Comparison of Aperiodic Checkpoint Placement Algorithms

In this article we summarize some aperiodic checkpoint placement algorithms for a software system over a finite operation-time horizon, and compare them in terms of computational accuracy. The underlying problem is formulated as a maximization of steady-state system availability and is to determine the optimal aperiodic checkpoint sequence under the assumption that the system failure occurs in accordance with a non-exponential distribution. In a numerical example with Weibull system-failure time distribution, it is shown that the approximate solutions tend to underestimate the resulting system availability.