"Finagle is a library for building asynchronous RPC servers and clients in Java, Scala, or any JVM language.
Overview
Built atop Netty, Finagle provides a rich set of tools that are protocol independent.
Finagle is flexible enough to support a variety of RPC styles, including request-response, streaming, and pipelining (e.g., HTTP pipelining and Redis pipelining). It also makes it easy to work with stateful RPC styles (e.g., those requiring authentication and those that support transactions)."