Embed Size (px)
Citation preview
Developing IoT Applications in the Fog: a Distributed
Dataflow ApproachNam Giang ([email protected]), Michael Blackstock, Rodger
Lea, Victor LeungUniversity of British Columbia
IoT2015, Seoul Korea
Cloud-based IoT applications
a combination of embedded web services coordinated by the cloud
HTTP
CoAP
MQTT
HTTP
Problems of Cloud-based IoT
Timeliness?Redundancy?Scalability?Security?
HTTP
MQTT
CoAPHTTP
Same room
300ms500ms
Smart gateway-based IoT
HTTP
Same network
Local execution
MQTT
HTTP
Fog Computing
Distributed computation
System architecture for the IoT
aka. In-network Processing, Cloudlets
Local execution
Intermediate execution
FOG
Fog-based IoT apps
Local execution
Intermediate execution
Four computational parts1: gesture recog.2: turn light on3: if home, update Twitter4: log activity
Challenges: Perception-Action Cycle
FOG
FOG
fog-to-fog
fog-to-cloud
cloud-to-fog
cloud-to-cloud
Challenges: Heterogeneity
FOG
Horizontal Heterogeneity
Ver
tical
Het
erog
enei
ty
Resourceful devices
Constrained devices
Compute NodesIO Nodes Edge Nodes
Challenges: Scalability
Largely distributed execution environment
Pull de
ploym
ent
Challenges: Mobility
Mobility of the executors
Backups of executors?
Local execution
Intermediate execution
FOG
Distributed Flow-based (Dataflow) Model
Sensor
Actuator
Web Service
RoutinesRoutines
Web Service
ActuatorSame Network
On Cloud
At Specific location
Same Device
- reusable nodes- no centralized coord.- simple IO model
Dataflow Programming Model
- Well defined execution unitsinputs outputs
- Acyclic graphs
- Was created for concurrent execution, later on was used as a coordination language
- Customizable nodes library
Node-RED project http://nodered.org
FRED project https://fred.sensetecnic.com
Distributed Node-RED
Node-RED CloudMaster Flow
...
Raspberry Pis
Master Flow
Special node for inter-devices wiring
Experience with DNR
TI SensorTag
Lessons learned
● Flow-based model is generic enough to accommodate the heterogeneity but still supports domain-specific applications
● Node-level development is domain-specific● Node-RED project is written in JavaScript - very
easy to develop new nodes
Open problems
● Inter-nodes communication is hard: define “same room/building” communication?
● Distributed Service Discovery/Resource Directory● Multiple flows per device
○ resource conflicts
Conclusion
- Fog computing is a promising architectural model for the IoT
- New challenges when developing IoT applications in the Fog
- Distributed Dataflow model a promising approach to supporting Fog-based IoT applications
Thank you
