distributed operating systems
TRANSCRIPT
Dionicio D. Gante, Genevev G. Dionicio D. Gante, Genevev G. Reyes & Vanylive T. GalimaReyes & Vanylive T. Galima
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DistributeDistributed d Operating Operating SystemsSystems
What is Distributed What is Distributed Systems?Systems?
Consists of several computers that do not share a memory or a clock;
The computers communicate with each other by exchanging messages over a communication network; and
Each computer has its own memory and runs its own operating system.
Distributed System is used to describe a system with the following characteristics:
Architecture of Distributed OS
What is Distributed What is Distributed Operating Systems?Operating Systems?
Definition of Distributed OSIt extends the concepts of resource management and user friendly interface for shared memory computers a step further, encompassing a distributed computing system consisting of several autonomous computers connected by a communicating network.
Issues in Distributed OS Global Knowledge Naming Scalability Compatibility Process Synchronization Resource Management Security Structuring
What are the Advantages What are the Advantages of Distributed Systems of Distributed Systems Over Traditional Time-Over Traditional Time-
Sharing Systems?Sharing Systems?
The Main Advantage of Distributed Systems is: They have a decisive price/
performance advantage over more traditional time-sharing systems
Other Significant Advantages: Resource Sharing Enhanced Performance Improved Reliability and availability Modular expandability
What are the three What are the three categories of a categories of a
distributed systems?distributed systems?
Tanenbaum and Renesse classified distributed systems into three broad categories, namely: the minicomputer model, the workstation model and the processor pool model.
Minicomputer Model Workstation Model Processor Pool Model
Categories of Distributed Systems
What is mutual What is mutual exclusion?exclusion?
Mutual exclusion is a collection of techniques for sharing resources so that different uses do not conflict and cause unwanted interactions.
What are the differences What are the differences between mutual between mutual
exclusion in a single exclusion in a single computer systems from computer systems from
distributed systems?distributed systems?
What is the primary What is the primary objective of mutual objective of mutual
exclusion?exclusion?
To maintain mutual exclusion; that is, to guarantee that only one request accesses the critical section at a time.
What are the What are the characteristics important characteristics important
in mutual exclusion?in mutual exclusion?
Characteristics are considered Characteristics are considered important in a mutual exclusion important in a mutual exclusion algorithm:algorithm: Freedom from Deadlocks Freedom from Starvation Fairness Fault Tolerance
How to measure the performance The number of messages necessary
per CS invocation. The synchronization delay The response time
Thank you for listening Thank you for listening and for not asking and for not asking
questions!questions!