Analyzing the Effect of Consistency Violation Faults in Self-Stabilizing Programs
share
Consistency violation faults s refer to faults that occur due to inconsistent reads in a shared memory program. In the execution of shared-memory, interleaving, self-stabilizing programs, s offer a trade-off. Specifically, preventing s requires processes to coordinate with each other thereby slowing the execution of each action. On the other hand, permitting s requires less coordination and faster execution of each action. However, when a occurs, it can disrupt the convergence of self-stabilizing programs. Thus, a computation of a program in the presence of s can be thought of as a contest where program actions attempt to take the program to a legitimate state whereas s could potentially this convergence. We analyze three self-stabilizing programs (token ring, coloring and maximal matching) to evaluate this contest between program transitions and s. We find that the relative cost of s is generally small, i.e., as long as a few program transitions can execute between s, the program (probabilistically) converges. We also find that the cost-distribution of s is exponential in nature in that the fraction of s with cost c exponentially decreases with c. We validate these results via simulation where we control the rate of s.
READ FULL TEXT