October 14, 2015
The advent of fast non-volatile, main memory technologies (e.g., PCM, RRAM, or STTM) leads to new trade-offs in designing storage systems and the network protocols used to access them. Conventional application-level network protocols (e.g., the set of RPCs that constitute the NFS interface) are too slow fully exploit the low-latency these new memories offer. RDMA is a possible alternative, but its limited functionality (just read and write) means that many operations require multiple RDMA requests, each of which requires a network round trip, forfeiting any efficiency gains. Steven Swanson proposes to build a system called Remote Direct Function Access (RDFA) that will increase the flexibility of RDMA-style requests and allow more complex protocols to operate without the overhead of a conventional network stack. RDFA relies on a specialized network card that provide programmers with a flexible programming environment to implement application-specific operations that remote nodes can invoke to carry out complex operations (e.g.,inserts or lookups in a hash table). Steven Swanson will prototype the specialized NICs in FPGAs and evaluate the system in a cluster of 32 machines.