Optimizing Interrupt Handling Performance for Memory Failures in Large Scale Data Centers

Intermittent hardware failures are generally non-catastrophic and typical large-scale service infrastructures are designed to tolerate them while still serving user traffic. However, intermittent errors cause performance aberrations if they are not handled appropriately. System error reporting mechanisms send hardware interrupts to the Central Processing Unit (CPU) for handling the hardware errors. This disrupts the CPU's normal operation, which impacts the performance of the server. In this paper, we describe common intermittent hardware errors observed on server systems in a large-scale data center environment. We discuss two methodologies of handling interrupts in server systems - System Management Interrupt (SMI) and Corrected Machine Check Interrupt (CMCI). We characterize the performance of these methods in live environments as compared to prior studies that used error injection to simulate error behavior. Our experience shows that error injection methods are not reflective of production behavior. We also present a hybrid approach for handling error interrupts that achieves better performance, while preserving monitoring granularity, in large scale data center environments.