R2P2 - Making RPCs First-Class Datacenter Citizens

Explore a groundbreaking approach to Remote Procedure Calls (RPCs) in datacenter environments through this USENIX ATC '19 conference talk. Delve into R2P2, a UDP-based transport protocol specifically designed for RPCs that aims to improve tail latency and efficiency in datacenter communications. Learn how exposing the RPC abstraction to endpoints and networks allows for in-network RPC scheduling and enables RPCs to become first-class datacenter citizens. Discover the implementation of a novel join-bounded-shortest-queue (JBSQ) RPC load balancing policy that centralizes pending RPCs in the router and limits requests to servers with a bounded number of outstanding requests. Examine the protocol's performance through microbenchmarks, comparing it to random selection and classic HTTP reverse proxies. Gain insights into R2P2's implementation in both software middleboxes and P4 switch ASIC pipelines, and understand its impact on web index searching and Redis key-value store performance. This talk provides valuable knowledge for professionals working with datacenter applications and those interested in optimizing RPC performance at the microsecond scale.