Fast, Transparent Filesystem Microkernel Recovery with Ananke

We introduce Ananke, a high-performance filesystem microkernel service that provides transparent recovery from unexpected filesystem failures. Ananke does so by leveraging the unique opportunity of the microkernels, running a small amount of recovery code coordinated by the host OS at the moment of a process crash. Ananke can record key pieces of information not usually available during full-system crash recovery, enabling fast and transparent recovery for applications. Through over 30,000 fault-injection experiments, we demonstrate that Ananke achieves lossless recovery; we also show that Ananke recovers quickly, usually in a few hundred milliseconds. Through real application workloads, we show that Ananke delivers high performance in the common case; the extra work needed to detect faults and prepare for recovery incurs minimal overheads.