Actor Model in Ruby

Celso Crivelaro@celsocrivelaro

http://crivelaro.me1

DEVELOPER @

PROFESSOR @

My problem

Authorization

APIs

SMTP Protocol

Strange ProtocolStrange Lib

5

Strange Protocol / Strange Lib => Unmaintained

Bad documentation

Troubleshooting was impossible

Authorization

APIs

TCP/IP

Custom Protocol

SMTP Protocol

High Concurrency ~ 1000 connections

Fault Tolerant

Easy TCP Server API

Actors Reactor

10

Actor Model Theory

Actor 1Mailbox

Actor 2Mailbox

Actor 3Mailbox

Actors are similar to Objects

Send messages to each other

Asynchronous

Actors Objects

Synchronous

Create new ones

Isolated Share memory

Keep state

Actors can be distributed

15

Actor 1Mailbox

Actor 2Mailbox

Actor 3Mailbox

Fault Tolerant

Let it crash philosophy

Actor 1Mailbox

Actor 2Mailbox

Actor 3Mailbox

Actor 4Mailbox

A4 is linked to A2

A2 is warned when A4 crashes

A2 takes an action (restart A4)

Avoid defensive programming

Who implements Actors

20

Pykka

Celluloid ActorsRuby Objects

Same structure from classes

Runs over threads / fibers

Futures and Pools

Sync / Async Methods

25

When Actor crashes…

What if another actor could do

something?

Supervisors

30

Even if an Actor just terminates

ActorSupervisor

Restart Actor

Warn other Supervisor

Callbacks

Avoid begin… rescue... / if

Actions:

Must be finished to be CG’ed

35

Futures

Pool

Res 1 Res 2 Res 3

PoolRes 1

40

http://www.mikeperham.com/2015/10/14/should-you-use-celluloid/

Actors Reactor

Reactor Pattern

45

Handler 1

Handler 2

Dispatcher Handler 3

Handles service request

Delivered concurrently to handlers

Demultiplexing

Event

Event

Event

https://github.com/celluloid/nio4r

Server Celluloid:IOSupervisor

50

Important

Mutant Data Structure

Actor 1Mailbox

Actor 2Mailbox

Actor 3Mailbox

Microservices

55

Evaluate the best concurrency model

Celluloid Documentation

References

http://www.brianstorti.com/the-actor-model/

https://www.sitepoint.com/an-introduction-to-celluloid-part-i/

https://github.com/celluloid/celluloid-io

http://queroserdevlocaweb.com.br/

Thank you!

@celsocrivelaroSlides at http://crivelaro.me