NyxCache: Flexible and Efficient Multi-tenant Persistent Memory Caching

We present NyxCache (Nyx), an access regulation framework for multitenant persistent memory (PM) caching that supports light-weight access regulation, per-cache resource usage estimation and inter-cache interference analysis. With these mechanisms and existing admission control and capacity allocation logic, we build important sharing policies such as resourcelimiting, QoS-awareness, fair slowdown, and proportional sharing: Nyx resource-limiting can accurately limit PM usage of each cache, providing up to 5 x better performance isolation than a bandwidthlimiting method. Nyx QoS can provide QoS guarantees to latencycritical caches while providing higher throughput (up to 6 x vs. previous DRAM-based approaches) to best-effort caches that are not interfering. Finally, we show that Nyx is useful for realistic workloads, isolating write spikes, and ensuring that important caches are not slowed down by increased best-effort traffic.