Towards Increased Datacenter Efficiency with Soft Memory

Memory is the bottleneck resource in today's datacenters because it is inflexible: low-priority processes are routinely killed to free up resources during memory pressure. This wastes CPU cycles upon re-running killed jobs and incentivizes datacenter operators to run at low memory utilization for safety. This paper introduces soft memory, a softwarelevel abstraction on top of standard primary storage that, under memory pressure, makes memory revocable for reallocation elsewhere. We prototype soft memory with the Redis key-value store, and find that it has low overhead.