Vegeta is a versatile HTTP load testing tool built out of a need to drill HTTP services with a constant request rate.
Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed.
The Go implementation of gRPC: A high performance, open source, general RPC framework that puts mobile and HTTP/2 first. For more information see the Go gRPC docs, or jump directly into the quick start.