Erlang +

Message Queue+

HTML 5 Tech

=

Over-engineered Chat Server

WhatCowboy ?https://github.com/extend/cowboy

Small, fast modular web server written in erlang.

WhatGen Bunny https://github.com/mochi/gen_bunny

RabbitMQ client library for simple pubsub in erlang.

WhatWebsocket ?https://www.websocket.org/

Bi-directional web communication mechanism.

Over Architecturing

You want it.I deliver !

Server

Moving parts

Cowboy

Gen Bunny

Browser

Client

Moving parts

Cowboy

Gen Bunny

Browser

Websockets

TechnicalDetour

Client

Moving parts

BrowserBrowser

Server

HTTP

Port 80Port 80

Client

Moving parts

BrowserBrowser

Server

WS

UpgradeUpgradePort 80Port 80

WHY ?

WORKS WITH EXISTING PROXIES

Client JS

Data is live chat stream

JS Connection

wsUrl = "ws://server:8081/websocket";

websocket = new WebSocket(wsUrl);

Websocket Setupwebsocket = new WebSocket(wsURL);

websocket.onopen = ...

websocket.onmessage =

function(evt){ onMessage(e) };

websocket.onerror = ...

onMessage Handler

function onMessage(e) {

Msg = '<p>' + txt + '</p>'

$('#output').prepend(Msg);

};

Smooth

Yeah

Server SideServer

WS

Cowboy

What comes to mind ?

Kid Rock

Fresh Leather

Pretty Lil' web server

Cowboy

Routes, REST, middleware, web sockets and more.

Cowboy

follows OTP principals.

Cowboy WS

Required Callbacks init websocket_init websocket_handle websocket_info websocket_terminate

Cowboy WS

initUpgrades from http → web socket

Cowboy WS

init({tcp, http}, _Req, _Opts) →{upgrade,protocol,cowboy_websocket}.

Cowboy WS

websocket_initRun on each connection.

Cowboy WS

websocket_init(_Name, Req, _Opts) → Pid = consumer:start_link(), {ok, Req, #state{pid=Pid}}.

Cowboy WS

websocket_handleRecv data from client, optionally return data.

Cowboy WS

websocket_handle(Data, Req, State) → {text, Msg} = Data, {reply, {text, << "recv: ", Msg/binary >>}, Req,

State};

Cowboy WS

websocket_infoLive Push data to client

Cowboy WS

websocket_info(Data, Req, State) → {reply, {text, Data}, Req,State};

Sending to RabbitMQRabbitMQ

websocket_handle

Recv from RabbitMQRabbitMQ

websocket_info

gen_bunnyCONSUMER

Message Queues

gen bunny

gen_bunny

follows OTP principals.

callbacks

Required:● handle_message

● init ● handle_call● handle_cast● handle_info● terminate

callbacks

handle_messageHandle messages from the message subscribed message queue.

callbacks

handle_message(Msg, State) →NewState = act_on_msg(Msg,State){noreply, NewState};

MQ perspectiveEx

chan

ge

Exchange“Fanout”

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Live demoWireless Network:Name: rabbitPassword: carrot

VISIT:http://10.1.1.1:8081/

Benchmarking

Method:

Connect to WebsocketWait for signal.Send 100 messages.Receive all messages

Benchmarking

Results:(Didn't get this done in time, sorry)

0.5 1 1.5 2 2.5 3 3.5 4 4.50

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Column 1

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Source Codegithub.com/wmeal ing/

bunny-cowboy-websocket