Fault-Tolerant Parallel Communication in the Star Network

1997 ◽  
Vol 07 (01) ◽  
pp. 57-68 ◽  
Author(s):  
A. A. Rescigno
Keyword(s):  
Fault Tolerant ◽  
Routing Algorithm ◽  
Star Graph ◽  
Star Network ◽  
Probability Of Success ◽  
Information Dispersal ◽  
Parallel Communication

In this paper we study the problem of fault-tolerant parallel routing in the star network, i.e., we assume that all processors send packets according to the prescribed protocol but some packets may fail to reach (on time) their destination. Using the Information Dispersal Algorithm (IDA) we obtain a fault-tolerant randomised routing algorithm whose probability of success is 1 - N-Θ(n), where N = n! is the number of nodes of the star graph Sn.

ADAPTIVE FAULT-TOLERANT ROUTING IN STAR NETWORKS

2001 ◽  
Vol 02 (02) ◽  
pp. 213-231 ◽  
Author(s):  
KHALED DAY ◽  
ABDEL-ELAH AL-AYYOUB
Keyword(s):  
Minimum Distance ◽  
Fault Tolerant ◽  
Routing Algorithm ◽  
Star Graph ◽  
Node Failure ◽  
Star Network ◽  
Short Period ◽  
The Hierarchical Structure ◽  
Node Connectivity ◽  
Node Failures

We take advantage of the hierarchical structure of the star graph network to obtain an efficient method for constructing node-disjoint paths between arbitrary pairs of nodes in the network. A distributed fault-tolerant routing algorithm for the star network based on this construction method is then presented and evaluated. The proposed algorithm adapts the routing decisions in response to node failures. Node failure and repair conditions may arise dynamically (at any time) provided that the total number of faulty nodes at any given time is less than the node-connectivity n - 1 of the n-star. When a message is blocked due to faulty components, the source of the message is warned and requested to switch to a different node-disjoint path. The methods used to identify the paths, to propagate failure information back to source nodes, and to switch from a routing path to another incur little communication and computation overhead. We show that if the node failures occur 'reasonably' apart in time, then all messages will be routed on paths of length δ + ε where δ is the minimum distance between the source and the destination and ε is 0, 2, or 4. In the unlikely case where more failures occur in a 'short period', the algorithm still delivers all messages but via possibly longer paths.

Fault Tolerance on Star Graphs

1997 ◽  
Vol 08 (02) ◽  
pp. 127-142 ◽  
Author(s):  
Shuo-Cheng Hu ◽  
Chang-Biau Yang
Keyword(s):  
Fault Tolerance ◽  
Fault Tolerant ◽  
Routing Algorithm ◽  
Constant Time ◽  
Multiprocessor Systems ◽  
Star Graph ◽  
Cycle Structure ◽  
Star Graphs ◽  
Broadcasting Algorithm

The capability of fault tolerance is one of the advantages of multiprocessor systems. In this paper, we prove that the fault tolerance of an n-star graph is 2n-5 with restriction to the forbidden faulty set. And we propose an algorithm for examining the connectivity of an n-star graph when there exist at most 2n - 4 faults. The algorithm requires O(n2 log n) time. Besides, we improve the fault-tolerant routing algorithm proposed by Bagherzadeh et al. by calculating the cycle structure of a permutation and the avoidance of routing message to a node without any nonfaulty neighbor. This calculation needs only constant time. And then, we propose an efficient fault-tolerant broadcasting algorithm. When there is no fault, our broadcasting algorithm remains optimal. The penalty is O(n) if there exists only one fault, and the penalty is O(n2) if there exist at most n - 2 faults.

AN ADAPTIVE HEURISTIC ALGORITHM WITH THE PROBABILISTIC SAFETY VECTOR FOR FAULT-TOLERANT ROUTING ON THE (n, k)-STAR GRAPH

2014 ◽  
Vol 25 (06) ◽  
pp. 723-743 ◽  
Author(s):  
CHIAO-WEI CHIU ◽  
KUO-SI HUANG ◽  
CHANG-BIAU YANG ◽  
CHIOU-TING TSENG
Keyword(s):  
Fault Tolerant ◽  
Average Length ◽  
Routing Algorithm ◽  
Adaptive Method ◽  
Star Graph ◽  
Safety Level ◽  
Routing Performance ◽  
Preliminary Version ◽  
Adaptive Heuristic ◽  
Probabilistic Safety

The (n, k)-star graph is a generalization of the n-star graph. It has better scalability than the n-star graph and holds some good properties compared with the hypercube. This paper focuses on the design of the fault-tolerant routing algorithm for the (n, k)-star graph. We adopt the idea of collecting the limited global information used for routing on the n-star graph to the (n, k)-star graph. In the preliminary version of this paper, we built the probabilistic safety vector (PSV) with modified cycle patterns and developed the routing algorithm to decide the fault-free routing path with the help of PSV. Afterwards, we observed that the routing performance of PSV gets worse as the percentage of fault nodes increases, especially it exceeds 25%. In order to improve the routing performance with more faulty nodes, an adaptive method of threshold assignment for the PSV is also proposed. The performance is judged by the average length of routing paths. Compared with distance first search and safety level, PSV with dynamic threshold gets the best performance in the simulations.

An efficient fault-tolerant routing algorithm in NoCs to tolerate permanent faults

2016 ◽  
Vol 72 (12) ◽  
pp. 4629-4650 ◽  
Author(s):  
Reza Akbar ◽  
Ali Asghar Etedalpour ◽  
Farshad Safaei
Keyword(s):  
Fault Tolerant ◽  
Routing Algorithm ◽  
Permanent Faults
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