Coupling
Interfaces based on semantics rather than syntax; Conform to standards; Asynchronous integration; Utilize integration middleware;
Classic Problems of IT
Lack of coherent, well defined enterprise architecture; Silos and stovepipes of systems; Redundant data across different systems out of sync; Customized, ad-hoc, point-to-point integrations difficult to reuse; Duplication of functionalities; Error prone manual interventions; Tightly-coupled and monolithic code result in fragile systems that are hard and awkward to change; Lack of standards and processes for technology selection and adoption;
Web Platform Disadvantages
Less functionality compared to fat client/server applications such as rich UI Security concerns
Loose-Coupling benefits
Minimize interdependence among systems; Time; Information format; Technology; Reduce ripple effects and enable plug-and-play.
Point-to-Point Integration disadvantages
Number of connections and complexity grow exponentially; Interdependence causes ripple effects and hard to change; High maintenance cost;
Business Objectives of Integration
Provide unified executive view of enterprise. Provide integrated, streamlined service to customers. Improve operations efficiency by sharing information, resources, and services. Enable business to adapt to changes of market and competitive forces - Faster time-to-market.
Features of Application Servers
Provides runtime environment to enterprise applications and components; Provides capability for managing and monitoring applications and components - deploying, starting, stopping, replication, access control ...; Provides low level system support services such as memory management, logging, transaction, security, etc.; Highly scalability and availability with advanced features such as clustering, load balancing, workload management, and session persistence, etc.
SOA Based Integration Disadvantages
Requires investment and can be hard to make the paradigm shift; Something got to give (performance, limitations);
Advantages of Layered Architecture
Specialization of application components Flexibility of deployment Loose-coupling Scalability
Levels of Integration - Data level integration
Understand semantics and syntax of each data source. Identify redundant and inconsistent data Define standard data dictionary Develop tools for data transformation, sharing, and analysis
Web Platform Advantages
Universal existence of web browsers No need for separate versions for different platforms Central update and maintenance. No client software to distribute, install, and upgrade Extend the traditional corporate boundaries
dB design steps
identify the domain objects, which will be modeled with dB tables; Deciding data elements (data dictionary); define the relations between data objects (ERD); Perform/examine normalization of data relations; Entity=data object=table