Carl Livermore carl297r

New York

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carl297r / PersistedGameOfPingPongWithSnapshots.scala

Last active August 29, 2015 13:58

A game of ping pong using two Akka Actors, persisted using Event Sourcing through Akka Persistence. Adapted from Jonas Bonér's example https://gist.github.com/jboner/9990435 to add Snapshots.

	package demo

	// Adapted from Jonas Bonér's example https://gist.github.com/jboner/9990435

	import akka.actor.{Props, ActorSystem}
	import akka.persistence.{EventsourcedProcessor, SnapshotOffer}

	object PersistedPingPong extends App {

	case object Ball //The Command

jboner / PersistedGameOfPingPong.scala

Last active March 27, 2019 16:43

A game of ping pong using two Akka Actors, persisted using Event Sourcing through Akka Persistence

	package demo

	import akka.actor.{Props, ActorSystem}
	import akka.persistence.PersistentActor

	object PingPong extends App {
	case object Ball // The Command
	case object BallReceived // The Domain Event, represents a Fact, something that have already happened

	class Ping extends PersistentActor {

jessitron / stayingDead.scala

Created March 19, 2014 15:23

Akka testing: it's a good idea to tell your actor system to leave a dead top-level actor dead. See: http://blog.jessitron.com/2014/03/testing-in-akka-sneaky-automatic.html

	// In real life, it's great that stuff gets restarted when it fails.
	// In testing, we'd rather know that it failed.

	import akka.actor._
	class DyingActor extends Actor {
	def receive = { case "die" => throw new Exception("poo") }
	}

	// Default config, everything restarts automatically
	val system = ActorSystem("ordinary")

jboner / latency.txt

Last active December 17, 2025 06:04

Latency Numbers Every Programmer Should Know

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD