1 / 11

CSE-591: Term Project

CSE-591: Term Project. Self-stabilizing Network Algorithms by Tridib Mukherjee ASU ID : 993-76-1704. Self-stabilization. Introduced by Dijkstra in 1974 Brings the system back to a valid state from any arbitrary initial state

yolanda-terrell
Download Presentation

CSE-591: Term Project

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CSE-591: Term Project Self-stabilizing Network Algorithms by Tridib Mukherjee ASU ID : 993-76-1704

  2. Self-stabilization • Introduced by Dijkstra in 1974 • Brings the system back to a valid state from any arbitrary initial state • Used for tolerating intermittent and unpredictable transient faults • Network Algorithms • Token Rings • Spanning Trees • Network Resets

  3. Top Level State Diagram Self-stabilization (Closure) Faults in the network Valid System State Invalid System State Self-stabilization (Convergence) Self-stabilization (Convergence) System Start-up

  4. Diajkstra’s Definition • Privilege • Boolean predicate which is true in at least one process in the system • Authorizes a process to make a move • Action • Legal system (global) state • There must be at least one privilege in the system • During an infinite time every process should be able to receive a privilege an infinite number of times

  5. Network Algorithms • Network Spanning Trees • The basic network architecture for routing and token passing • Broadcasting, Multicasting Operation • A privileged action is executed if a fault occurs in a node • Multicast trees for mobile ad-hoc networks • Counter Flushing • Used for network resets • Can be used in token Rings or trees using PIF

  6. Valid Spanning Tree Level 1 0 Level 2 1 2 Level 3 3 4 5 6 Level 4 7 8 Root Node (Source Node) Leaf Nodes (Group Members)

  7. Invalid Spanning Tree 0 1 2 3 4 5 6 7 8 Root Node (Source Node) Leaf Nodes (Group Members)

  8. First Step of Stabilization Level 1 0 1 2 3 4 5 6 7 8 Root Node (Source Node) Leaf Nodes (Group Members)

  9. Subsequent Stabilization Step(Constitutes the valid tree in this case) Level 1 0 Level 2 1 2 Level 3 3 4 5 6 Level 4 7 8 Root Node (Source Node) Leaf Nodes (Group Members)

  10. Practical Issues • Stabilization Time • Can be reduced by proper scheduling • Optimized by the use of Fault-containment • Contains the effect of faults • Scheduling is implicit • Service Unavailable during the time of stabilization • Increases end-to-end latency for the network service • Effects of faults are unnecessarily propagated through the network • Mobile Ad hoc networks & Sensor Networks • Energy Efficiency • Periodic information exchange can expensive

  11. Questions??

More Related