Functions-remote: quick update with sockets and jdk21 fibers, for creating very high throughput api's

kostaskougios · November 20, 2023, 5:53pm

functions-remote is an experimental library that makes remote functions calls (almost) as easy as calls on the same jvm. I’ve added a socket + fibers implementation that works on jdk21. It is a lot faster than an http server and due to the fibers there is no blocking with a very simple programming model (no IO monads, “lets make scala simple again” ).

Because there is no http overhead, it is more than 10x faster to do a remote call than i.e. http4s. And due to fibers, it all as if the call is local with no blocking but a straight forward return type.

github.com

kostaskougios/functions-remote-examples/blob/main/docs/sockets.md

# Sockets and fibers for api's that don't require http

This is best for 
- Very simple code, no IO frameworks, where calls seem synchronous but there is no performance penalty for waiting the results from the server due to the fibers of jdk 21+. Tests on a macbook pro M1 that runs both client and server had 188k requests/sec throughput for a simple add(a,b):Int function compared to 15k of the same with http4s.
- Scala api's that talk to each other and don't require http to do so.
- Performance is important, i.e. 10x more throughput than http4s because there is no http-protocol overhead.

We will create a server that can serve calls to the `LsFunctions` trait with both avro and json serialization. The exported functions:

```scala
trait LsFunctions:
  def ls(path: String, lsOptions: LsOptions = LsOptions.Defaults): LsResult
  def fileSize(path: String): Long
```

Start by looking at 
- [bin/build-sockets-and-fibers](../bin/build-sockets-and-fibers) script and it's comments.
- [build.sbt](../build.sbt) , "fiber & sockets examples" section
- [The server](../ls-fiber-sockets-server/src/main/scala/example/SocketsServer.scala)
- [The client](../ls-fiber-sockets-client/src/main/scala/example/SocketClient.scala)

This file has been truncated. show original

The rest of the lib with http4s, kafka etc integrations:

tarsa · November 21, 2023, 9:47pm

Nice.

Have you tested JEP 380: Unix-Domain Socket Channels ? They do not have the overhead of TCP/IP protocol, so could be much faster. OTOH, they are tied to filesystem, so they aren’t as universal as TCP/IP based solutions. However, the interface (sockets API) is the same once you create the sockets, so probably a lot of code could be shared.

kostaskougios · November 22, 2023, 5:31pm

Thanks, no didn’t try it yet. I had a look, so this is IPC in the same box, will have a better look at some point, if it behaves in a similar way like sockets it would be easy to plug in. For now I am working on helidon http/fibers integration.