Leveraging Azure Cloud Services with Unity3D and WebAssembly

JaxNode October 2017

John Lyons

David Fekke

Speakers

Hosting Node on Azure

Game server

Unity3D

WebAssembly Intro

JAXNODE IS LOOKING

FOR SPEAKERS!!!

• Electron
• Go Lang
• Kubernetes, Swarm or Mesos
• Client Side frameworks
• NAPI
• Any other JavaScript topic

WebAssembly

WebAssembly

• What the Heck is It?
• Direct Successor to ASM.js
• Compiler Target for the Web
• Runs on Web and Node.js

WebAssembly history

• ASM.js tool from Mozilla to compile their C/C++ code into a low-level JS format 
• Effort began a couple of years ago to incorporate a binary executable format in all browsers 
• Firefox added support in March 2017
• All major browser vendors now support it as of October 2017

WASM format

• Compiles to binary format
• Has an intermediate WAST format

int add(int a, int b) {
  return a + b;
}

C code

WAST format

(module
 (table 0 anyfunc)
 (memory $0 1)
 (export "memory" (memory $0))
 (export "_Z3addii" (func $_Z3addii))
 (func $_Z3addii (; 0 ;) (param $0 i32) (param $1 i32) (result i32)
  (i32.add
   (get_local $1)
   (get_local $0)
  )
 )
)

Wasm Assembly

wasm-function[0]:
  sub rsp, 8                            ; 0x000000 48 83 ec 08
  mov ecx, esi                          ; 0x000004 8b ce
  mov eax, ecx                          ; 0x000006 8b c1
  add eax, edi                          ; 0x000008 03 c7
  nop                                   ; 0x00000a 66 90
  add rsp, 8                            ; 0x00000c 48 83 c4 08
  ret                                   ; 0x000010 c3

DEMO

Web use cases

• Eliminate need for plugins
• Support custom codecs
• Games
• Image processing
• AI/Machine Learning

Node use cases

• Replace native modules with WASM
• No need to create separate executables for each chip architecture or OS
• Replace processor intensive pure JS modules

How can we use today

• Unity3D has web export
• Unreal engine can run in WASM
• emscripten to compile to WASM

What is missing in 1.0?

• No native Web API support
• Single Threaded
• No GC
• No SIMD support

Questions?

And Now,
John Lyons!

NodeJS, Websockets, Unity3d

Websockets

WebSockets, part of the HTML5 specification, enables two-way communication between web pages and a remote host. (https://tools.ietf.org/html/rfc6455)

• Reduce unnecessary network traffic and latency using full-duplex through a single connection (instead of two)
• Streaming through proxies and firewalls, supporting simultaneously upstream and downstream communication
• Backward compatible with the pre-WebSocket world by switching from an HTTP connection to WebSockets (degrades)

The good (read bad) old days of browser based games

Long Polling - server holds the request open until new data is available. Once available, the server responds and sends the new information.

Flash Socket uses a flash object to establish a connection to the WebSocket server and communicates using the WebSocket protocol. This means an additional Flash object (SWF files) will need to be leveraged.

WebSocket Upgrade Path

• http(s) handshake
• Upgrade to Websocket connection
• Full duplex (bidirectional comms) over TCP

Websocket vs UDP/TCP

• The overhead induced by TCP/IP and TLS in particular can dwarf the overhead of WebSocket itself.

• Applications can use application-level message batching to effectively reduce the overhead that can be induced by TCP/IP and TLS.

• WSS gives you easy encryption

• HMAC-SHA256 gives you payload signing

• Websockets make streaming easy.

• Cell phone IP's aren't static there proxied

• Sends strings, buffered arrays, and blobs

• No need for port mapping , UPNP, etc.

Benchmarks Here:

https://crossbario.com/blog/Dissecting-Websocket-Overhead/

Another Great write up:

https://stackoverflow.com/questions/13040752/websockets-udp-and-benchmarks

Common Websocket implementations 

• socket.io
• pomelo
• ws

A word on Azure App Services

References

• http://www.websocket.org/aboutwebsocket.html
• http://www.websocket.org/quantum.html
• http://buildnewgames.com/websockets/
• http://ithare.com/tcp-and-websockets-for-games/
• https://crossbario.com/blog/Dissecting-Websocket-Overhead/
• https://github.com/NetEase/pomelo
• https://github.com/websockets/ws
• https://tools.ietf.org/html/rfc6455
• https://developer.valvesoftware.com/wiki/Latency_Compensating_Methods_in_Client/Server_In-game_Protocol_Design_and_Optimization

I'm BORED , let's look at some code.