LIGHTWEIGHT INPUT/OUTPUT PROTOCOL

摘要

A method and system for offloading I/O processing from a first computer (Fig. 1, 101) to.a second computer (121), using RDMA- capable network interconnects, are disclosed. The method and system include a client (103) on the first computer (101) communicating over an RDMA connection (117) to a server (123) on the second computer (121) by way of a lightweight input/output (LWIO) protocol. The protocol generally comprises a network discovery phase followed by an I/O processing phase. During the discovery phase, the client (103) and server (123) determine a minimal list of shared RDMA-capable providers. During the I/O processing phase, the client (103) posts I/O requests for offloading to the second machine (121) over a mutually-authenticated RDMA channel (117). The I/O model is asymmetric, with read operations being implemented using RDMA and write operations being implemented using normal sends. Read and write requests may be completed in polling mode and in interrupt mode. Buffers are managed by way of a credit mechanism.