Why HTTP Won’t Work For IoTTim Kellogg

Principal Software Engineer

@kellogh

About Me

Backend Cloud Services

Simple Designs

Abstractions Are Good

Internet of Things

Embedded Internet IoT

Internet of Things

Constrained environments• Constrained memory footprint MCUs• Embedded Linux• No OS

Unreliable network connectivity

Constrained devices

Telemetry

Device to server

Sensor readings

Big data & analytics

Telemetry

BrokerPublishCloud

ConnectorsSubscribe

Salesforce1Platform

Subscribe

Devices

Sensors

HTTPFor request / response

HTTP

Client ServerRequest

Response

HTTP

Consumer must be available at all times

Publisher needs to know the exact destination

Publisher depends on the response status

MQTT

Broker must be available at all times• Doesn’t do any processing, failure is uncommon

Publisher and subscriber are decoupled• Publisher publishes at it’s leisure• Subscriber processes messages at it’s leisure

Publisher does not care who (if anyone) it’s publishing to

Publisher doesn’t care about the result of processing

Quality of Service (QoS)

0 – fire and forget

1 – Guaranteed delivery at least once

2 – Guaranteed delivery exactly once• Can be easily implemented client-side by

using QoS 1 to increase throughput

Topics

Hierarchical• a/b/c• com.example/sensors/sen546/temp• CTL/com.example/sensors/sen546

“+” matches single level• com.example/sensors/+/temp• +/sensors/sen546

“#” matches many level, must be at end• com.example/sensors/#• CTL/com.example/#

MQTT Features

Last will and testament• Unexpected disconnects

Retained messages• Infrequently published values

MQTT-SN

MQTT for Sensor Networks

UDP + 6LoWPAN

Gateway

Configuration-free discovery

MQTT-SN

Gateway

Broker

CoAPA lighter version of HTTP with some extra bells and whistles

Constrained Application Protocol

REST

HTTP mappings for proxy servers

Very lightweight messages

UDP + 6LoWPAN

Confirmable messages

Additional response messages sent whenever the resource changes

No polling

GET+Observe

Resources

IoT Zone

MQTT & CoAP• http://iot.eclipse.org/ • https://app.thingfabric.com/

Hardware• http://www.kelloggsresearchlabs.com/PressRele

aseGenerator

@kellogh

APPENDIX

CONFIDENTIAL - 2lemetry, LLC

We power the connected enterprise

• 2lemetry is an IoT technology and solutions company that powers the connected enterprise, tying people, processes, data and devices together—transforming raw data into real-time actionable intelligence.

• Founded 2011—spun off from hardware manufacturer

• 100% Focus on Internet of Things—with a “cloud first” focus

Technology - ThingFabric

Broker Layer

Data Storage

CEP EngineRules Engine

REST API

Regional Load Balancing

• Historical data storage• Automation replication• Schemaless

• Find trends• Run computations• Build complex models

• HTTP webhook• Republish rules• SMS/Email• Reformat payloads

• Supports custom protocols• Supports MQTT, Stomp, CoAP• Balanced by geographical response time

2lemetry technology, solutions, partners and expertise to provide an end to end solution

Technology2lemetry Device Cloud Platform

SolutionsEnterprise system integration tools

Digital signage

Proximity sensing

Facial recognition

PartnersAcross entire IoT project lifecycle

Sales channel

ExpertiseIoT strategy

Integration expertise and application development

Managed service and support

CONFIDENTIAL - 2lemetry, LLC