Booting IoT with Grails

By Colin Harrington

@ColinHarrington

whoami

• Colin Harrington
• Grails Developer/Consultant @ OCI
• harringtonc@ociweb.com
• @ColinHarrington
• colin.harrington@gmail.com

Web Scale

Application Architecture

• One App to Rule them all
• Redundant, scaling out
• Clustering
• SOA/ESB
• Microservices
• Nanoservices

Where is exactly is your cloud?

• Metal!     \m/
• Virtual Metal (Virtual Machines)
• Virtual Clouds
• Virtual Private Computing
• IIAS
• PAAS
• Containerization
• {xen, docker, photon, coreOs, Snappy Core}

(Tomcat + app )*nodes = memory hog

• Fault tolerance
• Load balancers
• Clustered sessions/resources
• RAM is cheap (on servers)

Microservices?

• Splitting concerns
• extra latency between nodes
• death by 1000 JVMs?
• ..if you don't do it well.

500MB != micro

• Microservices present a problem for the memory intensive JVM
• Problems for Spring boot
• Demo on stage for the keynote was provisioned at 1GB and the apps used 500-700MB regularly

JDK7 & JDK8

• Different memory management models for Java 7 & 8
• http://www.slideshare.net/appdynamics/sb-java-java8memory
• Goodbye permgen = less overhead.. maybe
• less = more

Devices

AVR

• 8bit atmega328 chips
• 5v, 16mhz
• some are 3.3 & 8mhz
• Arduino UNO!
• Pro Mini's 

PIC32

• 32bit!! 
• floating point!
• 80Mhz - 200mhz
• some are 3.3 & 8mhz
• Chipkit UNO!

32 bit

• Intel?

ARM processors

• Phones
• Mini computers
• Apple Watch is ARM7 compat

Embedded Linux

Other higher-end options

• Raspberry Pi
• Raspberry Pi 2
• Beagle bone Black
• ODROID
• Intel NUC

Internet
of
Things

Devices

• Thermostats
• Sprinkler Systems
• TV systems
• ChromeCast
• Wink Devices
• Smart Things
• Amazon Echo
• Tweeting coffee pots

IoT :: Scale

Comm

Protocols

HTTP

• HTTP 1.0
• HTTP 1.1
• HTTP/2

HTTP Request

GET / HTTP/1.1
Host: whatever-name:1234
Accept: */*

Response

HTTP/1.1 200 OK

netcat to inspect?  nc -l 4444

802.11 ?

• mesh?  
• spectrum
• network layer
• zigbee
• zwave
• xbee
• bpl

MQTT

Websockets

TCP transports?

Grails on Pi2

• jdk8 out of the box (Raspbian)
• ARM7
• 1GB of mem
• Quad core @ 900Mhz
• HDMI, Video chipset
• Ethernet
• 4 USB 2.0
• micro SDIO

Empty Grails app

• ~200MB of RAM + Some PermGen

Grails Profiles

• https://github.com/grails/grails-profile-repository
• grails create-app myapp --profile=web-plugin
   
• Current Profiles:
  • plugin
  • web-api
  • web-micro
  • web-plugin
  • web

Grails Roadmap

• https://github.com/grails/grails-core/wiki/Roadmap
• Grails 3.2
  • Non-blocking, lightweight, lower memory Netty profile

Downloading the internet

• Maven?  
• Dependencies

• grails dependency-report

Build vs runtime

• build, test, compile time
• Different JVM dependencies

Demo Time

Components

• Raspberry Pi 2
• Grails 3 / jdk8 / h2 / runnable jar
• Phillips Hue
• Custom circuit-bent XBee Keypad (Arduino)
• XBee Explorer + Simple Serial protocol
• Fadecandy + NeoPixel 8x8 Matrix (LEDs!)
• Processing App (generating LED data)
• SMS (Twilio)

IoT Hub

• Grails 3
• RESTful Services
• RestClient
• Serial USB device (PureJavaComm)
• TCP clients (Fadecandy)
• H2 Database
• Runnable jar

Raspberry Pi 2

https://www.raspberrypi.org/products/raspberry-pi-2-model-b/

Phillips Hue

• 2 Bulbs (Zigbee)
• Base Station (Ethernet, Zigbee)
• Phllips Hue API
  • RESTful
  • Local

Garage Door Keypad

XBee

Circuit bending

Arduino

Serial Protocol

https://twitter.com/iothackday/status/523556799644176384

Fadecandy

https://www.adafruit.com/products/1689

NeoPixel Matrix 8x8 grid

https://www.adafruit.com/product/1487

Processing Sketch

• Processing 3
• 7 Modes
• HTTP Server (1 Socket)
• Controlled via HTTP
• JSON response
• OpenPixelControl

https://github.com/ColinHarrington/s2gx-2015-iot-demo-hub

@ColinHarrington hacking on iot and embedded devices with Grails. Awesome! #s2gx #springone2gx  -- @RyanVanderwerf