Flow control in remote direct memory access data communications with mirroring of ring buffers

Abstract

Two computing devices utilizing remote direct memory access establish a send ring buffer on a sending computer and a receive ring buffer on a receiving computer that mirror one another. A message is copied into the ring buffer on the sending computer and a write edge pointer is updated to identify its end. The message is copied, by the sending computer, from its ring buffer into a ring buffer on the receiving computer. A process executing on the receiving computer periodically checks, at its write edge pointer, and, upon detecting the new message's header, it updates the location identified by the write edge pointer. Once the new message is copied out of the ring buffer at the receiving computer, a trailing edge pointer is updated and a process executing at the sending computer monitors the trailing edge pointer of the receiving computer and updates its own trailing edge pointer accordingly.