Distributed System Architecture Types

•Minicomputer Model
•Workstation Model
•Workstation – Server Model
•Processor Pool Model
•Hybrid Model

•Minicomputer Model

Above model was used in mid-80's. Mini computers will be serving different terminals. For instance, If  UserA is assigned with a machine which is being served by MINI-COMPUTER A and there are interconnected MINI-COMPUTERS say B,C & D. each MINI COMPUTER has 3 users then You can login only to the computer which is being servered by MINI COMPUTER A.

Major resources like Memory or Local Disk is centralized at MINI COMPUTER. 

EX: Unix based systems.

•Workstation Model

Each user is assigned with a Work station. And it is more like Advanced version of MINI COMPUTER model. In this model Each WORK STATION will be capable of holding calculations. And each WORKSTATION Serves "single user".

Workstation – Server Model

In above, WORK STATION will be dedicated to the users. So each WORK STATION Serves single user. But MINI COMPUTER will act as server and each MINI COMPUTER Services can be shared among the WORK STATIONS. 

EX: Printer is installed on one MINI COMPUTER Server. This can be used across the Workstations.

•Processor Pool Model

This is again extension for WORKSTAION SERVER Model. In this model SERVER's are combined into a pool. When a request comes from the user it will be handled by the pool on servers based on availability. 

•Hybrid Model

• Based upon workstation-server model but with additional pool of processors
• Processors in the pool can be allocated dynamically
• Gives guaranteed response time to interactive jobs
• More expensive to bui