kaaquist

Podman with docker-compose on MacOS.

Podman an alternative to Docker Desktop on MacOS

Getting podman installed and started is super easy.
Just use brew to install it.

> brew install podman

Now since podman uses a VM just like the Docker Client on MacOS we need to initialize that and start it.

djspiewak

Schedulers

As Cats Effect is a runtime system, it ultimately must deal with the problem of how best to execute the programs which are defined using its concrete implementation (IO). Fibers are an incredibly powerful model, but they don't map 1:1 or even 1:n with any JVM or JavaScript construct, which means that some interpretation is required. The fashion in which this is achieved has a profound impact on the performance and elasticity of programs written using IO.

This is true across both the JVM and JavaScript, and while it seems intuitive that JavaScript scheduling would be a simpler problem (due to its single-threaded nature), there are still some significant subtleties which become relevant in real-world applications.

JVM

IO programs and fibers are ultimately executed on JVM threads, which are themselves mapped directly to kernel threads and, ultimately (when scheduled), to processors. Determining the optimal method of mapping a real-world, concurrent application down to kernel-level thr

claudio-scandura

import akka.actor.{Actor, ActorSystem, Props}
import akka.http.scaladsl.Http
import akka.http.scaladsl.model.StatusCodes
import akka.http.scaladsl.model.sse.ServerSentEvent
import akka.http.scaladsl.server.Directives._
import akka.http.scaladsl.server.Route
import akka.stream._
import akka.stream.scaladsl.{BroadcastHub, Keep, Source, SourceQueueWithComplete}

import scala.concurrent.ExecutionContext.Implicits.global

djspiewak

Thread Pools

Thread pools on the JVM should usually be divided into the following three categories:

1. CPU-bound
2. Blocking IO
3. Non-blocking IO polling

Each of these categories has a different optimal configuration and usage pattern.