Netpoll is a high-performance non-blocking I/O networking framework, which focused on RPC scenarios, developed by ByteDance.

RPC is usually heavy on processing logic and therefore cannot handle I/O serially. But Go's standard library net is designed for blocking I/O APIs, so that the RPC framework can only follow the One Conn One Goroutine design. It will waste a lot of cost for context switching, due to a large number of goroutines under high concurrency. Besides, net.Conn has no API to check Alive, so it is difficult to make an efficient connection pool for RPC framework, because there may be a large number of failed connections in the pool.