Abstract
xSim is a simulation-based performance investigation toolkit that permits running high-performance computing (HPC) applications in a controlled environment with millions of concurrent execution threads, while observing application performance in a simulated extreme-scale system for hardware/software co-design. The presented work details newly developed features for xSim that permit the injection of MPI process failures, the propagation/detection/notification of such failures within the simulation, and their handling using application-level checkpoint/restart. These new capabilities enable the observation of application behavior and performance under failure within a simulated future-generation HPC system using the most common fault handling technique.