20-04-2012, 01:17 PM
DISTRIBUTED COMPUTING
DOC-Lecture.ppt (Size: 890.5 KB / Downloads: 48)
Definition:
Parts of an application run on multiple computers simultaneously.”
The “Services” Model
Object Technology is its foundation
3-Tier Conceptual Architecture:
Presentation Services (User) (PS)
Business Services (Logic/Rules & Metadata) (BS)
Data Management Services (Database) (DS)
Conceptual Layers (not necessarily corresponding to physical locations on the network when deployed)
Partitioning supports:
Different/Distributed Development Teams
Separation of Concerns
Iterative Development (RAD, Prototyping...)
Reusability, Modularity, Portability
Deployment Flexibility:
User Accessibility & Transparency
Performance
Security
Ease of Maintenance
Paradigm
An acquired way of thinking about something that shapes thought and action in ways that are both conscious and unconscious
Paradigms are essential because they provide a culturally shared model for how to think and act
They can present major obstacles to adopting newer, better approaches
The Business Value of DOC
Significantly improved performance and flexibility
Simplified maintenance
Reduced development time
Improved potential for scalability
Improved quality, reliability and fault tolerance