Implementation of Election Algorithm of Distributed Systems in Client-Server Architecture
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This document discusses algorithms for achieving mutual exclusion in distributed systems. It describes a centralized algorithm where one process acts as a coordinator and processes request access to critical sections by sending requests to the coordinator. It also describes a token ring algorithm where a token circulates in a logical ring between processes, and only the process holding the token can access the critical section. The document compares the benefits of each algorithm, noting that the centralized algorithm maintains FIFO order while the token ring algorithm does not guarantee order but prevents starvation.
Implementation of Election Algorithm of Distributed Systems in Client-Server Architecture
- 1. Presented By – Mushfekur Rahman Implementation of Election Algorithm of Distributed Systems in Client-Server Architecture
- 2. 2 Distributed Systems • Distributed systems are networked computers or processes operating with same resources generally mentioned as CRITICAL SECTION. • Critical Section can be any shared memory or any shared data structure which can be needed to update by each process.
- 3. 3 Distributed Algorithms • Distributed Algorithms are used to solve some standard problems in Distributed Systems such as mutual exclusion, resource allocation, distributed search and so on. • Our project deals with only Mutual Exclusion Problem.
- 4. 4 Algorithms • Here we will be describing about two common algorithms to achieve mutual exclusion in Distributed Systems. 1. Centralized Algorithm 2. Token Ring Algorithm
- 5. 5 Centralized Algorithm … • One process elected as coordinator • Others send request to access into the Critical Section 1. Request resource 2. Wait for response 3. Receive grant 4. access resource 5. Release resource
- 6. 6 Centralized Algorithm … • If another process claimed resource: - Coordinator does not reply until release - Maintain queue •Service requests in FIFO order
- 7. 7 Benefits • All requests processed in order since there is no priority so FIFO order is maintained • Easy to implement, understand and verify
- 8. 8 Token Ring Algorithm • Assume known group of processes - Some ordering can be imposed on group - Construct logical ring in software - Process communicates with neighbor
- 9. 9 Token Ring Algorithm … • Initialization -Process 0 gets token for resource R • Token circulates around ring - From Pi to P(i+1)mod N • When process acquires token - Checks to see if it needs to enter critical section - If no, send ring to neighbor - If yes, access resource •Hold token until done
- 10. • Only one process at a time has token – Mutual exclusion guaranteed • Order well-defined – Starvation cannot occur • If token is lost (e.g. process died) – It will have to be regenerated • Does not guarantee FIFO order – sometimes this is undesirable 10 Token Ring Algorithm …
- 11. THANK YOU !!! 11