USING ACTORS FOR THE INTERNET OF (LEGO) TRAINS

Johan Janssen, Info Support @johanjanssen42

Disclaimer: No Lego was harmed beyondrepair during the project.

CONTENT

Why? Getting started Architecture Actors Remote actors

Shared protocol HTTP vs Actors Conclusion Challenges Questions

WHY?

Why?

GETTING STARTED

MINIMAL INGREDIENTS FOR 1 TRAIN ABOUT € 50Raspberry Pi A+ / Raspberry Pi ZeroWifi dongleEDUP Ultra-Mini Nano USB 2.0 802.11n

USB battery packAnker® 2. Gen Astro Mini 3200mAh

Infrared transmitterKeyes 38KHz IR Infrared Transmitter Module for Arduino

COMPARISONIdle (mA) Memory

(MB)CPU (Mhz) Size (mm)

RPi A+ 100 256 700 65 *56 RPi Zero 100 512 1000 65 * 30RPi B+ 200 512 700 85 *56RPi 2 B 230 1024 4*900 85 *56Odroid C1

325 1024 4*1500 85 *56

Particle Photon

80-100 128KB 120 38 * 21

ARCHITECTURE

Architecture

LTCC(Angular)

LTCC(Java)

DeviceControl(Java)

Infrared(C and LIRC)

RFID(C)

SwitchControl(Java)

Servo(Python)

RPi-Cam-Web-Interface(C)

LTCC(Angular)

LTCC(Scala/Akka)

DeviceControl(Scala/Akka)

Infrared

(C and LIRC)

RFID(C)

SwitchControl(Scala/Akka)

Servo(Python)

Leds with Photon

(C)

RPi-Cam-Web-Interface(C)

LTCC (Laptop / Pi)

Lego Train

SwitchControl (Pi) Camera (Pi)

DeviceControl (Pi)

Original controls

Infrared

Sound

Camera

Switches

LTCC APPLICATION

ACTORS

AKKA ACTORSclass Worker extends Actor { def receive = { case x => println(x) }}

val system = ActorSystem("ExampleActorSystem")

val workerActorRef = system.actorOf(Props[Worker])workerActorRef ! "Hello conference"

REMOTE ACTORS

AKKA REMOTE ACTOR CALL

val workerActorRef = system.actorOf(Props[Worker])

val workerActorRef = system.actorSelection("akka.tcp://ExampleActorSystem@127.0.0.1:9005/user/workerActor")

AKKA REMOTE ACTOR CONFIGURATION

akka { actor { provider = "akka.remote.RemoteActorRefProvider" } remote { enabled-transports = ["akka.remote.netty.tcp"] netty.tcp { hostname = "127.0.0.1" port = 9002 } }}

SHARED PROTOCOL

Actor on JVM 1

Actor on JVM 2

Messages

Actor on laptop

Musicservice Actor

on Raspberry

PiPlay

message

CONCRETE EXAMPLE

Serverapplication

MessageProtocol

Raspberry Pi application

EXAMPLE MESSAGE

object MusicServiceMessage { case class Play(filename: String) case class MusicList(filenames: List[Song]) }

MESSAGE USED BY APPLICATION

val actorRef = context.actorSelection("akka.tcp://[Actorsystem]@[IP]:[port]/user/musicservice")

actorRef ! [packagename].MusicServiceMessage.Play(filename)

HTTP VS REMOTE ACTOR

ADVANTAGES REMOTE ACTORS

No converting to JSON/SOAPMore natural programming

Concurrent on defaultBuilt-in load balancerBuilt-in circuit breaker

ADVANTAGES HTTP

Indepedent of technology Loosely coupled

FAT JAR (SBT ASSEMBLY) IN MB

Local actor Remote actor Akka HTTP Spring boot0

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GATLING

class ExampleSimulation extends Simulation { val scn = scenario("My scenario").repeat(100) { exec( http("Ping") .get("http://localhost:8080/ping") .check(status.is(200)) ).pause(100 millisecond) // Optional }

setUp(scn.inject( rampUsers(1000) over (10 seconds) // Changing ))}

PERFORMANCE TEST SETUP

JVM 1Akka HTTP

HTTP: /ping

pong JVM 2Akka HTTP

HTTP: /pong

pong

JVM 1Akka HTTP

HTTP: /ping

pongJVM 2

Akka remote actor

Akka over TCP: pong

pong

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Mean response time (ms)

Akka HTTP Remote actor

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Max response time (ms)

Akka HTTP Remote actor

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99 percentile (ms)

Akka HTTP Remote actor

GRADUATION STUDENT

REST could handle around 600 usersRemote actors probably around 3300 users

REST is dead, long live remote actors!

- Johan Janssen

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Remote actor Spring boot

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Max response time (ms)

Remote actor Spring boot

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99 percentile (ms)

Remote actor Spring boot

Challenges

DO IT YOURSELF https://github.com/johanjanssen/

LCC LCCInstallScript

CONCLUSION

The best part!!

QUESTIONS?Johan Janssen, Info Support @johanjanssen42